diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc index a78fd45b4f0..322d24100cd 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc @@ -2,20 +2,16 @@ [appendix] [[common-application-properties]] == Common application properties -Various properties can be specified inside your `application.properties` file, inside -your `application.yml` file, or as command line switches. This appendix provides a list -of common Spring Boot properties and references to the underlying classes that consume -them. +Various properties can be specified inside your `application.properties` file, inside your `application.yml` file, or as command line switches. +This appendix provides a list of common Spring Boot properties and references to the underlying classes that consume them. -TIP: Spring Boot provides various conversion mechanism with advanced value formatting, -make sure to review <>. +TIP: Spring Boot provides various conversion mechanism with advanced value formatting,make sure to review <>. -NOTE: Property contributions can come from additional jar files on your classpath, so you -should not consider this an exhaustive list. Also, you can define your own properties. +NOTE: Property contributions can come from additional jar files on your classpath, so you should not consider this an exhaustive list. +Also, you can define your own properties. -WARNING: This sample file is meant as a guide only. Do **not** copy and paste the entire -content into your application. Rather, pick only the properties that you need. +WARNING: This sample file is meant as a guide only. Do **not** copy and paste the entire content into your application. +Rather, pick only the properties that you need. [source,properties,indent=0,subs="verbatim,attributes,macros"] diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-auto-configuration-classes.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-auto-configuration-classes.adoc index bbf1f587d1d..3b42ec93dcb 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-auto-configuration-classes.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-auto-configuration-classes.adoc @@ -1,11 +1,9 @@ [appendix] [[auto-configuration-classes]] == Auto-configuration classes -Here is a list of all auto-configuration classes provided by Spring Boot, with links to -documentation and source code. Remember to also look at the conditions report in your -application for more details of which features are switched on. -(To do so, start the app with `--debug` or `-Ddebug` or, in an Actuator application, use -the `conditions` endpoint). +Here is a list of all auto-configuration classes provided by Spring Boot, with links to documentation and source code. +Remember to also look at the conditions report in your application for more details of which features are switched on. +(To do so, start the app with `--debug` or `-Ddebug` or, in an Actuator application, use the `conditions` endpoint). diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-configuration-metadata.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-configuration-metadata.adoc index 076d0c9118a..de8f09f6e05 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-configuration-metadata.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-configuration-metadata.adoc @@ -1,24 +1,18 @@ [appendix] [[configuration-metadata]] == Configuration Metadata -Spring Boot jars include metadata files that provide details of all supported -configuration properties. The files are designed to let IDE developers offer -contextual help and "`code completion`" as users are working with `application.properties` -or `application.yml` files. +Spring Boot jars include metadata files that provide details of all supported configuration properties. +The files are designed to let IDE developers offer contextual help and "`code completion`" as users are working with `application.properties` or `application.yml` files. -The majority of the metadata file is generated automatically at compile time by -processing all items annotated with `@ConfigurationProperties`. However, it is possible -to <> -for corner cases or more advanced use cases. +The majority of the metadata file is generated automatically at compile time by processing all items annotated with `@ConfigurationProperties`. +However, it is possible to <> for corner cases or more advanced use cases. [[configuration-metadata-format]] === Metadata Format -Configuration metadata files are located inside jars under -`META-INF/spring-configuration-metadata.json` They use a simple JSON format with items -categorized under either "`groups`" or "`properties`" and additional values hints -categorized under "hints", as shown in the following example: +Configuration metadata files are located inside jars under `META-INF/spring-configuration-metadata.json`. +They use a simple JSON format with items categorized under either "`groups`" or "`properties`" and additional values hints categorized under "hints", as shown in the following example: [source,json,indent=0] ---- @@ -83,8 +77,7 @@ categorized under "hints", as shown in the following example: ---- Each "`property`" is a configuration item that the user specifies with a given value. -For example, `server.port` and `server.address` might be specified in -`application.properties`, as follows: +For example, `server.port` and `server.address` might be specified in `application.properties`, as follows: [source,properties,indent=0] ---- @@ -92,151 +85,136 @@ For example, `server.port` and `server.address` might be specified in server.address=127.0.0.1 ---- -The "`groups`" are higher level items that do not themselves specify a value but instead -provide a contextual grouping for properties. For example, the `server.port` and -`server.address` properties are part of the `server` group. +The "`groups`" are higher level items that do not themselves specify a value but instead provide a contextual grouping for properties. +For example, the `server.port` and `server.address` properties are part of the `server` group. -NOTE: It is not required that every "`property`" has a "`group`". Some properties might -exist in their own right. +NOTE: It is not required that every "`property`" has a "`group`". Some properties might exist in their own right. -Finally, "`hints`" are additional information used to assist the user in configuring a -given property. For example, when a developer is configuring the -`spring.jpa.hibernate.ddl-auto` property, a tool can use the hints to offer some -auto-completion help for the `none`, `validate`, `update`, `create`, and `create-drop` -values. +Finally, "`hints`" are additional information used to assist the user in configuring a given property. +For example, when a developer is configuring the `spring.jpa.hibernate.ddl-auto` property, a tool can use the hints to offer some auto-completion help for the `none`, `validate`, `update`, `create`, and `create-drop` values. [[configuration-metadata-group-attributes]] ==== Group Attributes -The JSON object contained in the `groups` array can contain the attributes shown in the -following table: +The JSON object contained in the `groups` array can contain the attributes shown in the following table: [cols="1,1,4"] |=== -|Name | Type |Purpose +| Name | Type | Purpose -|`name` +| `name` | String | The full name of the group. This attribute is mandatory. -|`type` +| `type` | String -| The class name of the data type of the group. For example, if the group were based - on a class annotated with `@ConfigurationProperties`, the attribute would contain the - fully qualified name of that class. If it were based on a `@Bean` method, it would be - the return type of that method. If the type is not known, the attribute may be omitted. +| The class name of the data type of the group. + For example, if the group were based on a class annotated with `@ConfigurationProperties`, the attribute would contain the fully qualified name of that class. + If it were based on a `@Bean` method, it would be the return type of that method. + If the type is not known, the attribute may be omitted. -|`description` +| `description` | String -| A short description of the group that can be displayed to users. If not description is - available, it may be omitted. It is recommended that descriptions be short paragraphs, - with the first line providing a concise summary. The last line in the description should - end with a period (`.`). +| A short description of the group that can be displayed to users. + If not description is available, it may be omitted. + It is recommended that descriptions be short paragraphs, with the first line providing a concise summary. + The last line in the description should end with a period (`.`). -|`sourceType` +| `sourceType` | String -| The class name of the source that contributed this group. For example, if the group - were based on a `@Bean` method annotated with `@ConfigurationProperties`, this attribute - would contain the fully qualified name of the `@Configuration` class that contains the - method. If the source type is not known, the attribute may be omitted. +| The class name of the source that contributed this group. + For example, if the group were based on a `@Bean` method annotated with `@ConfigurationProperties`, this attribute would contain the fully qualified name of the `@Configuration` class that contains the method. + If the source type is not known, the attribute may be omitted. -|`sourceMethod` +| `sourceMethod` | String -| The full name of the method (include parenthesis and argument types) that contributed - this group (for example, the name of a `@ConfigurationProperties` annotated `@Bean` - method). If the source method is not known, it may be omitted. +| The full name of the method (include parenthesis and argument types) that contributed this group (for example, the name of a `@ConfigurationProperties` annotated `@Bean` method). + If the source method is not known, it may be omitted. |=== [[configuration-metadata-property-attributes]] ==== Property Attributes -The JSON object contained in the `properties` array can contain the attributes described -in the following table: +The JSON object contained in the `properties` array can contain the attributes described in the following table: [cols="1,1,4"] |=== -|Name | Type |Purpose +| Name | Type | Purpose -|`name` +| `name` | String -| The full name of the property. Names are in lower-case period-separated form (for - example, `server.address`). This attribute is mandatory. +| The full name of the property. + Names are in lower-case period-separated form (for example, `server.address`). + This attribute is mandatory. -|`type` +| `type` | String -| The full signature of the data type of the property (for example, `java.lang.String`) - but also a full generic type (such as `java.util.Map`). - You can use this attribute to guide the user as to the types of values that they can - enter. For consistency, the type of a primitive is specified by using its wrapper - counterpart (for example, `boolean` becomes `java.lang.Boolean`). Note that this class - may be a complex type that gets converted from a `String` as values are bound. If the - type is not known, it may be omitted. +| The full signature of the data type of the property (for example, `java.lang.String`) but also a full generic type (such as `java.util.Map`). + You can use this attribute to guide the user as to the types of values that they can enter. + For consistency, the type of a primitive is specified by using its wrapper counterpart (for example, `boolean` becomes `java.lang.Boolean`). + Note that this class may be a complex type that gets converted from a `String` as values are bound. + If the type is not known, it may be omitted. -|`description` +| `description` | String -| A short description of the group that can be displayed to users. If no description is - available, it may be omitted. It is recommended that descriptions be short paragraphs, - with the first line providing a concise summary. The last line in the description should - end with a period (`.`). +| A short description of the group that can be displayed to users. + If no description is available, it may be omitted. + It is recommended that descriptions be short paragraphs, with the first line providing a concise summary. + The last line in the description should end with a period (`.`). -|`sourceType` +| `sourceType` | String -| The class name of the source that contributed this property. For example, if the - property were from a class annotated with `@ConfigurationProperties`, this attribute - would contain the fully qualified name of that class. If the source type is unknown, it - may be omitted. +| The class name of the source that contributed this property. + For example, if the property were from a class annotated with `@ConfigurationProperties`, this attribute would contain the fully qualified name of that class. + If the source type is unknown, it may be omitted. -|`defaultValue` +| `defaultValue` | Object -| The default value, which is used if the property is not specified. If the type of the - property is an array, it can be an array of value(s). If the default value is unknown, - it may be omitted. +| The default value, which is used if the property is not specified. + If the type of the property is an array, it can be an array of value(s). + If the default value is unknown, it may be omitted. -|`deprecation` +| `deprecation` | Deprecation -| Specify whether the property is deprecated. If the field is not deprecated or if that - information is not known, it may be omitted. The next table offers more detail about - the `deprecation` attribute. +| Specify whether the property is deprecated. + If the field is not deprecated or if that information is not known, it may be omitted. + The next table offers more detail about the `deprecation` attribute. |=== -The JSON object contained in the `deprecation` attribute of each `properties` element can -contain the following attributes: +The JSON object contained in the `deprecation` attribute of each `properties` element can contain the following attributes: [cols="1,1,4"] |=== -|Name | Type |Purpose +| Name | Type | Purpose -|`level` -|String -|The level of deprecation, which can be either `warning` (the default) or `error`. When a - property has a `warning` deprecation level, it should still be bound in the environment. - However, when it has an `error` deprecation level, the property is no longer managed and - is not bound. +| `level` +| String +| The level of deprecation, which can be either `warning` (the default) or `error`. + When a property has a `warning` deprecation level, it should still be bound in the environment. + However, when it has an `error` deprecation level, the property is no longer managed and is not bound. -|`reason` -|String -|A short description of the reason why the property was deprecated. If no reason is - available, it may be omitted. It is recommended that descriptions be short paragraphs, - with the first line providing a concise summary. The last line in the description should - end with a period (`.`). +| `reason` +| String +| A short description of the reason why the property was deprecated. + If no reason is available, it may be omitted. + It is recommended that descriptions be short paragraphs, with the first line providing a concise summary. + The last line in the description should end with a period (`.`). -|`replacement` -|String -|The full name of the property that _replaces_ this deprecated property. If there is no - replacement for this property, it may be omitted. +| `replacement` +| String +| The full name of the property that _replaces_ this deprecated property. + If there is no replacement for this property, it may be omitted. |=== -NOTE: Prior to Spring Boot 1.3, a single `deprecated` boolean attribute can be used -instead of the `deprecation` element. This is still supported in a deprecated fashion and -should no longer be used. If no reason and replacement are available, an empty -`deprecation` object should be set. +NOTE: Prior to Spring Boot 1.3, a single `deprecated` boolean attribute can be used instead of the `deprecation` element. +This is still supported in a deprecated fashion and should no longer be used. +If no reason and replacement are available, an empty `deprecation` object should be set. -Deprecation can also be specified declaratively in code by adding the -`@DeprecatedConfigurationProperty` annotation to the getter exposing the deprecated -property. For instance, assume that the `app.acme.target` property was confusing and -was renamed to `app.acme.name`. The following example shows how to handle that situation: +Deprecation can also be specified declaratively in code by adding the `@DeprecatedConfigurationProperty` annotation to the getter exposing the deprecated property. +For instance, assume that the `app.acme.target` property was confusing and was renamed to `app.acme.name`. +The following example shows how to handle that situation: [source,java,indent=0] ---- @@ -262,119 +240,103 @@ was renamed to `app.acme.name`. The following example shows how to handle that s } ---- -NOTE: There is no way to set a `level`. `warning` is always assumed, since code is still -handling the property. +NOTE: There is no way to set a `level`. +`warning` is always assumed, since code is still handling the property. -The preceding code makes sure that the deprecated property still works (delegating -to the `name` property behind the scenes). Once the `getTarget` and `setTarget` -methods can be removed from your public API, the automatic deprecation hint in the -metadata goes away as well. If you want to keep a hint, adding manual metadata with -an `error` deprecation level ensures that users are still informed about that property. +The preceding code makes sure that the deprecated property still works (delegating to the `name` property behind the scenes). +Once the `getTarget` and `setTarget` methods can be removed from your public API, the automatic deprecation hint in the metadata goes away as well. +If you want to keep a hint, adding manual metadata with an `error` deprecation level ensures that users are still informed about that property. Doing so is particularly useful when a `replacement` is provided. [[configuration-metadata-hints-attributes]] ==== Hint Attributes -The JSON object contained in the `hints` array can contain the attributes shown in the -following table: +The JSON object contained in the `hints` array can contain the attributes shown in the following table: [cols="1,1,4"] |=== -|Name | Type |Purpose +| Name | Type | Purpose -|`name` +| `name` | String -| The full name of the property to which this hint refers. Names are in lower-case - period-separated form (such as `spring.mvc.servlet.path`). If the property refers to a map - (such as `system.contexts`), the hint either applies to the _keys_ of the map - (`system.context.keys`) or the _values_ (`system.context.values`) of the map. This - attribute is mandatory. +| The full name of the property to which this hint refers. + Names are in lower-case period-separated form (such as `spring.mvc.servlet.path`). + If the property refers to a map (such as `system.contexts`), the hint either applies to the _keys_ of the map (`system.context.keys`) or the _values_ (`system.context.values`) of the map. + This attribute is mandatory. -|`values` +| `values` | ValueHint[] -| A list of valid values as defined by the `ValueHint` object (described in the next - table). Each entry defines the value and may have a description. +| A list of valid values as defined by the `ValueHint` object (described in the next table). + Each entry defines the value and may have a description. -|`providers` +| `providers` | ValueProvider[] -| A list of providers as defined by the `ValueProvider` object (described later in this - document). Each entry defines the name of the provider and its parameters, if any. - +| A list of providers as defined by the `ValueProvider` object (described later in this document). + Each entry defines the name of the provider and its parameters, if any. |=== -The JSON object contained in the `values` attribute of each `hint` element can contain -the attributes described in the following table: +The JSON object contained in the `values` attribute of each `hint` element can contain the attributes described in the following table: [cols="1,1,4"] |=== -|Name | Type |Purpose +| Name | Type | Purpose -|`value` +| `value` | Object -| A valid value for the element to which the hint refers. If the type of the property is - an array, it can also be an array of value(s). This attribute is mandatory. +| A valid value for the element to which the hint refers. + If the type of the property is an array, it can also be an array of value(s). + This attribute is mandatory. -|`description` +| `description` | String -| A short description of the value that can be displayed to users. If no description is - available, it may be omitted . It is recommended that descriptions be short paragraphs, - with the first line providing a concise summary. The last line in the description should - end with a period (`.`). +| A short description of the value that can be displayed to users. + If no description is available, it may be omitted. + It is recommended that descriptions be short paragraphs, with the first line providing a concise summary. + The last line in the description should end with a period (`.`). |=== -The JSON object contained in the `providers` attribute of each `hint` element can contain -the attributes described in the following table: +The JSON object contained in the `providers` attribute of each `hint` element can contain the attributes described in the following table: [cols="1,1,4"] |=== |Name | Type |Purpose -|`name` +| `name` | String -| The name of the provider to use to offer additional content assistance for the element - to which the hint refers. +| The name of the provider to use to offer additional content assistance for the element to which the hint refers. -|`parameters` +| `parameters` | JSON object -| Any additional parameter that the provider supports (check the documentation of the - provider for more details). +| Any additional parameter that the provider supports (check the documentation of the provider for more details). |=== [[configuration-metadata-repeated-items]] ==== Repeated Metadata Items -Objects with the same "`property`" and "`group`" name can appear multiple times within a -metadata file. For example, you could bind two separate classes to the same prefix, with -each having potentially overlapping property names. While the same names appearing in the -metadata multiple times should not be common, consumers of metadata should take care to -ensure that they support it. +Objects with the same "`property`" and "`group`" name can appear multiple times within a metadata file. For example, you could bind two separate classes to the same prefix, with each having potentially overlapping property names. +While the same names appearing in the metadata multiple times should not be common, consumers of metadata should take care to ensure that they support it. [[configuration-metadata-providing-manual-hints]] === Providing Manual Hints -To improve the user experience and further assist the user in configuring a given -property, you can provide additional metadata that: +To improve the user experience and further assist the user in configuring a given property, you can provide additional metadata that: * Describes the list of potential values for a property. -* Associates a provider, to attach a well defined semantic to a property, so that a tool -can discover the list of potential values based on the project's context. +* Associates a provider, to attach a well defined semantic to a property, so that a tool can discover the list of potential values based on the project's context. ==== Value Hint -The `name` attribute of each hint refers to the `name` of a property. In the -<>, we provide five values -for the `spring.jpa.hibernate.ddl-auto` property: `none`, `validate`, `update`, `create`, -and `create-drop`. Each value may have a description as well. +The `name` attribute of each hint refers to the `name` of a property. +In the <>, we provide five values for the `spring.jpa.hibernate.ddl-auto` property: `none`, `validate`, `update`, `create`, and `create-drop`. +Each value may have a description as well. -If your property is of type `Map`, you can provide hints for both the keys and the -values (but not for the map itself). The special `.keys` and `.values` suffixes must -refer to the keys and the values, respectively. +If your property is of type `Map`, you can provide hints for both the keys and the values (but not for the map itself). +The special `.keys` and `.values` suffixes must refer to the keys and the values, respectively. -Assume a `sample.contexts` maps magic `String` values to an integer, as shown in the -following example: +Assume a `sample.contexts` maps magic `String` values to an integer, as shown in the following example: [source,java,indent=0] ---- @@ -386,9 +348,8 @@ following example: } ---- -The magic values are (in this example) are `sample1` and `sample2`. In order to offer -additional content assistance for the keys, you could add the following JSON to -<>: +The magic values are (in this example) are `sample1` and `sample2`. +In order to offer additional content assistance for the keys, you could add the following JSON to <>: [source,json,indent=0] ---- @@ -407,66 +368,59 @@ additional content assistance for the keys, you could add the following JSON to ]} ---- -TIP: We recommend that you use an `Enum` for those two values instead. If your IDE -supports it, this is by far the most effective approach to auto-completion. +TIP: We recommend that you use an `Enum` for those two values instead. +If your IDE supports it, this is by far the most effective approach to auto-completion. ==== Value Providers -Providers are a powerful way to attach semantics to a property. In this section, we -define the official providers that you can use for your own hints. However, your favorite -IDE may implement some of these or none of them. Also, it could eventually provide its -own. +Providers are a powerful way to attach semantics to a property. +In this section, we define the official providers that you can use for your own hints. +However, your favorite IDE may implement some of these or none of them. +Also, it could eventually provide its own. -NOTE: As this is a new feature, IDE vendors must catch up with how it works. Adoption -times naturally vary. +NOTE: As this is a new feature, IDE vendors must catch up with how it works. +Adoption times naturally vary. The following table summarizes the list of supported providers: [cols="2,4"] |=== -|Name | Description +| Name | Description -|`any` -|Permits any additional value to be provided. +| `any` +| Permits any additional value to be provided. -|`class-reference` -|Auto-completes the classes available in the project. Usually constrained by a base - class that is specified by the `target` parameter. +| `class-reference` +| Auto-completes the classes available in the project. + Usually constrained by a base class that is specified by the `target` parameter. -|`handle-as` -|Handles the property as if it were defined by the type defined by the mandatory `target` - parameter. +| `handle-as` +| Handles the property as if it were defined by the type defined by the mandatory `target` parameter. -|`logger-name` -|Auto-completes valid logger names and - <>. Typically, - package and class names available in the current project can be auto-completed as well as - defined groups. +| `logger-name` +| Auto-completes valid logger names and <>. + Typically, package and class names available in the current project can be auto-completed as well as defined groups. -|`spring-bean-reference` -|Auto-completes the available bean names in the current project. Usually constrained - by a base class that is specified by the `target` parameter. - -|`spring-profile-name` -|Auto-completes the available Spring profile names in the project. +| `spring-bean-reference` +| Auto-completes the available bean names in the current project. + Usually constrained by a base class that is specified by the `target` parameter. +| `spring-profile-name` +| Auto-completes the available Spring profile names in the project. |=== -TIP: Only one provider can be active for a given property, but you can specify several -providers if they can all manage the property _in some way_. Make sure to place the most -powerful provider first, as the IDE must use the first one in the JSON section that it -can handle. If no provider for a given property is supported, no special content -assistance is provided, either. +TIP: Only one provider can be active for a given property, but you can specify several providers if they can all manage the property _in some way_. +Make sure to place the most powerful provider first, as the IDE must use the first one in the JSON section that it can handle. +If no provider for a given property is supported, no special content assistance is provided, either. ===== Any -The special **any** provider value permits any additional values to be provided. Regular -value validation based on the property type should be applied if this is supported. +The special **any** provider value permits any additional values to be provided. +Regular value validation based on the property type should be applied if this is supported. -This provider is typically used if you have a list of values and any extra values -should still be considered as valid. +This provider is typically used if you have a list of values and any extra values should still be considered as valid. The following example offers `on` and `off` as auto-completion values for `system.state`: @@ -495,29 +449,28 @@ The following example offers `on` and `off` as auto-completion values for `syste Note that, in the preceding example, any other value is also allowed. ===== Class Reference -The **class-reference** provider auto-completes classes available in the project. This -provider supports the following parameters: +The **class-reference** provider auto-completes classes available in the project. +This provider supports the following parameters: [cols="1,1,2,4"] |=== -|Parameter |Type |Default value |Description +| Parameter | Type | Default value | Description -|`target` -|`String` (`Class`) -|_none_ -|The fully qualified name of the class that should be assignable to the chosen value. - Typically used to filter out-non candidate classes. Note that this information can - be provided by the type itself by exposing a class with the appropriate upper bound. +| `target` +| `String` (`Class`) +| _none_ +| The fully qualified name of the class that should be assignable to the chosen value. + Typically used to filter out-non candidate classes. + Note that this information can be provided by the type itself by exposing a class with the appropriate upper bound. -|`concrete` -|`boolean` -|true -|Specify whether only concrete classes are to be considered as valid candidates. +| `concrete` +| `boolean` +| true +| Specify whether only concrete classes are to be considered as valid candidates. |=== -The following metadata snippet corresponds to the standard `server.servlet.jsp.class-name` -property that defines the `JspServlet` class name to use: +The following metadata snippet corresponds to the standard `server.servlet.jsp.class-name` property that defines the `JspServlet` class name to use: [source,json,indent=0] ---- @@ -539,43 +492,34 @@ property that defines the `JspServlet` class name to use: ===== Handle As -The **handle-as** provider lets you substitute the type of the property to a more -high-level type. This typically happens when the property has a `java.lang.String` type, -because you do not want your configuration classes to rely on classes that may not be -on the classpath. This provider supports the following parameters: +The **handle-as** provider lets you substitute the type of the property to a more high-level type. +This typically happens when the property has a `java.lang.String` type, because you do not want your configuration classes to rely on classes that may not be on the classpath. +This provider supports the following parameters: [cols="1,1,2,4"] |=== -|Parameter |Type |Default value |Description +| Parameter | Type | Default value | Description | **`target`** | `String` (`Class`) -|_none_ -|The fully qualified name of the type to consider for the property. This parameter is - mandatory. +| _none_ +| The fully qualified name of the type to consider for the property. + This parameter is mandatory. |=== The following types can be used: -* Any `java.lang.Enum`: Lists the possible values for the property. (We recommend - defining the property with the `Enum` type, as no further hint should be required for - the IDE to auto-complete the values.) -* `java.nio.charset.Charset`: Supports auto-completion of charset/encoding values (such as - `UTF-8`) +* Any `java.lang.Enum`: Lists the possible values for the property. + (We recommend defining the property with the `Enum` type, as no further hint should be required for the IDE to auto-complete the values) +* `java.nio.charset.Charset`: Supports auto-completion of charset/encoding values (such as `UTF-8`) * `java.util.Locale`: auto-completion of locales (such as `en_US`) -* `org.springframework.util.MimeType`: Supports auto-completion of content type values - (such as `text/plain`) -* `org.springframework.core.io.Resource`: Supports auto-completion of Spring’s Resource - abstraction to refer to a file on the filesystem or on the classpath. (such as - `classpath:/sample.properties`) +* `org.springframework.util.MimeType`: Supports auto-completion of content type values (such as `text/plain`) +* `org.springframework.core.io.Resource`: Supports auto-completion of Spring’s Resource abstraction to refer to a file on the filesystem or on the classpath (such as `classpath:/sample.properties`) -TIP: If multiple values can be provided, use a `Collection` or _Array_ type to teach the -IDE about it. +TIP: If multiple values can be provided, use a `Collection` or _Array_ type to teach the IDE about it. -The following metadata snippet corresponds to the standard `spring.liquibase.change-log` -property that defines the path to the changelog to use. It is actually used internally as a -`org.springframework.core.io.Resource` but cannot be exposed as such, because we need to -keep the original String value to pass it to the Liquibase API. +The following metadata snippet corresponds to the standard `spring.liquibase.change-log` property that defines the path to the changelog to use. +It is actually used internally as a `org.springframework.core.io.Resource` but cannot be exposed as such, because we need to keep the original String value to pass it to the Liquibase API. [source,json,indent=0] ---- @@ -597,33 +541,28 @@ keep the original String value to pass it to the Liquibase API. ===== Logger Name -The **logger-name** provider auto-completes valid logger names and -<>. Typically, -package and class names available in the current project can be auto-completed. If groups -are enabled (default) and if a custom logger group is identified in the configuration, -auto-completion for it should be provided. Specific frameworks may have extra magic logger -names that can be supported as well. +The **logger-name** provider auto-completes valid logger names and <>. +Typically, package and class names available in the current project can be auto-completed. +If groups are enabled (default) and if a custom logger group is identified in the configuration, auto-completion for it should be provided. +Specific frameworks may have extra magic logger names that can be supported as well. This provider supports the following parameters: [cols="1,1,2,4"] |=== -|Parameter |Type |Default value |Description +| Parameter | Type | Default value | Description -|`group` -|`boolean` -|`true` -|Specify whether known groups should be considered. +| `group` +| `boolean` +| `true` +| Specify whether known groups should be considered. |=== -Since a logger name can be any arbitrary name, this provider should allow any -value but could highlight valid package and class names that are not available in the -project's classpath. +Since a logger name can be any arbitrary name, this provider should allow any value but could highlight valid package and class names that are not available in the project's classpath. -The following metadata snippet corresponds to the standard `logging.level` property. Keys -are _logger names_, and values correspond to the standard log levels or any custom -level. As Spring Boot defines a few logger groups out-of-the-box, dedicated value hints -have been added for those. +The following metadata snippet corresponds to the standard `logging.level` property. +Keys are _logger names_, and values correspond to the standard log levels or any custom level. +As Spring Boot defines a few logger groups out-of-the-box, dedicated value hints have been added for those. [source,json,indent=0] ---- @@ -688,22 +627,21 @@ have been added for those. ===== Spring Bean Reference -The **spring-bean-reference** provider auto-completes the beans that are defined in -the configuration of the current project. This provider supports the following parameters: +The **spring-bean-reference** provider auto-completes the beans that are defined in the configuration of the current project. +This provider supports the following parameters: [cols="1,1,2,4"] |=== -|Parameter |Type |Default value |Description +| Parameter | Type | Default value | Description -|`target` +| `target` | `String` (`Class`) -|_none_ -|The fully qualified name of the bean class that should be assignable to the candidate. - Typically used to filter out non-candidate beans. +| _none_ +| The fully qualified name of the bean class that should be assignable to the candidate. + Typically used to filter out non-candidate beans. |=== -The following metadata snippet corresponds to the standard `spring.jmx.server` property -that defines the name of the `MBeanServer` bean to use: +The following metadata snippet corresponds to the standard `spring.jmx.server` property that defines the name of the `MBeanServer` bean to use: [source,json,indent=0] ---- @@ -722,17 +660,15 @@ that defines the name of the `MBeanServer` bean to use: ]} ---- -NOTE: The binder is not aware of the metadata. If you provide that hint, you still need -to transform the bean name into an actual Bean reference using by the `ApplicationContext`. +NOTE: The binder is not aware of the metadata. +If you provide that hint, you still need to transform the bean name into an actual Bean reference using by the `ApplicationContext`. ===== Spring Profile Name -The **spring-profile-name** provider auto-completes the Spring profiles that are -defined in the configuration of the current project. +The **spring-profile-name** provider auto-completes the Spring profiles that are defined in the configuration of the current project. -The following metadata snippet corresponds to the standard `spring.profiles.active` -property that defines the name of the Spring profile(s) to enable: +The following metadata snippet corresponds to the standard `spring.profiles.active` property that defines the name of the Spring profile(s) to enable: [source,json,indent=0] ---- @@ -752,14 +688,11 @@ property that defines the name of the Spring profile(s) to enable: [[configuration-metadata-annotation-processor]] === Generating Your Own Metadata by Using the Annotation Processor -You can easily generate your own configuration metadata file from items annotated with -`@ConfigurationProperties` by using the `spring-boot-configuration-processor` jar. -The jar includes a Java annotation processor which is invoked as your project is -compiled. To use the processor, include a dependency on -`spring-boot-configuration-processor`. +You can easily generate your own configuration metadata file from items annotated with `@ConfigurationProperties` by using the `spring-boot-configuration-processor` jar. +The jar includes a Java annotation processor which is invoked as your project is compiled. +To use the processor, include a dependency on `spring-boot-configuration-processor`. -With Maven the dependency should be declared as optional, as shown in the following -example: +With Maven the dependency should be declared as optional, as shown in the following example: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -770,8 +703,7 @@ example: ---- -With Gradle 4.5 and earlier, the dependency should be declared in the `compileOnly` -configuration, as shown in the following example: +With Gradle 4.5 and earlier, the dependency should be declared in the `compileOnly` configuration, as shown in the following example: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -780,8 +712,7 @@ configuration, as shown in the following example: } ---- -With Gradle 4.6 and later, the dependency should be declared in the `annotationProcessor` -configuration, as shown in the following example: +With Gradle 4.6 and later, the dependency should be declared in the `annotationProcessor` configuration, as shown in the following example: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -790,35 +721,26 @@ configuration, as shown in the following example: } ---- -If you are using an `additional-spring-configuration-metadata.json` file, the -`compileJava` task should be configured to depend on the `processResources` task, as shown -in the following example: +If you are using an `additional-spring-configuration-metadata.json` file, the `compileJava` task should be configured to depend on the `processResources` task, as shown in the following example: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- compileJava.dependsOn(processResources) ---- -This dependency ensures that the additional metadata is available when the annotation -processor runs during compilation. +This dependency ensures that the additional metadata is available when the annotation processor runs during compilation. -The processor picks up both classes and methods that are annotated with -`@ConfigurationProperties`. The Javadoc for field values within configuration classes -is used to populate the `description` attribute. +The processor picks up both classes and methods that are annotated with `@ConfigurationProperties`. +The Javadoc for field values within configuration classes is used to populate the `description` attribute. -NOTE: You should only use simple text with `@ConfigurationProperties` field Javadoc, since -they are not processed before being added to the JSON. +NOTE: You should only use simple text with `@ConfigurationProperties` field Javadoc, since they are not processed before being added to the JSON. -Properties are discovered through the presence of standard getters and setters with -special handling for collection types (that is detected even if only a getter is present). -The annotation processor also supports the use of the `@Data`, `@Getter`, and `@Setter` -lombok annotations. +Properties are discovered through the presence of standard getters and setters with special handling for collection types (that is detected even if only a getter is present). +The annotation processor also supports the use of the `@Data`, `@Getter`, and `@Setter` lombok annotations. -The annotation processor cannot auto-detect default values for ``Enum``s and -``Collections``s. In the cases where a `Collection` or `Enum` property has a non-empty -default value, <> should be -provided. +The annotation processor cannot auto-detect default values for ``Enum``s and ``Collections``s. +In the cases where a `Collection` or `Enum` property has a non-empty default value, <> should be provided. Consider the following class: @@ -836,7 +758,6 @@ Consider the following class: public enum ContainerType { SIMPLE, - DIRECT } @@ -844,9 +765,7 @@ Consider the following class: } ---- -In order to document default values for properties in the class above, you could add the -following content to <>: +In order to document default values for properties in the class above, you could add the following content to <>: [source,json,indent=0] ---- @@ -862,18 +781,14 @@ the module>>: ]} ---- -Only the `name` of the property is required to document additional fields with manual -metadata. - +Only the `name` of the property is required to document additional fields with manual metadata. [NOTE] ==== -If you are using AspectJ in your project, you need to make sure that the annotation -processor runs only once. There are several ways to do this. With Maven, you can -configure the `maven-apt-plugin` explicitly and add the dependency to the annotation -processor only there. You could also let the AspectJ plugin run all the processing -and disable annotation processing in the `maven-compiler-plugin` configuration, as -follows: +If you are using AspectJ in your project, you need to make sure that the annotation processor runs only once. +There are several ways to do this. +With Maven, you can configure the `maven-apt-plugin` explicitly and add the dependency to the annotation processor only there. +You could also let the AspectJ plugin run all the processing and disable annotation processing in the `maven-compiler-plugin` configuration, as follows: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -918,29 +833,22 @@ Consider the following class: } ---- -The preceding example produces metadata information for `server.name`, `server.host.ip`, -and `server.host.port` properties. You can use the `@NestedConfigurationProperty` -annotation on a field to indicate that a regular (non-inner) class should be treated as -if it were nested. +The preceding example produces metadata information for `server.name`, `server.host.ip`, and `server.host.port` properties. +You can use the `@NestedConfigurationProperty` annotation on a field to indicate that a regular (non-inner) class should be treated as if it were nested. + +TIP: This has no effect on collections and maps, as those types are automatically identified, and a single metadata property is generated for each of them. -TIP: This has no effect on collections and maps, as those types are automatically -identified, and a single metadata property is generated for each of them. [[configuration-metadata-additional-metadata]] ==== Adding Additional Metadata -Spring Boot's configuration file handling is quite flexible, and it is often the case -that properties may exist that are not bound to a `@ConfigurationProperties` bean. You -may also need to tune some attributes of an existing key. To support such cases and let -you provide custom "hints", the annotation processor automatically merges items -from `META-INF/additional-spring-configuration-metadata.json` into the main metadata -file. +Spring Boot's configuration file handling is quite flexible, and it is often the case that properties may exist that are not bound to a `@ConfigurationProperties` bean. +You may also need to tune some attributes of an existing key. +To support such cases and let you provide custom "hints", the annotation processor automatically merges items from `META-INF/additional-spring-configuration-metadata.json` into the main metadata file. -If you refer to a property that has been detected automatically, the description, -default value, and deprecation information are overridden, if specified. If the manual -property declaration is not identified in the current module, it is added as a new -property. +If you refer to a property that has been detected automatically, the description, default value, and deprecation information are overridden, if specified. +If the manual property declaration is not identified in the current module, it is added as a new property. -The format of the `additional-spring-configuration-metadata.json` file is exactly the same -as the regular `spring-configuration-metadata.json`. The additional properties file is -optional. If you do not have any additional properties, do not add the file. +The format of the `additional-spring-configuration-metadata.json` file is exactly the same as the regular `spring-configuration-metadata.json`. +The additional properties file is optional. +If you do not have any additional properties, do not add the file. diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-dependency-versions.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-dependency-versions.adoc index 8420cc301b2..75b397e1cf7 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-dependency-versions.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-dependency-versions.adoc @@ -1,9 +1,7 @@ [appendix] [[appendix-dependency-versions]] == Dependency versions -The following table provides details of all of the dependency versions that are provided -by Spring Boot in its CLI (Command Line Interface), Maven dependency management, and -Gradle plugin. When you declare a dependency on one of these artifacts without declaring -a version, the version listed in the table is used. +The following table provides details of all of the dependency versions that are provided by Spring Boot in its CLI (Command Line Interface), Maven dependency management, and Gradle plugin. +When you declare a dependency on one of these artifacts without declaring a version, the version listed in the table is used. -include::../../../target/generated-resources/effective-pom.adoc[] \ No newline at end of file +include::../../../target/generated-resources/effective-pom.adoc[] diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-executable-jar-format.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-executable-jar-format.adoc index fc153683444..46d6bbd355b 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-executable-jar-format.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-executable-jar-format.adoc @@ -1,29 +1,23 @@ [appendix] [[executable-jar]] == The Executable Jar Format -The `spring-boot-loader` modules lets Spring Boot support executable jar and -war files. If you use the Maven plugin or the Gradle plugin, executable jars are -automatically generated, and you generally do not need to know the details of how -they work. +The `spring-boot-loader` modules lets Spring Boot support executable jar and war files. +If you use the Maven plugin or the Gradle plugin, executable jars are automatically generated, and you generally do not need to know the details of how they work. -If you need to create executable jars from a different build system or if you are just -curious about the underlying technology, this section provides some background. +If you need to create executable jars from a different build system or if you are just curious about the underlying technology, this section provides some background. [[executable-jar-nested-jars]] === Nested JARs -Java does not provide any standard way to load nested jar files (that is, jar files that -are themselves contained within a jar). This can be problematic if you need -to distribute a self-contained application that can be run from the command line -without unpacking. +Java does not provide any standard way to load nested jar files (that is, jar files that are themselves contained within a jar). +This can be problematic if you need to distribute a self-contained application that can be run from the command line without unpacking. -To solve this problem, many developers use "`shaded`" jars. A shaded jar packages -all classes, from all jars, into a single "`uber jar`". The problem with shaded jars is -that it becomes hard to see which libraries are actually in your application. -It can also be problematic if the same filename is used (but with different content) -in multiple jars. Spring Boot takes a different approach and lets you actually nest -jars directly. +To solve this problem, many developers use "`shaded`" jars. +A shaded jar packages all classes, from all jars, into a single "`uber jar`". +The problem with shaded jars is that it becomes hard to see which libraries are actually in your application. +It can also be problematic if the same filename is used (but with different content) in multiple jars. +Spring Boot takes a different approach and lets you actually nest jars directly. @@ -86,19 +80,16 @@ Spring Boot Loader-compatible war files should be structured in the following wa +-dependency3.jar ---- -Dependencies should be placed in a nested `WEB-INF/lib` directory. Any dependencies -that are required when running embedded but are not required when deploying to -a traditional web container should be placed in `WEB-INF/lib-provided`. +Dependencies should be placed in a nested `WEB-INF/lib` directory. +Any dependencies that are required when running embedded but are not required when deploying to a traditional web container should be placed in `WEB-INF/lib-provided`. [[executable-jar-jarfile]] === Spring Boot's "`JarFile`" Class -The core class used to support loading nested jars is -`org.springframework.boot.loader.jar.JarFile`. It lets you load jar -content from a standard jar file or from nested child jar data. When first loaded, the -location of each `JarEntry` is mapped to a physical file offset of the outer jar, as -shown in the following example: +The core class used to support loading nested jars is `org.springframework.boot.loader.jar.JarFile`. +It lets you load jar content from a standard jar file or from nested child jar data. +When first loaded, the location of each `JarEntry` is mapped to a physical file offset of the outer jar, as shown in the following example: [indent=0] ---- @@ -113,52 +104,41 @@ shown in the following example: 0063 3452 3980 ---- -The preceding example shows how `A.class` can be found in `/BOOT-INF/classes` in -`myapp.jar` at position `0063`. `B.class` from the nested jar can actually be found in -`myapp.jar` at position `3452`, and `C.class` is at position `3980`. +The preceding example shows how `A.class` can be found in `/BOOT-INF/classes` in `myapp.jar` at position `0063`. +`B.class` from the nested jar can actually be found in `myapp.jar` at position `3452`, and `C.class` is at position `3980`. -Armed with this information, we can load specific nested entries by seeking to -the appropriate part of the outer jar. We do not need to unpack the archive, and we -do not need to read all entry data into memory. +Armed with this information, we can load specific nested entries by seeking to the appropriate part of the outer jar. +We do not need to unpack the archive, and we do not need to read all entry data into memory. [[executable-jar-jarfile-compatibility]] ==== Compatibility with the Standard Java "`JarFile`" Spring Boot Loader strives to remain compatible with existing code and libraries. -`org.springframework.boot.loader.jar.JarFile` extends from `java.util.jar.JarFile` and -should work as a drop-in replacement. The `getURL()` method returns a `URL` that -opens a connection compatible with `java.net.JarURLConnection` and can be used with Java's -`URLClassLoader`. +`org.springframework.boot.loader.jar.JarFile` extends from `java.util.jar.JarFile` and should work as a drop-in replacement. +The `getURL()` method returns a `URL` that opens a connection compatible with `java.net.JarURLConnection` and can be used with Java's `URLClassLoader`. [[executable-jar-launching]] === Launching Executable Jars -The `org.springframework.boot.loader.Launcher` class is a special bootstrap class that -is used as an executable jar's main entry point. It is the actual `Main-Class` in your jar -file, and it is used to setup an appropriate `URLClassLoader` and ultimately call your -`main()` method. +The `org.springframework.boot.loader.Launcher` class is a special bootstrap class that is used as an executable jar's main entry point. +It is the actual `Main-Class` in your jar file, and it is used to setup an appropriate `URLClassLoader` and ultimately call your `main()` method. -There are three launcher subclasses (`JarLauncher`, `WarLauncher`, and -`PropertiesLauncher`). Their purpose is to load resources (`.class` files and so on.) from -nested jar files or war files in directories (as opposed to those explicitly on the -classpath). In the case of `JarLauncher` and `WarLauncher`, the nested paths are fixed. -`JarLauncher` looks in `BOOT-INF/lib/`, and `WarLauncher` looks in `WEB-INF/lib/` and -`WEB-INF/lib-provided/`. You can add extra jars in those locations if you want more. The -`PropertiesLauncher` looks in `BOOT-INF/lib/` in your application archive by default, but -you can add additional locations by setting an environment variable called `LOADER_PATH` -or `loader.path` in `loader.properties` (which is a comma-separated list of directories, -archives, or directories within archives). +There are three launcher subclasses (`JarLauncher`, `WarLauncher`, and `PropertiesLauncher`). +Their purpose is to load resources (`.class` files and so on) from nested jar files or war files in directories (as opposed to those explicitly on the classpath). +In the case of `JarLauncher` and `WarLauncher`, the nested paths are fixed. +`JarLauncher` looks in `BOOT-INF/lib/`, and `WarLauncher` looks in `WEB-INF/lib/` and `WEB-INF/lib-provided/`. +You can add extra jars in those locations if you want more. +The `PropertiesLauncher` looks in `BOOT-INF/lib/` in your application archive by default. +You can add additional locations by setting an environment variable called `LOADER_PATH` or `loader.path` in `loader.properties` (which is a comma-separated list of directories, archives, or directories within archives). [[executable-jar-launcher-manifest]] ==== Launcher Manifest -You need to specify an appropriate `Launcher` as the `Main-Class` attribute of -`META-INF/MANIFEST.MF`. The actual class that you want to launch (that is, the class that -contains a `main` method) should be specified in the `Start-Class` -attribute. +You need to specify an appropriate `Launcher` as the `Main-Class` attribute of `META-INF/MANIFEST.MF`. +The actual class that you want to launch (that is, the class that contains a `main` method) should be specified in the `Start-Class` attribute. The following example shows a typical `MANIFEST.MF` for an executable jar file: @@ -176,16 +156,16 @@ For a war file, it would be as follows: Start-Class: com.mycompany.project.MyApplication ---- -NOTE: You need not specify `Class-Path` entries in your manifest file. The classpath -is deduced from the nested jars. +NOTE: You need not specify `Class-Path` entries in your manifest file. +The classpath is deduced from the nested jars. [[executable-jar-exploded-archives]] ==== Exploded Archives -Certain PaaS implementations may choose to unpack archives before they run. For example, -Cloud Foundry operates this way. You can run an unpacked archive by starting -the appropriate launcher, as follows: +Certain PaaS implementations may choose to unpack archives before they run. +For example, Cloud Foundry operates this way. +You can run an unpacked archive by starting the appropriate launcher, as follows: [indent=0] ---- @@ -197,136 +177,114 @@ the appropriate launcher, as follows: [[executable-jar-property-launcher-features]] === `PropertiesLauncher` Features - -`PropertiesLauncher` has a few special features that can be enabled with external -properties (System properties, environment variables, manifest entries, or -`loader.properties`). The following table describes these properties: +`PropertiesLauncher` has a few special features that can be enabled with external properties (System properties, environment variables, manifest entries, or `loader.properties`). +The following table describes these properties: |=== -|Key |Purpose +| Key | Purpose -|`loader.path` -|Comma-separated Classpath, such as `lib,$\{HOME}/app/lib`. Earlier entries take - precedence, like a regular `-classpath` on the `javac` command line. +| `loader.path` +| Comma-separated Classpath, such as `lib,$\{HOME}/app/lib`. + Earlier entries take precedence, like a regular `-classpath` on the `javac` command line. -|`loader.home` -|Used to resolve relative paths in `loader.path`. For example, given `loader.path=lib`, - then `${loader.home}/lib` is a classpath location (along with all jar files in that - directory). This property is also used to locate a `loader.properties` file, as in the - following example `file:///opt/app` - It defaults to `${user.dir}`. +| `loader.home` +| Used to resolve relative paths in `loader.path`. + For example, given `loader.path=lib`, then `${loader.home}/lib` is a classpath location (along with all jar files in that directory). + This property is also used to locate a `loader.properties` file, as in the following example `file:///opt/app` It defaults to `${user.dir}`. -|`loader.args` -|Default arguments for the main method (space separated). +| `loader.args` +| Default arguments for the main method (space separated). -|`loader.main` -|Name of main class to launch (for example, `com.app.Application`). +| `loader.main` +| Name of main class to launch (for example, `com.app.Application`). -|`loader.config.name` -|Name of properties file (for example, `launcher`) It defaults to `loader`. +| `loader.config.name` +| Name of properties file (for example, `launcher`). + It defaults to `loader`. -|`loader.config.location` -|Path to properties file (for example, `classpath:loader.properties`). It defaults to - `loader.properties`. - -|`loader.system` -|Boolean flag to indicate that all properties should be added to System properties - It defaults to `false`. +| `loader.config.location` +| Path to properties file (for example, `classpath:loader.properties`). + It defaults to `loader.properties`. +| `loader.system` +| Boolean flag to indicate that all properties should be added to System properties. + It defaults to `false`. |=== -When specified as environment variables or manifest entries, the following names should -be used: +When specified as environment variables or manifest entries, the following names should be used: |=== -|Key | Manifest entry | Environment variable +| Key | Manifest entry | Environment variable -|`loader.path` -|`Loader-Path` -|`LOADER_PATH` +| `loader.path` +| `Loader-Path` +| `LOADER_PATH` -|`loader.home` -|`Loader-Home` -|`LOADER_HOME` +| `loader.home` +| `Loader-Home` +| `LOADER_HOME` -|`loader.args` -|`Loader-Args` -|`LOADER_ARGS` +| `loader.args` +| `Loader-Args` +| `LOADER_ARGS` -|`loader.main` -|`Start-Class` -|`LOADER_MAIN` +| `loader.main` +| `Start-Class` +| `LOADER_MAIN` -|`loader.config.location` -|`Loader-Config-Location` -|`LOADER_CONFIG_LOCATION` - -|`loader.system` -|`Loader-System` -|`LOADER_SYSTEM` +| `loader.config.location` +| `Loader-Config-Location` +| `LOADER_CONFIG_LOCATION` +| `loader.system` +| `Loader-System` +| `LOADER_SYSTEM` |=== -TIP: Build plugins automatically move the `Main-Class` attribute to `Start-Class` when -the fat jar is built. If you use that, specify the name of the class to launch by using -the `Main-Class` attribute and leaving out `Start-Class`. +TIP: Build plugins automatically move the `Main-Class` attribute to `Start-Class` when the fat jar is built. +If you use that, specify the name of the class to launch by using the `Main-Class` attribute and leaving out `Start-Class`. The following rules apply to working with `PropertiesLauncher`: -* `loader.properties` is searched for in `loader.home`, then in the root of the - classpath, and then in `classpath:/BOOT-INF/classes`. The first location where a file - with that name exists is used. -* `loader.home` is the directory location of an additional properties file - (overriding the default) only when `loader.config.location` is not specified. -* `loader.path` can contain directories (which are scanned recursively for jar and zip - files), archive paths, a directory within an archive that is scanned for jar files (for - example, `dependencies.jar!/lib`), or wildcard patterns (for the default JVM behavior). - Archive paths can be relative to `loader.home` or anywhere in the file system with a - `jar:file:` prefix. -* `loader.path` (if empty) defaults to `BOOT-INF/lib` (meaning a local directory or a - nested one if running from an archive). Because of this, `PropertiesLauncher` behaves - the same as `JarLauncher` when no additional configuration is provided. -* `loader.path` can not be used to configure the location of `loader.properties` (the - classpath used to search for the latter is the JVM classpath when `PropertiesLauncher` - is launched). -* Placeholder replacement is done from System and environment variables plus the - properties file itself on all values before use. -* The search order for properties (where it makes sense to look in more than one place) - is environment variables, system properties, `loader.properties`, the exploded archive - manifest, and the archive manifest. +* `loader.properties` is searched for in `loader.home`, then in the root of the classpath, and then in `classpath:/BOOT-INF/classes`. + The first location where a file with that name exists is used. +* `loader.home` is the directory location of an additional properties file (overriding the default) only when `loader.config.location` is not specified. +* `loader.path` can contain directories (which are scanned recursively for jar and zip files), archive paths, a directory within an archive that is scanned for jar files (for example, `dependencies.jar!/lib`), or wildcard patterns (for the default JVM behavior). + Archive paths can be relative to `loader.home` or anywhere in the file system with a `jar:file:` prefix. +* `loader.path` (if empty) defaults to `BOOT-INF/lib` (meaning a local directory or a nested one if running from an archive). + Because of this, `PropertiesLauncher` behaves the same as `JarLauncher` when no additional configuration is provided. +* `loader.path` can not be used to configure the location of `loader.properties` (the classpath used to search for the latter is the JVM classpath when `PropertiesLauncher` is launched). +* Placeholder replacement is done from System and environment variables plus the properties file itself on all values before use. +* The search order for properties (where it makes sense to look in more than one place) is environment variables, system properties, `loader.properties`, the exploded archive manifest, and the archive manifest. [[executable-jar-restrictions]] === Executable Jar Restrictions -You need to consider the following restrictions when working with a Spring -Boot Loader packaged application: +You need to consider the following restrictions when working with a Spring Boot Loader packaged application: [[executable-jar-zip-entry-compression]] * Zip entry compression: -The `ZipEntry` for a nested jar must be saved by using the `ZipEntry.STORED` method. This -is required so that we can seek directly to individual content within the nested jar. -The content of the nested jar file itself can still be compressed, as can any other -entries in the outer jar. +The `ZipEntry` for a nested jar must be saved by using the `ZipEntry.STORED` method. +This is required so that we can seek directly to individual content within the nested jar. +The content of the nested jar file itself can still be compressed, as can any other entries in the outer jar. [[executable-jar-system-classloader]] * System classLoader: -Launched applications should use `Thread.getContextClassLoader()` when loading classes -(most libraries and frameworks do so by default). Trying to load nested jar -classes with `ClassLoader.getSystemClassLoader()` fails. -`java.util.Logging` always uses the system classloader. For this reason, you should -consider a different logging implementation. +Launched applications should use `Thread.getContextClassLoader()` when loading classes (most libraries and frameworks do so by default). +Trying to load nested jar classes with `ClassLoader.getSystemClassLoader()` fails. +`java.util.Logging` always uses the system classloader. +For this reason, you should consider a different logging implementation. [[executable-jar-alternatives]] === Alternative Single Jar Solutions -If the preceding restrictions mean that you cannot use Spring Boot Loader, consider the -following alternatives: +If the preceding restrictions mean that you cannot use Spring Boot Loader, consider the following alternatives: * https://maven.apache.org/plugins/maven-shade-plugin/[Maven Shade Plugin] * http://www.jdotsoft.com/JarClassLoader.php[JarClassLoader] diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-test-auto-configuration.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-test-auto-configuration.adoc index 9fe14819d67..43d41c36811 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-test-auto-configuration.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-test-auto-configuration.adoc @@ -1,7 +1,6 @@ [appendix] [[test-auto-configuration]] == Test auto-configuration annotations -The following table lists the various `@…Test` annotations that can be used to test -slices of your application and the auto-configuration that they import by default: +The following table lists the various `@…Test` annotations that can be used to test slices of your application and the auto-configuration that they import by default: -include::../../../target/generated-resources/test-slice-auto-configuration.adoc[] \ No newline at end of file +include::../../../target/generated-resources/test-slice-auto-configuration.adoc[] diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/build-tool-plugins.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/build-tool-plugins.adoc index 05969b3c2e7..a2526e297f3 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/build-tool-plugins.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/build-tool-plugins.adoc @@ -3,31 +3,25 @@ [partintro] -- -Spring Boot provides build tool plugins for Maven and Gradle. The plugins offer a variety -of features, including the packaging of executable jars. This section provides more -details on both plugins as well as some help should you need to extend an unsupported -build system. If you are just getting started, you might want to read -"`<>`" from the -"`<>`" section first. +Spring Boot provides build tool plugins for Maven and Gradle. The plugins offer a variety of features, including the packaging of executable jars. +This section provides more details on both plugins as well as some help should you need to extend an unsupported build system. +If you are just getting started, you might want to read "`<>`" from the "`<>`" section first. -- [[build-tool-plugins-maven-plugin]] == Spring Boot Maven Plugin -The {spring-boot-maven-plugin-site}[Spring Boot Maven Plugin] provides Spring Boot -support in Maven, letting you package executable jar or war archives and run an -application "`in-place`". To use it, you must use Maven 3.2 (or later). +The {spring-boot-maven-plugin-site}[Spring Boot Maven Plugin] provides Spring Boot support in Maven, letting you package executable jar or war archives and run an application "`in-place`". +To use it, you must use Maven 3.2 (or later). -NOTE: See the {spring-boot-maven-plugin-site}[Spring Boot Maven Plugin Site] for complete -plugin documentation. +NOTE: See the {spring-boot-maven-plugin-site}[Spring Boot Maven Plugin Site] for complete plugin documentation. [[build-tool-plugins-include-maven-plugin]] === Including the Plugin -To use the Spring Boot Maven Plugin, include the appropriate XML in the `plugins` -section of your `pom.xml`, as shown in the following example: +To use the Spring Boot Maven Plugin, include the appropriate XML in the `plugins` section of your `pom.xml`, as shown in the following example: [source,xml,indent=0,subs="verbatim,attributes"] ---- @@ -55,9 +49,8 @@ section of your `pom.xml`, as shown in the following example: ---- -The preceding configuration repackages a jar or war that is built during the `package` -phase of the Maven lifecycle. The following example shows both the repackaged jar as well -as the original jar in the `target` directory: +The preceding configuration repackages a jar or war that is built during the `package` phase of the Maven lifecycle. +The following example shows both the repackaged jar as well as the original jar in the `target` directory: [indent=0] ---- @@ -67,9 +60,7 @@ as the original jar in the `target` directory: ---- -If you do not include the `` configuration, as shown in the prior example, you -can run the plugin on its own (but only if the package goal is used as well), as shown in -the following example: +If you do not include the `` configuration, as shown in the prior example, you can run the plugin on its own (but only if the package goal is used as well), as shown in the following example: [indent=0] ---- @@ -78,8 +69,7 @@ the following example: target/myproject-1.0.0.jar target/myproject-1.0.0.jar.original ---- -If you use a milestone or snapshot release, you also need to add the appropriate -`pluginRepository` elements, as shown in the following listing: +If you use a milestone or snapshot release, you also need to add the appropriate `pluginRepository` elements, as shown in the following listing: [source,xml,indent=0,subs="verbatim,attributes"] ---- @@ -99,10 +89,8 @@ If you use a milestone or snapshot release, you also need to add the appropriate [[build-tool-plugins-maven-packaging]] === Packaging Executable Jar and War Files -Once `spring-boot-maven-plugin` has been included in your `pom.xml`, it automatically -tries to rewrite archives to make them executable by using the `spring-boot:repackage` -goal. You should configure your project to build a jar or war (as appropriate) by using -the usual `packaging` element, as shown in the following example: +Once `spring-boot-maven-plugin` has been included in your `pom.xml`, it automatically tries to rewrite archives to make them executable by using the `spring-boot:repackage` goal. +You should configure your project to build a jar or war (as appropriate) by using the usual `packaging` element, as shown in the following example: [source,xml,indent=0,subs="verbatim,attributes"] ---- @@ -115,11 +103,10 @@ the usual `packaging` element, as shown in the following example: ---- -Your existing archive is enhanced by Spring Boot during the `package` phase. The main -class that you want to launch can be specified either by using a configuration option, as -shown below, or by adding a `Main-Class` attribute to the manifest. If you do not specify -a main class, the plugin searches for a class with a `public static void main(String[] args)` -method. +Your existing archive is enhanced by Spring Boot during the `package` phase. +The main class that you want to launch can be specified either by using a configuration option, as shown below, or by adding a `Main-Class` attribute to the manifest. +If you do not specify a main class, the plugin searches for a class with a `public static void main(String[] args)` method. + [source,xml,indent=0,subs="verbatim,attributes"] ---- @@ -140,9 +127,7 @@ To build and run a project artifact, you can type the following: $ java -jar target/mymodule-0.0.1-SNAPSHOT.jar ---- -To build a war file that is both executable and deployable into an external container, you -need to mark the embedded container dependencies as "`provided`", as shown in the -following example: +To build a war file that is both executable and deployable into an external container, you need to mark the embedded container dependencies as "`provided`", as shown in the following example: [source,xml,indent=0,subs="verbatim,attributes"] ---- @@ -167,32 +152,28 @@ following example: ---- -TIP: See the "`<>`" section for more details on how to -create a deployable war file. +TIP: See the "`<>`" section for more details on how to create a deployable war file. -Advanced configuration options and examples are available in the -{spring-boot-maven-plugin-site}[plugin info page]. +Advanced configuration options and examples are available in the {spring-boot-maven-plugin-site}[plugin info page]. [[build-tool-plugins-gradle-plugin]] == Spring Boot Gradle Plugin -The Spring Boot Gradle Plugin provides Spring Boot support in Gradle, letting you package -executable jar or war archives, run Spring Boot applications, and use the dependency -management provided by `spring-boot-dependencies`. It requires Gradle 4.4 or later. Please -refer to the plugin's documentation to learn more: +The Spring Boot Gradle Plugin provides Spring Boot support in Gradle, letting you package executable jar or war archives, run Spring Boot applications, and use the dependency management provided by `spring-boot-dependencies`. +It requires Gradle 4.4 or later. +Please refer to the plugin's documentation to learn more: -* Reference ({spring-boot-gradle-plugin}/reference/html[HTML] and - {spring-boot-gradle-plugin}/reference/pdf/spring-boot-gradle-plugin-reference.pdf[PDF]) +* Reference ({spring-boot-gradle-plugin}/reference/html[HTML] and {spring-boot-gradle-plugin}/reference/pdf/spring-boot-gradle-plugin-reference.pdf[PDF]) * {spring-boot-gradle-plugin}/api[API] [[build-tool-plugins-antlib]] == Spring Boot AntLib Module -The Spring Boot AntLib module provides basic Spring Boot support for Apache Ant. You can -use the module to create executable jars. To use the module, you need to declare an -additional `spring-boot` namespace in your `build.xml`, as shown in the following example: +The Spring Boot AntLib module provides basic Spring Boot support for Apache Ant. +You can use the module to create executable jars. +To use the module, you need to declare an additional `spring-boot` namespace in your `build.xml`, as shown in the following example: [source,xml,indent=0] ---- @@ -203,68 +184,66 @@ additional `spring-boot` namespace in your `build.xml`, as shown in the followin ---- -You need to remember to start Ant using the `-lib` option, as shown in the following -example: +You need to remember to start Ant using the `-lib` option, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- $ ant -lib ---- -TIP: The "`Using Spring Boot`" section includes a more complete example of -<>. +TIP: The "`Using Spring Boot`" section includes a more complete example of <>. + +[[spring-boot-ant-tasks]] === Spring Boot Ant Tasks -Once the `spring-boot-antlib` namespace has been declared, the following additional tasks -are available: +Once the `spring-boot-antlib` namespace has been declared, the following additional tasks are available: * <> * <> + + [[spring-boot-ant-exejar]] ==== `spring-boot:exejar` -You can use the `exejar` task to create a Spring Boot executable jar. The following -attributes are supported by the task: +You can use the `exejar` task to create a Spring Boot executable jar. +The following attributes are supported by the task: [cols="1,2,2"] |==== -|Attribute |Description |Required +| Attribute | Description | Required -|`destfile` -|The destination jar file to create -|Yes +| `destfile` +| The destination jar file to create +| Yes -|`classes` -|The root directory of Java class files -|Yes +| `classes` +| The root directory of Java class files +| Yes -|`start-class` -|The main application class to run -|No _(the default is the first class found that declares a `main` method)_ +| `start-class` +| The main application class to run +| No _(the default is the first class found that declares a `main` method)_ |==== The following nested elements can be used with the task: [cols="1,4"] |==== -|Element |Description +| Element | Description -|`resources` -|One or more {ant-manual}/Types/resources.html#collection[Resource Collections] describing -a set of {ant-manual}/Types/resources.html[Resources] that should be added to the content -of the created +jar+ file. +| `resources` +| One or more {ant-manual}/Types/resources.html#collection[Resource Collections] describing a set of {ant-manual}/Types/resources.html[Resources] that should be added to the content of the created +jar+ file. -|`lib` -|One or more {ant-manual}/Types/resources.html#collection[Resource Collections] that -should be added to the set of jar libraries that make up the runtime dependency classpath -of the application. +| `lib` +| One or more {ant-manual}/Types/resources.html#collection[Resource Collections] that should be added to the set of jar libraries that make up the runtime dependency classpath of the application. |==== -==== Examples +[[spring-boot-ant-exejar-examples]] +==== Examples This section shows two examples of Ant tasks. .Specify +start-class+ @@ -292,33 +271,34 @@ This section shows two examples of Ant tasks. ---- + [[spring-boot-ant-findmainclass]] === `spring-boot:findmainclass` -The `findmainclass` task is used internally by `exejar` to locate a class declaring a -`main`. If necessary, you can also use this task directly in your build. The following -attributes are supported: +The `findmainclass` task is used internally by `exejar` to locate a class declaring a `main`. +If necessary, you can also use this task directly in your build. +The following attributes are supported: [cols="1,2,2"] |==== -|Attribute |Description |Required +| Attribute | Description | Required -|`classesroot` -|The root directory of Java class files -|Yes _(unless `mainclass` is specified)_ +| `classesroot` +| The root directory of Java class files +| Yes _(unless `mainclass` is specified)_ -|`mainclass` -|Can be used to short-circuit the `main` class search -|No +| `mainclass` +| Can be used to short-circuit the `main` class search +| No -|`property` -|The Ant property that should be set with the result -|No _(result will be logged if unspecified)_ +| `property` +| The Ant property that should be set with the result +| No _(result will be logged if unspecified)_ |==== +[[spring-boot-ant-findmainclass-examples]] ==== Examples - This section contains three examples of using `findmainclass`. .Find and log @@ -343,32 +323,27 @@ This section contains three examples of using `findmainclass`. [[build-tool-plugins-other-build-systems]] == Supporting Other Build Systems -If you want to use a build tool other than Maven, Gradle, or Ant, you likely need to -develop your own plugin. Executable jars need to follow a specific format and certain -entries need to be written in an uncompressed form (see the -"`<>`" section -in the appendix for details). +If you want to use a build tool other than Maven, Gradle, or Ant, you likely need to develop your own plugin. +Executable jars need to follow a specific format and certain entries need to be written in an uncompressed form (see the "`<>`" section in the appendix for details). -The Spring Boot Maven and Gradle plugins both make use of `spring-boot-loader-tools` to -actually generate jars. If you need to, you may use this library directly. +The Spring Boot Maven and Gradle plugins both make use of `spring-boot-loader-tools` to actually generate jars. +If you need to, you may use this library directly. [[build-tool-plugins-repackaging-archives]] === Repackaging Archives -To repackage an existing archive so that it becomes a self-contained executable archive, -use `org.springframework.boot.loader.tools.Repackager`. The `Repackager` class takes a -single constructor argument that refers to an existing jar or war archive. Use one of the -two available `repackage()` methods to either replace the original file or write to a new -destination. Various settings can also be configured on the repackager before it is run. +To repackage an existing archive so that it becomes a self-contained executable archive, use `org.springframework.boot.loader.tools.Repackager`. +The `Repackager` class takes a single constructor argument that refers to an existing jar or war archive. +Use one of the two available `repackage()` methods to either replace the original file or write to a new destination. +Various settings can also be configured on the repackager before it is run. [[build-tool-plugins-nested-libraries]] === Nested Libraries -When repackaging an archive, you can include references to dependency files by using the -`org.springframework.boot.loader.tools.Libraries` interface. We do not provide any -concrete implementations of `Libraries` here as they are usually build-system-specific. +When repackaging an archive, you can include references to dependency files by using the `org.springframework.boot.loader.tools.Libraries` interface. +We do not provide any concrete implementations of `Libraries` here as they are usually build-system-specific. If your archive already includes libraries, you can use `Libraries.NONE`. @@ -376,10 +351,8 @@ If your archive already includes libraries, you can use `Libraries.NONE`. [[build-tool-plugins-find-a-main-class]] === Finding a Main Class -If you do not use `Repackager.setMainClass()` to specify a main class, the repackager -uses https://asm.ow2.org/[ASM] to read class files and tries to find a suitable class with -a `public static void main(String[] args)` method. An exception is thrown if more than one -candidate is found. +If you do not use `Repackager.setMainClass()` to specify a main class, the repackager uses https://asm.ow2.org/[ASM] to read class files and tries to find a suitable class with a `public static void main(String[] args)` method. +An exception is thrown if more than one candidate is found. @@ -404,10 +377,7 @@ The following example shows a typical repackage implementation: [[build-tool-plugins-whats-next]] == What to Read Next -If you are interested in how the build tool plugins work, you can -look at the {github-code}/spring-boot-project/spring-boot-tools[`spring-boot-tools`] -module on GitHub. More technical details of the executable jar format are covered in -<>. +If you are interested in how the build tool plugins work, you can look at the {github-code}/spring-boot-project/spring-boot-tools[`spring-boot-tools`] module on GitHub. +More technical details of the executable jar format are covered in <>. -If you have specific build-related questions, you can check out the -"`<>`" guides. +If you have specific build-related questions, you can check out the "`<>`" guides. diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/deployment.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/deployment.adoc index 154fa1e279a..4eeaa2a6cc2 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/deployment.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/deployment.adoc @@ -3,9 +3,8 @@ [partintro] -- -Spring Boot's flexible packaging options provide a great deal of choice when it comes to -deploying your application. You can deploy Spring Boot applications to a variety -of cloud platforms, to container images (such as Docker), or to virtual/real machines. +Spring Boot's flexible packaging options provide a great deal of choice when it comes to deploying your application. +You can deploy Spring Boot applications to a variety of cloud platforms, to container images (such as Docker), or to virtual/real machines. This section covers some of the more common deployment scenarios. -- @@ -14,60 +13,44 @@ This section covers some of the more common deployment scenarios. [[cloud-deployment]] == Deploying to the Cloud -Spring Boot's executable jars are ready-made for most popular cloud PaaS -(Platform-as-a-Service) providers. These providers tend to require that you -"`bring your own container`". They manage application processes (not Java applications -specifically), so they need an intermediary layer that adapts _your_ application to the -_cloud's_ notion of a running process. +Spring Boot's executable jars are ready-made for most popular cloud PaaS (Platform-as-a-Service) providers. +These providers tend to require that you "`bring your own container`". +They manage application processes (not Java applications specifically), so they need an intermediary layer that adapts _your_ application to the _cloud's_ notion of a running process. Two popular cloud providers, Heroku and Cloud Foundry, employ a "`buildpack`" approach. The buildpack wraps your deployed code in whatever is needed to _start_ your application. -It might be a JDK and a call to `java`, an embedded web server, or a full-fledged -application server. A buildpack is pluggable, but ideally you should be able to get by -with as few customizations to it as possible. This reduces the footprint of functionality -that is not under your control. It minimizes divergence between development and production -environments. +It might be a JDK and a call to `java`, an embedded web server, or a full-fledged application server. +A buildpack is pluggable, but ideally you should be able to get by with as few customizations to it as possible. +This reduces the footprint of functionality that is not under your control. +It minimizes divergence between development and production environments. -Ideally, your application, like a Spring Boot executable jar, has everything that it needs -to run packaged within it. +Ideally, your application, like a Spring Boot executable jar, has everything that it needs to run packaged within it. -In this section, we look at what it takes to get the -<> in the "`Getting Started`" section up and running in the Cloud. +In this section, we look at what it takes to get the <> in the "`Getting Started`" section up and running in the Cloud. [[cloud-deployment-cloud-foundry]] === Cloud Foundry -Cloud Foundry provides default buildpacks that come into play if no other buildpack is -specified. The Cloud Foundry https://github.com/cloudfoundry/java-buildpack[Java -buildpack] has excellent support for Spring applications, including Spring Boot. You can -deploy stand-alone executable jar applications as well as traditional `.war` packaged -applications. +Cloud Foundry provides default buildpacks that come into play if no other buildpack is specified. +The Cloud Foundry https://github.com/cloudfoundry/java-buildpack[Java buildpack] has excellent support for Spring applications, including Spring Boot. +You can deploy stand-alone executable jar applications as well as traditional `.war` packaged applications. -Once you have built your application (by using, for example, `mvn clean package`) and have -https://docs.cloudfoundry.org/cf-cli/install-go-cli.html[installed the `cf` -command line tool], deploy your application by using the `cf push` command, substituting -the path to your compiled `.jar`. Be sure to have -https://docs.cloudfoundry.org/cf-cli/getting-started.html#login[logged in with -your `cf` command line client] before pushing an application. The following line shows -using the `cf push` command to deploy an application: +Once you have built your application (by using, for example, `mvn clean package`) and have https://docs.cloudfoundry.org/cf-cli/install-go-cli.html[installed the `cf` command line tool], deploy your application by using the `cf push` command, substituting the path to your compiled `.jar`. +Be sure to have https://docs.cloudfoundry.org/cf-cli/getting-started.html#login[logged in with your `cf` command line client] before pushing an application. +The following line shows using the `cf push` command to deploy an application: [indent=0,subs="verbatim,quotes,attributes"] ---- $ cf push acloudyspringtime -p target/demo-0.0.1-SNAPSHOT.jar ---- -NOTE: In the preceding example, we substitute `acloudyspringtime` for whatever value you -give `cf` as the name of your application. +NOTE: In the preceding example, we substitute `acloudyspringtime` for whatever value you give `cf` as the name of your application. -See the https://docs.cloudfoundry.org/cf-cli/getting-started.html#push[`cf push` -documentation] for more options. If there is a Cloud Foundry -https://docs.cloudfoundry.org/devguide/deploy-apps/manifest.html[`manifest.yml`] -file present in the same directory, it is considered. +See the https://docs.cloudfoundry.org/cf-cli/getting-started.html#push[`cf push` documentation] for more options. +If there is a Cloud Foundry https://docs.cloudfoundry.org/devguide/deploy-apps/manifest.html[`manifest.yml`] file present in the same directory, it is considered. -At this point, `cf` starts uploading your application, producing output similar to the -following example: +At this point, `cf` starts uploading your application, producing output similar to the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -96,8 +79,7 @@ following example: Congratulations! The application is now live! -Once your application is live, you can verify the status of the deployed application by -using the `cf apps` command, as shown in the following example: +Once your application is live, you can verify the status of the deployed application by using the `cf apps` command, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -111,23 +93,18 @@ using the `cf apps` command, as shown in the following example: ... ---- -Once Cloud Foundry acknowledges that your application has been deployed, you should be -able to find the application at the URI given. In the preceding example, you could find -it at `\https://acloudyspringtime.cfapps.io/`. +Once Cloud Foundry acknowledges that your application has been deployed, you should be able to find the application at the URI given. +In the preceding example, you could find it at `\https://acloudyspringtime.cfapps.io/`. [[cloud-deployment-cloud-foundry-services]] ==== Binding to Services -By default, metadata about the running application as well as service connection -information is exposed to the application as environment variables (for example: -`$VCAP_SERVICES`). This architecture decision is due to Cloud Foundry's polyglot (any -language and platform can be supported as a buildpack) nature. Process-scoped environment -variables are language agnostic. +By default, metadata about the running application as well as service connection information is exposed to the application as environment variables (for example: `$VCAP_SERVICES`). +This architecture decision is due to Cloud Foundry's polyglot (any language and platform can be supported as a buildpack) nature. +Process-scoped environment variables are language agnostic. -Environment variables do not always make for the easiest API, so Spring Boot automatically -extracts them and flattens the data into properties that can be accessed through Spring's -`Environment` abstraction, as shown in the following example: +Environment variables do not always make for the easiest API, so Spring Boot automatically extracts them and flattens the data into properties that can be accessed through Spring's `Environment` abstraction, as shown in the following example: [source,java,indent=0] ---- @@ -146,40 +123,35 @@ extracts them and flattens the data into properties that can be accessed through } ---- -All Cloud Foundry properties are prefixed with `vcap`. You can use `vcap` properties to -access application information (such as the public URL of the application) and service -information (such as database credentials). See the -{dc-spring-boot}/cloud/CloudFoundryVcapEnvironmentPostProcessor.html['`CloudFoundryVcapEnvironmentPostProcessor`'] -Javadoc for complete details. +All Cloud Foundry properties are prefixed with `vcap`. +You can use `vcap` properties to access application information (such as the public URL of the application) and service information (such as database credentials). +See the {dc-spring-boot}/cloud/CloudFoundryVcapEnvironmentPostProcessor.html['`CloudFoundryVcapEnvironmentPostProcessor`'] Javadoc for complete details. -TIP: The https://cloud.spring.io/spring-cloud-connectors/[Spring Cloud Connectors] project -is a better fit for tasks such as configuring a DataSource. Spring Boot includes -auto-configuration support and a `spring-boot-starter-cloud-connectors` starter. +TIP: The https://cloud.spring.io/spring-cloud-connectors/[Spring Cloud Connectors] project is a better fit for tasks such as configuring a DataSource. +Spring Boot includes auto-configuration support and a `spring-boot-starter-cloud-connectors` starter. [[cloud-deployment-heroku]] === Heroku -Heroku is another popular PaaS platform. To customize Heroku builds, you provide a -`Procfile`, which provides the incantation required to deploy an application. Heroku -assigns a `port` for the Java application to use and then ensures that routing to the -external URI works. +Heroku is another popular PaaS platform. +To customize Heroku builds, you provide a `Procfile`, which provides the incantation required to deploy an application. +Heroku assigns a `port` for the Java application to use and then ensures that routing to the external URI works. -You must configure your application to listen on the correct port. The following example -shows the `Procfile` for our starter REST application: +You must configure your application to listen on the correct port. +The following example shows the `Procfile` for our starter REST application: [indent=0] ---- web: java -Dserver.port=$PORT -jar target/demo-0.0.1-SNAPSHOT.jar ---- -Spring Boot makes `-D` arguments available as properties accessible from a Spring -`Environment` instance. The `server.port` configuration property is fed to the embedded -Tomcat, Jetty, or Undertow instance, which then uses the port when it starts up. The `$PORT` -environment variable is assigned to us by the Heroku PaaS. +Spring Boot makes `-D` arguments available as properties accessible from a Spring `Environment` instance. +The `server.port` configuration property is fed to the embedded Tomcat, Jetty, or Undertow instance, which then uses the port when it starts up. +The `$PORT` environment variable is assigned to us by the Heroku PaaS. -This should be everything you need. The most common deployment workflow for Heroku -deployments is to `git push` the code to production, as shown in the following example: +This should be everything you need. +The most common deployment workflow for Heroku deployments is to `git push` the code to production, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -224,17 +196,15 @@ deployments is to `git push` the code to production, as shown in the following e * [new branch] master -> master ---- -Your application should now be up and running on Heroku. For more details, refer to -https://devcenter.heroku.com/articles/deploying-spring-boot-apps-to-heroku[Deploying -Spring Boot Applications to Heroku]. +Your application should now be up and running on Heroku. +For more details, refer to https://devcenter.heroku.com/articles/deploying-spring-boot-apps-to-heroku[Deploying Spring Boot Applications to Heroku]. [[cloud-deployment-openshift]] === OpenShift -https://www.openshift.com/[OpenShift] is the Red Hat public (and enterprise) extension of -the Kubernetes container orchestration platform. Similarly to Kubernetes, OpenShift has -many options for installing Spring Boot based applications. +https://www.openshift.com/[OpenShift] is the Red Hat public (and enterprise) extension of the Kubernetes container orchestration platform. +Similarly to Kubernetes, OpenShift has many options for installing Spring Boot based applications. OpenShift has many resources describing how to deploy Spring Boot applications, including: @@ -244,11 +214,11 @@ OpenShift has many resources describing how to deploy Spring Boot applications, * https://blog.openshift.com/openshift-commons-briefing-96-cloud-native-applications-spring-rhoar/[OpenShift Commons Briefing] + [[cloud-deployment-aws]] === Amazon Web Services (AWS) -Amazon Web Services offers multiple ways to install Spring Boot-based applications, either -as traditional web applications (war) or as executable jar files with an embedded web -server. The options include: +Amazon Web Services offers multiple ways to install Spring Boot-based applications, either as traditional web applications (war) or as executable jar files with an embedded web server. +The options include: * AWS Elastic Beanstalk * AWS Code Deploy @@ -256,30 +226,28 @@ server. The options include: * AWS Cloud Formation * AWS Container Registry -Each has different features and pricing models. In this document, we describe only the -simplest option: AWS Elastic Beanstalk. +Each has different features and pricing models. +In this document, we describe only the simplest option: AWS Elastic Beanstalk. ==== AWS Elastic Beanstalk -As described in the official -https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/create_deploy_Java.html[Elastic -Beanstalk Java guide], there are two main options to deploy a Java application. You can -either use the "`Tomcat Platform`" or the "`Java SE platform`". +As described in the official https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/create_deploy_Java.html[Elastic Beanstalk Java guide], there are two main options to deploy a Java application. +You can either use the "`Tomcat Platform`" or the "`Java SE platform`". ===== Using the Tomcat Platform -This option applies to Spring Boot projects that produce a war file. No -special configuration is required. You need only follow the official guide. +This option applies to Spring Boot projects that produce a war file. +No special configuration is required. +You need only follow the official guide. ===== Using the Java SE Platform -This option applies to Spring Boot projects that produce a jar file and run an embedded -web container. Elastic Beanstalk environments run an nginx instance on port 80 to proxy -the actual application, running on port 5000. To configure it, add the following line to -your `application.properties` file: +This option applies to Spring Boot projects that produce a jar file and run an embedded web container. +Elastic Beanstalk environments run an nginx instance on port 80 to proxy the actual application, running on port 5000. +To configure it, add the following line to your `application.properties` file: [indent=0] ---- @@ -290,11 +258,9 @@ your `application.properties` file: [TIP] .Upload binaries instead of sources ==== -By default, Elastic Beanstalk uploads sources and compiles them in AWS. However, it is -best to upload the binaries instead. To do so, add lines similar to the following to your -`.elasticbeanstalk/config.yml` file: - - +By default, Elastic Beanstalk uploads sources and compiles them in AWS. +However, it is best to upload the binaries instead. +To do so, add lines similar to the following to your `.elasticbeanstalk/config.yml` file: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -306,12 +272,10 @@ best to upload the binaries instead. To do so, add lines similar to the followin [TIP] .Reduce costs by setting the environment type ==== -By default an Elastic Beanstalk environment is load balanced. The load balancer has a -significant cost. To avoid that cost, set the environment type to "`Single instance`", as -described in -https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/environments-create-wizard.html#environments-create-wizard-capacity[the -Amazon documentation]. You can also create single instance environments by using the CLI -and the following command: +By default an Elastic Beanstalk environment is load balanced. +The load balancer has a significant cost. +To avoid that cost, set the environment type to "`Single instance`", as described in https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/environments-create-wizard.html#environments-create-wizard-capacity[the Amazon documentation]. +You can also create single instance environments by using the CLI and the following command: [indent=0] ---- @@ -320,45 +284,33 @@ and the following command: ==== + ==== Summary -This is one of the easiest ways to get to AWS, but there are more things to cover, such as -how to integrate Elastic Beanstalk into any CI / CD tool, use the Elastic Beanstalk Maven -plugin instead of the CLI, and others. There is a -https://exampledriven.wordpress.com/2017/01/09/spring-boot-aws-elastic-beanstalk-example/[blog post] covering these topics more in detail. +This is one of the easiest ways to get to AWS, but there are more things to cover, such as how to integrate Elastic Beanstalk into any CI / CD tool, use the Elastic Beanstalk Maven plugin instead of the CLI, and others. +There is a https://exampledriven.wordpress.com/2017/01/09/spring-boot-aws-elastic-beanstalk-example/[blog post] covering these topics more in detail. [[cloud-deployment-boxfuse]] === Boxfuse and Amazon Web Services -https://boxfuse.com/[Boxfuse] works by turning your Spring Boot executable jar or war -into a minimal VM image that can be deployed unchanged either on VirtualBox or on AWS. -Boxfuse comes with deep integration for Spring Boot and uses the information from your -Spring Boot configuration file to automatically configure ports and health check URLs. -Boxfuse leverages this information both for the images it produces as well as for all the -resources it provisions (instances, security groups, elastic load balancers, and so on). +https://boxfuse.com/[Boxfuse] works by turning your Spring Boot executable jar or war into a minimal VM image that can be deployed unchanged either on VirtualBox or on AWS. +Boxfuse comes with deep integration for Spring Boot and uses the information from your Spring Boot configuration file to automatically configure ports and health check URLs. +Boxfuse leverages this information both for the images it produces as well as for all the resources it provisions (instances, security groups, elastic load balancers, and so on). -Once you have created a https://console.boxfuse.com[Boxfuse account], connected it to -your AWS account, installed the latest version of the Boxfuse Client, and ensured that -the application has been built by Maven or Gradle (by using, for example, `mvn clean -package`), you can deploy your Spring Boot application to AWS with a command similar to -the following: +Once you have created a https://console.boxfuse.com[Boxfuse account], connected it to your AWS account, installed the latest version of the Boxfuse Client, and ensured that the application has been built by Maven or Gradle (by using, for example, `mvn clean package`), you can deploy your Spring Boot application to AWS with a command similar to the following: [indent=0] ---- $ boxfuse run myapp-1.0.jar -env=prod ---- -See the https://boxfuse.com/docs/commandline/run.html[`boxfuse run` documentation] for -more options. If there is a https://boxfuse.com/docs/commandline/#configuration[`boxfuse.conf`] file present in the current directory, it is considered. +See the https://boxfuse.com/docs/commandline/run.html[`boxfuse run` documentation] for more options. +If there is a https://boxfuse.com/docs/commandline/#configuration[`boxfuse.conf`] file present in the current directory, it is considered. -TIP: By default, Boxfuse activates a Spring profile named `boxfuse` on startup. If your -executable jar or war contains an -https://boxfuse.com/docs/payloads/springboot.html#configuration[`application-boxfuse.properties`] file, Boxfuse bases its configuration on the -properties it contains. +TIP: By default, Boxfuse activates a Spring profile named `boxfuse` on startup. +If your executable jar or war contains an https://boxfuse.com/docs/payloads/springboot.html#configuration[`application-boxfuse.properties`] file, Boxfuse bases its configuration on the properties it contains. -At this point, `boxfuse` creates an image for your application, uploads it, and configures -and starts the necessary resources on AWS, resulting in output similar to the following -example: +At this point, `boxfuse` creates an image for your application, uploads it, and configures and starts the necessary resources on AWS, resulting in output similar to the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -383,32 +335,23 @@ example: Your application should now be up and running on AWS. -See the blog post on https://boxfuse.com/blog/spring-boot-ec2.html[deploying Spring Boot -apps on EC2] as well as the -https://boxfuse.com/docs/payloads/springboot.html[documentation for the Boxfuse Spring -Boot integration] to get started with a Maven build to run the app. +See the blog post on https://boxfuse.com/blog/spring-boot-ec2.html[deploying Spring Boot apps on EC2] as well as the https://boxfuse.com/docs/payloads/springboot.html[documentation for the Boxfuse Spring Boot integration] to get started with a Maven build to run the app. [[cloud-deployment-gae]] === Google Cloud Google Cloud has several options that can be used to launch Spring Boot applications. -The easiest to get started with is probably App Engine, but you could also find ways to -run Spring Boot in a container with Container Engine or on a virtual machine with -Compute Engine. +The easiest to get started with is probably App Engine, but you could also find ways to run Spring Boot in a container with Container Engine or on a virtual machine with Compute Engine. -To run in App Engine, you can create a project in the UI first, which sets up a unique -identifier for you and also sets up HTTP routes. Add a Java app to the project and leave -it empty and then use the https://cloud.google.com/sdk/downloads[Google Cloud SDK] to -push your Spring Boot app into that slot from the command line or CI build. +To run in App Engine, you can create a project in the UI first, which sets up a unique identifier for you and also sets up HTTP routes. +Add a Java app to the project and leave it empty and then use the https://cloud.google.com/sdk/downloads[Google Cloud SDK] to push your Spring Boot app into that slot from the command line or CI build. -App Engine Standard requires you to use WAR packaging. Follow -https://github.com/GoogleCloudPlatform/getting-started-java/blob/master/appengine-standard-java8/springboot-appengine-standard/README.md[these steps] -to deploy App Engine Standard application to Google Cloud. +App Engine Standard requires you to use WAR packaging. +Follow https://github.com/GoogleCloudPlatform/getting-started-java/blob/master/appengine-standard-java8/springboot-appengine-standard/README.md[these steps] to deploy App Engine Standard application to Google Cloud. -Alternatively, App Engine Flex requires you to create an `app.yaml` file to describe -the resources your app requires. Normally, you put this file in `src/main/appengine`, -and it should resemble the following file: +Alternatively, App Engine Flex requires you to create an `app.yaml` file to describe the resources your app requires. +Normally, you put this file in `src/main/appengine`, and it should resemble the following file: [source,yaml,indent=0] ---- @@ -434,8 +377,7 @@ and it should resemble the following file: ENCRYPT_KEY: your_encryption_key_here ---- -You can deploy the app (for example, with a Maven plugin) by adding the project ID to the -build configuration, as shown in the following example: +You can deploy the app (for example, with a Maven plugin) by adding the project ID to the build configuration, as shown in the following example: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -449,25 +391,19 @@ build configuration, as shown in the following example: ---- -Then deploy with `mvn appengine:deploy` (if you need to authenticate first, the build -fails). +Then deploy with `mvn appengine:deploy` (if you need to authenticate first, the build fails). [[deployment-install]] == Installing Spring Boot Applications -In addition to running Spring Boot applications by using `java -jar`, it is also -possible to make fully executable applications for Unix systems. A fully executable jar -can be executed like any other executable binary or it can be -<>. This makes it very easy to -install and manage Spring Boot applications in common production environments. +In addition to running Spring Boot applications by using `java -jar`, it is also possible to make fully executable applications for Unix systems. +A fully executable jar can be executed like any other executable binary or it can be <>. +This makes it very easy to install and manage Spring Boot applications in common production environments. CAUTION: Fully executable jars work by embedding an extra script at the front of the file. -Currently, some tools do not accept this format, so you may not always be able to use this -technique. For example, `jar -xf` may silently fail to extract a jar or war that has been -made fully executable. It is recommended that you make your jar or war fully executable -only if you intend to execute it directly, rather than running it with `java -jar` -or deploying it to a servlet container. +Currently, some tools do not accept this format, so you may not always be able to use this technique. For example, `jar -xf` may silently fail to extract a jar or war that has been made fully executable. +It is recommended that you make your jar or war fully executable only if you intend to execute it directly, rather than running it with `java -jar`or deploying it to a servlet container. To create a '`fully executable`' jar with Maven, use the following plugin configuration: @@ -491,30 +427,28 @@ The following example shows the equivalent Gradle configuration: } ---- -You can then run your application by typing `./my-application.jar` (where `my-application` -is the name of your artifact). The directory containing the jar is used as your -application's working directory. +You can then run your application by typing `./my-application.jar` (where `my-application` is the name of your artifact). +The directory containing the jar is used as your application's working directory. + + [[deployment-install-supported-operating-systems]] === Supported Operating Systems The default script supports most Linux distributions and is tested on CentOS and Ubuntu. -Other platforms, such as OS X and FreeBSD, require the use of a custom -`embeddedLaunchScript`. +Other platforms, such as OS X and FreeBSD, require the use of a custom `embeddedLaunchScript`. [[deployment-service]] === Unix/Linux Services -Spring Boot application can be easily started as Unix/Linux services by using either -`init.d` or `systemd`. +Spring Boot application can be easily started as Unix/Linux services by using either `init.d` or `systemd`. + [[deployment-initd-service]] ==== Installation as an `init.d` Service (System V) -If you configured Spring Boot's Maven or Gradle plugin to generate a <>, and you do not use a custom `embeddedLaunchScript`, your -application can be used as an `init.d` service. To do so, symlink the jar to `init.d` to -support the standard `start`, `stop`, `restart`, and `status` commands. +If you configured Spring Boot's Maven or Gradle plugin to generate a <>, and you do not use a custom `embeddedLaunchScript`, your application can be used as an `init.d` service. +To do so, symlink the jar to `init.d` to support the standard `start`, `stop`, `restart`, and `status` commands. The script supports the following features: @@ -522,27 +456,25 @@ The script supports the following features: * Tracks the application's PID by using `/var/run//.pid` * Writes console logs to `/var/log/.log` -Assuming that you have a Spring Boot application installed in `/var/myapp`, to install a -Spring Boot application as an `init.d` service, create a symlink, as follows: +Assuming that you have a Spring Boot application installed in `/var/myapp`, to install a Spring Boot application as an `init.d` service, create a symlink, as follows: [indent=0,subs="verbatim,quotes,attributes"] ---- $ sudo ln -s /var/myapp/myapp.jar /etc/init.d/myapp ---- -Once installed, you can start and stop the service in the usual way. For example, on a -Debian-based system, you could start it with the following command: +Once installed, you can start and stop the service in the usual way. +For example, on a Debian-based system, you could start it with the following command: [indent=0,subs="verbatim,quotes,attributes"] ---- $ service myapp start ---- -TIP: If your application fails to start, check the log file written to -`/var/log/.log` for errors. +TIP: If your application fails to start, check the log file written to `/var/log/.log` for errors. -You can also flag the application to start automatically by using your standard operating -system tools. For example, on Debian, you could use the following command: +You can also flag the application to start automatically by using your standard operating system tools. +For example, on Debian, you could use the following command: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -553,16 +485,12 @@ system tools. For example, on Debian, you could use the following command: [[deployment-initd-service-securing]] ===== Securing an `init.d` Service +NOTE: The following is a set of guidelines on how to secure a Spring Boot application that runs as an init.d service. +It is not intended to be an exhaustive list of everything that should be done to harden an application and the environment in which it runs. -NOTE: The following is a set of guidelines on how to secure a Spring Boot application that -runs as an init.d service. It is not intended to be an exhaustive list of everything that -should be done to harden an application and the environment in which it runs. - -When executed as root, as is the case when root is being used to start an init.d service, -the default executable script runs the application as the user who owns the jar file. You -should never run a Spring Boot application as `root`, so your application's jar file -should never be owned by root. Instead, create a specific user to run your application and -use `chown` to make it the owner of the jar file, as shown in the following example: +When executed as root, as is the case when root is being used to start an init.d service, the default executable script runs the application as the user who owns the jar file. +You should never run a Spring Boot application as `root`, so your application's jar file should never be owned by root. +Instead, create a specific user to run your application and use `chown` to make it the owner of the jar file, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -571,23 +499,20 @@ use `chown` to make it the owner of the jar file, as shown in the following exam In this case, the default executable script runs the application as the `bootapp` user. -TIP: To reduce the chances of the application's user account being compromised, you should -consider preventing it from using a login shell. For example, you can set the account's -shell to `/usr/sbin/nologin`. +TIP: To reduce the chances of the application's user account being compromised, you should consider preventing it from using a login shell. +For example, you can set the account's shell to `/usr/sbin/nologin`. You should also take steps to prevent the modification of your application's jar file. -Firstly, configure its permissions so that it cannot be written and can only be read or -executed by its owner, as shown in the following example: +Firstly, configure its permissions so that it cannot be written and can only be read or executed by its owner, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- $ chmod 500 your-app.jar ---- -Second, you should also take steps to limit the damage if your application or the account -that's running it is compromised. If an attacker does gain access, they could make the jar -file writable and change its contents. One way to protect against this is to make it -immutable by using `chattr`, as shown in the following example: +Second, you should also take steps to limit the damage if your application or the account that's running it is compromised. +If an attacker does gain access, they could make the jar file writable and change its contents. +One way to protect against this is to make it immutable by using `chattr`, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -596,11 +521,8 @@ immutable by using `chattr`, as shown in the following example: This will prevent any user, including root, from modifying the jar. -If root is used to control the application's service and you -<> to customize its -startup, the `.conf` file is read and evaluated by the root user. It should be secured -accordingly. Use `chmod` so that the file can only be read by the owner and use `chown` to -make root the owner, as shown in the following example: +If root is used to control the application's service and you <> to customize its startup, the `.conf` file is read and evaluated by the root user. +It should be secured accordingly. Use `chmod` so that the file can only be read by the owner and use `chown` to make root the owner, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -612,14 +534,11 @@ make root the owner, as shown in the following example: [[deployment-systemd-service]] ==== Installation as a `systemd` Service -`systemd` is the successor of the System V init system and is now being used by many -modern Linux distributions. Although you can continue to use `init.d` scripts with -`systemd`, it is also possible to launch Spring Boot applications by using `systemd` -'`service`' scripts. +`systemd` is the successor of the System V init system and is now being used by many modern Linux distributions. +Although you can continue to use `init.d` scripts with `systemd`, it is also possible to launch Spring Boot applications by using `systemd` '`service`' scripts. -Assuming that you have a Spring Boot application installed in `/var/myapp`, to install a -Spring Boot application as a `systemd` service, create a script named `myapp.service` and -place it in `/etc/systemd/system` directory. The following script offers an example: +Assuming that you have a Spring Boot application installed in `/var/myapp`, to install a Spring Boot application as a `systemd` service, create a script named `myapp.service` and place it in `/etc/systemd/system` directory. +The following script offers an example: [indent=0] ---- @@ -636,17 +555,12 @@ place it in `/etc/systemd/system` directory. The following script offers an exam WantedBy=multi-user.target ---- -IMPORTANT: Remember to change the `Description`, `User`, and `ExecStart` fields for your -application. +IMPORTANT: Remember to change the `Description`, `User`, and `ExecStart` fields for your application. -NOTE: The `ExecStart` field does not declare the script action command, which means that -the `run` command is used by default. +NOTE: The `ExecStart` field does not declare the script action command, which means that the `run` command is used by default. -Note that, unlike when running as an `init.d` service, the user that runs the application, -the PID file, and the console log file are managed by `systemd` itself and therefore must -be configured by using appropriate fields in the '`service`' script. Consult the -https://www.freedesktop.org/software/systemd/man/systemd.service.html[service unit -configuration man page] for more details. +Note that, unlike when running as an `init.d` service, the user that runs the application, the PID file, and the console log file are managed by `systemd` itself and therefore must be configured by using appropriate fields in the '`service`' script. +Consult the https://www.freedesktop.org/software/systemd/man/systemd.service.html[service unit configuration man page] for more details. To flag the application to start automatically on system boot, use the following command: @@ -661,197 +575,180 @@ Refer to `man systemctl` for more details. [[deployment-script-customization]] ==== Customizing the Startup Script -The default embedded startup script written by the Maven or Gradle plugin can be -customized in a number of ways. For most people, using the default script along with a few -customizations is usually enough. If you find you cannot customize something that you need -to, use the `embeddedLaunchScript` option to write your own file entirely. +The default embedded startup script written by the Maven or Gradle plugin can be customized in a number of ways. +For most people, using the default script along with a few customizations is usually enough. +If you find you cannot customize something that you need to, use the `embeddedLaunchScript` option to write your own file entirely. [[deployment-script-customization-when-it-written]] ===== Customizing the Start Script when It Is Written -It often makes sense to customize elements of the start script as it is written into the -jar file. For example, init.d scripts can provide a "`description`". Since you know the -description up front (and it need not change), you may as well provide it when the jar is -generated. +It often makes sense to customize elements of the start script as it is written into the jar file. +For example, init.d scripts can provide a "`description`". +Since you know the description up front (and it need not change), you may as well provide it when the jar is generated. -To customize written elements, use the `embeddedLaunchScriptProperties` option of the -Spring Boot Maven plugin or the -{spring-boot-gradle-plugin-reference}/#packaging-executable-configuring-launch-script[`properties` -property of the Spring Boot Gradle plugin's `launchScript`]. +To customize written elements, use the `embeddedLaunchScriptProperties` option of the Spring Boot Maven plugin or the {spring-boot-gradle-plugin-reference}/#packaging-executable-configuring-launch-script[`properties` property of the Spring Boot Gradle plugin's `launchScript`]. The following property substitutions are supported with the default script: [cols="1,3,3,3"] |=== -|Name |Description |Gradle default |Maven default +| Name | Description | Gradle default | Maven default -|`mode` -|The script mode. -|`auto` -|`auto` +| `mode` +| The script mode. +| `auto` +| `auto` -|`initInfoProvides` -|The `Provides` section of "`INIT INFO`" -|`${task.baseName}` -|`${project.artifactId}` +| `initInfoProvides` +| The `Provides` section of "`INIT INFO`" +| `${task.baseName}` +| `${project.artifactId}` -|`initInfoRequiredStart` -|`Required-Start` section of "`INIT INFO`". -|`$remote_fs $syslog $network` -|`$remote_fs $syslog $network` +| `initInfoRequiredStart` +| `Required-Start` section of "`INIT INFO`". +| `$remote_fs $syslog $network` +| `$remote_fs $syslog $network` -|`initInfoRequiredStop` -|`Required-Stop` section of "`INIT INFO`". -|`$remote_fs $syslog $network` -|`$remote_fs $syslog $network` +| `initInfoRequiredStop` +| `Required-Stop` section of "`INIT INFO`". +| `$remote_fs $syslog $network` +| `$remote_fs $syslog $network` -|`initInfoDefaultStart` -|`Default-Start` section of "`INIT INFO`". -|`2 3 4 5` -|`2 3 4 5` +| `initInfoDefaultStart` +| `Default-Start` section of "`INIT INFO`". +| `2 3 4 5` +| `2 3 4 5` -|`initInfoDefaultStop` -|`Default-Stop` section of "`INIT INFO`". -|`0 1 6` -|`0 1 6` +| `initInfoDefaultStop` +| `Default-Stop` section of "`INIT INFO`". +| `0 1 6` +| `0 1 6` -|`initInfoShortDescription` -|`Short-Description` section of "`INIT INFO`". -|Single-line version of `${project.description}` (falling back to `${task.baseName}`) -|`${project.name}` +| `initInfoShortDescription` +| `Short-Description` section of "`INIT INFO`". +| Single-line version of `${project.description}` (falling back to `${task.baseName}`) +| `${project.name}` -|`initInfoDescription` -|`Description` section of "`INIT INFO`". -|`${project.description}` (falling back to `${task.baseName}`) -|`${project.description}` (falling back to `${project.name}`) +| `initInfoDescription` +| `Description` section of "`INIT INFO`". +| `${project.description}` (falling back to `${task.baseName}`) +| `${project.description}` (falling back to `${project.name}`) -|`initInfoChkconfig` -|`chkconfig` section of "`INIT INFO`" -|`2345 99 01` -|`2345 99 01` +| `initInfoChkconfig` +| `chkconfig` section of "`INIT INFO`" +| `2345 99 01` +| `2345 99 01` -|`confFolder` -|The default value for `CONF_FOLDER` -|Folder containing the jar -|Folder containing the jar +| `confFolder` +| The default value for `CONF_FOLDER` +| Folder containing the jar +| Folder containing the jar -|`inlinedConfScript` -|Reference to a file script that should be inlined in the default launch script. - This can be used to set environmental variables such as `JAVA_OPTS` before any external - config files are loaded +| `inlinedConfScript` +| Reference to a file script that should be inlined in the default launch script. + This can be used to set environmental variables such as `JAVA_OPTS` before any external config files are loaded | | -|`logFolder` -|Default value for `LOG_FOLDER`. Only valid for an `init.d` service +| `logFolder` +| Default value for `LOG_FOLDER`. Only valid for an `init.d` service | | -|`logFilename` -|Default value for `LOG_FILENAME`. Only valid for an `init.d` service +| `logFilename` +| Default value for `LOG_FILENAME`. Only valid for an `init.d` service | | -|`pidFolder` -|Default value for `PID_FOLDER`. Only valid for an `init.d` service +| `pidFolder` +| Default value for `PID_FOLDER`. Only valid for an `init.d` service | | -|`pidFilename` -|Default value for the name of the PID file in `PID_FOLDER`. Only valid for an - `init.d` service +| `pidFilename` +| Default value for the name of the PID file in `PID_FOLDER`. + Only valid for an `init.d` service | | -|`useStartStopDaemon` -|Whether the `start-stop-daemon` command, when it's available, should be used to control - the process -|`true` -|`true` +| `useStartStopDaemon` +| Whether the `start-stop-daemon` command, when it's available, should be used to control the process +| `true` +| `true` -|`stopWaitTime` -|Default value for `STOP_WAIT_TIME` in seconds. Only valid for an `init.d` service -|60 -|60 +| `stopWaitTime` +| Default value for `STOP_WAIT_TIME` in seconds. Only valid for an `init.d` service +| 60 +| 60 |=== + [[deployment-script-customization-when-it-runs]] ===== Customizing a Script When It Runs -For items of the script that need to be customized _after_ the jar has been written, you -can use environment variables or a <>. +For items of the script that need to be customized _after_ the jar has been written, you can use environment variables or a <>. The following environment properties are supported with the default script: [cols="1,6"] |=== -|Variable |Description +| Variable | Description -|`MODE` -|The "`mode`" of operation. The default depends on the way the jar was built but is - usually `auto` (meaning it tries to guess if it is an init script by checking if it is a - symlink in a directory called `init.d`). You can explicitly set it to `service` so that - the `stop\|start\|status\|restart` commands work or to `run` if you want to run the - script in the foreground. +| `MODE` +| The "`mode`" of operation. + The default depends on the way the jar was built but is usually `auto` (meaning it tries to guess if it is an init script by checking if it is a symlink in a directory called `init.d`). + You can explicitly set it to `service` so that the `stop\|start\|status\|restart` commands work or to `run` if you want to run the script in the foreground. -|`USE_START_STOP_DAEMON` -|Whether the `start-stop-daemon` command, when it's available, should be used to control - the process. Defaults to `true`. +| `USE_START_STOP_DAEMON` +| Whether the `start-stop-daemon` command, when it's available, should be used to control the process. + Defaults to `true`. -|`PID_FOLDER` -|The root name of the pid folder (`/var/run` by default). +| `PID_FOLDER` +| The root name of the pid folder (`/var/run` by default). -|`LOG_FOLDER` -|The name of the folder in which to put log files (`/var/log` by default). +| `LOG_FOLDER` +| The name of the folder in which to put log files (`/var/log` by default). -|`CONF_FOLDER` -|The name of the folder from which to read .conf files (same folder as jar-file by - default). +| `CONF_FOLDER` +| The name of the folder from which to read .conf files (same folder as jar-file by default). -|`LOG_FILENAME` -|The name of the log file in the `LOG_FOLDER` (`.log` by default). +| `LOG_FILENAME` +| The name of the log file in the `LOG_FOLDER` (`.log` by default). -|`APP_NAME` -|The name of the app. If the jar is run from a symlink, the script guesses the app name. -If it is not a symlink or you want to explicitly set the app name, this can be useful. +| `APP_NAME` +| The name of the app. + If the jar is run from a symlink, the script guesses the app name. + If it is not a symlink or you want to explicitly set the app name, this can be useful. -|`RUN_ARGS` -|The arguments to pass to the program (the Spring Boot app). +| `RUN_ARGS` +| The arguments to pass to the program (the Spring Boot app). -|`JAVA_HOME` -|The location of the `java` executable is discovered by using the `PATH` by default, but - you can set it explicitly if there is an executable file at `$JAVA_HOME/bin/java`. +| `JAVA_HOME` +| The location of the `java` executable is discovered by using the `PATH` by default, but you can set it explicitly if there is an executable file at `$JAVA_HOME/bin/java`. -|`JAVA_OPTS` -|Options that are passed to the JVM when it is launched. +| `JAVA_OPTS` +| Options that are passed to the JVM when it is launched. -|`JARFILE` -|The explicit location of the jar file, in case the script is being used to launch a jar - that it is not actually embedded. +| `JARFILE` +| The explicit location of the jar file, in case the script is being used to launch a jar that it is not actually embedded. -|`DEBUG` -|If not empty, sets the `-x` flag on the shell process, making it easy to see the logic - in the script. +| `DEBUG` +| If not empty, sets the `-x` flag on the shell process, making it easy to see the logic in the script. -|`STOP_WAIT_TIME` -|The time in seconds to wait when stopping the application before forcing a shutdown (`60` - by default). +| `STOP_WAIT_TIME` +| The time in seconds to wait when stopping the application before forcing a shutdown (`60` by default). |=== -NOTE: The `PID_FOLDER`, `LOG_FOLDER`, and `LOG_FILENAME` variables are only valid for an -`init.d` service. For `systemd`, the equivalent customizations are made by using the -'`service`' script. See the -https://www.freedesktop.org/software/systemd/man/systemd.service.html[service unit -configuration man page] for more details. +NOTE: The `PID_FOLDER`, `LOG_FOLDER`, and `LOG_FILENAME` variables are only valid for an `init.d` service. For `systemd`, the equivalent customizations are made by using the '`service`' script. +See the https://www.freedesktop.org/software/systemd/man/systemd.service.html[service unit configuration man page] for more details. + + [[deployment-script-customization-conf-file]] -With the exception of `JARFILE` and `APP_NAME`, the settings listed in the preceding -section can be configured by using a `.conf` file. The file is expected to be next to the -jar file and have the same name but suffixed with `.conf` rather than `.jar`. For example, -a jar named `/var/myapp/myapp.jar` uses the configuration file named -`/var/myapp/myapp.conf`, as shown in the following example: +With the exception of `JARFILE` and `APP_NAME`, the settings listed in the preceding section can be configured by using a `.conf` file. +The file is expected to be next to the jar file and have the same name but suffixed with `.conf` rather than `.jar`. +For example, a jar named `/var/myapp/myapp.jar` uses the configuration file named `/var/myapp/myapp.conf`, as shown in the following example: .myapp.conf [indent=0,subs="verbatim,quotes,attributes"] @@ -860,33 +757,24 @@ a jar named `/var/myapp/myapp.jar` uses the configuration file named LOG_FOLDER=/custom/log/folder ---- -TIP: If you do not like having the config file next to the jar file, you can set a -`CONF_FOLDER` environment variable to customize the location of the config file. +TIP: If you do not like having the config file next to the jar file, you can set a `CONF_FOLDER` environment variable to customize the location of the config file. + +To learn about securing this file appropriately, see <>. -To learn about securing this file appropriately, see -<>. [[deployment-windows]] === Microsoft Windows Services -A Spring Boot application can be started as a Windows service by using -https://github.com/kohsuke/winsw[`winsw`]. +A Spring Boot application can be started as a Windows service by using https://github.com/kohsuke/winsw[`winsw`]. -A (https://github.com/snicoll-scratches/spring-boot-daemon[separately maintained sample]) -describes step-by-step how you can create a Windows service for your Spring Boot -application. +A (https://github.com/snicoll-scratches/spring-boot-daemon[separately maintained sample]) describes step-by-step how you can create a Windows service for your Spring Boot application. [[deployment-whats-next]] == What to Read Next -Check out the https://www.cloudfoundry.org/[Cloud Foundry], -https://www.heroku.com/[Heroku], https://www.openshift.com[OpenShift], and -https://boxfuse.com[Boxfuse] web sites for more information about the kinds of features -that a PaaS can offer. These are just four of the most popular Java PaaS providers. Since -Spring Boot is so amenable to cloud-based deployment, you can freely consider other -providers as well. +Check out the https://www.cloudfoundry.org/[Cloud Foundry], https://www.heroku.com/[Heroku], https://www.openshift.com[OpenShift], and https://boxfuse.com[Boxfuse] web sites for more information about the kinds of features that a PaaS can offer. +These are just four of the most popular Java PaaS providers. +Since Spring Boot is so amenable to cloud-based deployment, you can freely consider other providers as well. -The next section goes on to cover the _<>_, -or you can jump ahead to read about -_<>_. +The next section goes on to cover the _<>_, or you can jump ahead to read about _<>_. diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/documentation-overview.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/documentation-overview.adoc index cc725808802..92dd2ababcc 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/documentation-overview.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/documentation-overview.adoc @@ -3,26 +3,23 @@ [partintro] -- -This section provides a brief overview of Spring Boot reference documentation. It serves -as a map for the rest of the document. +This section provides a brief overview of Spring Boot reference documentation. +It serves as a map for the rest of the document. -- [[boot-documentation-about]] == About the Documentation -The Spring Boot reference guide is available as +The Spring Boot reference guide is available as: * {spring-boot-docs}/html[HTML] * {spring-boot-docs}/pdf/spring-boot-reference.pdf[PDF] * {spring-boot-docs}/epub/spring-boot-reference.epub[EPUB] -The latest copy -is available at {spring-boot-docs-current}. +The latest copy is available at {spring-boot-docs-current}. -Copies of this document may be made for your own use and for distribution to others, -provided that you do not charge any fee for such copies and further provided that each -copy contains this Copyright Notice, whether distributed in print or electronically. +Copies of this document may be made for your own use and for distribution to others, provided that you do not charge any fee for such copies and further provided that each copy contains this Copyright Notice, whether distributed in print or electronically. @@ -30,63 +27,39 @@ copy contains this Copyright Notice, whether distributed in print or electronica == Getting Help If you have trouble with Spring Boot, we would like to help. -* Try the <>. They provide solutions to the most -common questions. -* Learn the Spring basics. Spring Boot builds on many other Spring projects. Check the -https://spring.io[spring.io] web-site for a wealth of reference documentation. If you are -starting out with Spring, try one of the https://spring.io/guides[guides]. -* Ask a question. We monitor https://stackoverflow.com[stackoverflow.com] for questions -tagged with https://stackoverflow.com/tags/spring-boot[`spring-boot`]. +* Try the <>. + They provide solutions to the most common questions. +* Learn the Spring basics. + Spring Boot builds on many other Spring projects. + Check the https://spring.io[spring.io] web-site for a wealth of reference documentation. + If you are starting out with Spring, try one of the https://spring.io/guides[guides]. +* Ask a question. + We monitor https://stackoverflow.com[stackoverflow.com] for questions tagged with https://stackoverflow.com/tags/spring-boot[`spring-boot`]. * Report bugs with Spring Boot at https://github.com/spring-projects/spring-boot/issues. -NOTE: All of Spring Boot is open source, including the documentation. If you find -problems with the docs or if you want to improve them, please {github-code}[get -involved]. +NOTE: All of Spring Boot is open source, including the documentation. +If you find problems with the docs or if you want to improve them, please {github-code}[get involved]. [[boot-documentation-first-steps]] == First Steps -If you are getting started with Spring Boot or 'Spring' in general, start with -<>: +If you are getting started with Spring Boot or 'Spring' in general, start with <>: -* *From scratch:* -<> | -<> | -<> -* *Tutorial:* -<> | -<> -* *Running your example:* -<> | -<> +* *From scratch:* <> | <> | <> +* *Tutorial:* <> | <> +* *Running your example:* <> | <> == Working with Spring Boot -Ready to actually start using Spring Boot? <>: +Ready to actually start using Spring Boot? <>: -* *Build systems:* -<> | -<> | -<> | -<> -* *Best practices:* -<> | -<> | -<> | -<> -* *Running your code:* -<> | -<> | -<> | -<> -* *Packaging your app:* -<> -* *Spring Boot CLI:* -<> +* *Build systems:* <> | <> | <> | <> +* *Best practices:* <> | <> | <> | <> +* *Running your code:* <> | <> | <> | <> +* *Packaging your app:* <> +* *Spring Boot CLI:* <> @@ -94,62 +67,28 @@ Dependency Injection>> Need more details about Spring Boot's core features? <>: -* *Core Features:* -<> | -<> | -<> | -<> -* *Web Applications:* -<> | -<> -* *Working with data:* -<> | -<> -* *Messaging:* -<> | -<> -* *Testing:* -<> | -<> | -<> -* *Extending:* -<> | -<> +* *Core Features:* <> | <> | <> | <> +* *Web Applications:* <> | <> +* *Working with data:* <> | <> +* *Messaging:* <> | <> +* *Testing:* <> | <> | <> +* *Extending:* <> | <> == Moving to Production -When you are ready to push your Spring Boot application to production, we have -<> that you might like: +When you are ready to push your Spring Boot application to production, we have <> that you might like: -* *Management endpoints:* -<> | -<> -* *Connection options:* -<> | -<> -* *Monitoring:* -<> | -<> | -<> | -<> +* *Management endpoints:* <> | <> +* *Connection options:* <> | <> +* *Monitoring:* <> | <> | <> | <> == Advanced Topics Finally, we have a few topics for more advanced users: -* *Spring Boot Applications Deployment:* -<> | -<> -* *Build tool plugins:* -<> | -<> -* *Appendix:* -<> | -<> | -<> +* *Spring Boot Applications Deployment:* <> | <> +* *Build tool plugins:* <> | <> +* *Appendix:* <> | <> | <> diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/getting-started.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/getting-started.adoc index bfb631cec28..1c36e21343d 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/getting-started.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/getting-started.adoc @@ -3,55 +3,47 @@ [partintro] -- -If you are getting started with Spring Boot, or "`Spring`" in general, start by reading -this section. It answers the basic "`what?`", "`how?`" and "`why?`" questions. It -includes an introduction to Spring Boot, along with installation instructions. We then -walk you through building your first Spring Boot application, discussing some core -principles as we go. +If you are getting started with Spring Boot, or "`Spring`" in general, start by reading this section. +It answers the basic "`what?`", "`how?`" and "`why?`" questions. +It includes an introduction to Spring Boot, along with installation instructions. +We then walk you through building your first Spring Boot application, discussing some core principles as we go. -- [[getting-started-introducing-spring-boot]] == Introducing Spring Boot -Spring Boot makes it easy to create stand-alone, production-grade Spring-based -Applications that you can run. We take an opinionated view of the Spring platform and -third-party libraries, so that you can get started with minimum fuss. Most Spring Boot -applications need very little Spring configuration. +Spring Boot makes it easy to create stand-alone, production-grade Spring-based Applications that you can run. +We take an opinionated view of the Spring platform and third-party libraries, so that you can get started with minimum fuss. +Most Spring Boot applications need very little Spring configuration. -You can use Spring Boot to create Java applications that can be started by using -`java -jar` or more traditional war deployments. We also provide a command line tool that -runs "`spring scripts`". +You can use Spring Boot to create Java applications that can be started by using `java -jar` or more traditional war deployments. +We also provide a command line tool that runs "`spring scripts`". Our primary goals are: -* Provide a radically faster and widely accessible getting-started experience for all -Spring development. -* Be opinionated out of the box but get out of the way quickly as requirements start to -diverge from the defaults. -* Provide a range of non-functional features that are common to large classes of projects -(such as embedded servers, security, metrics, health checks, and externalized -configuration). +* Provide a radically faster and widely accessible getting-started experience for all Spring development. +* Be opinionated out of the box but get out of the way quickly as requirements start to diverge from the defaults. +* Provide a range of non-functional features that are common to large classes of projects (such as embedded servers, security, metrics, health checks, and externalized configuration). * Absolutely no code generation and no requirement for XML configuration. [[getting-started-system-requirements]] == System Requirements -Spring Boot {spring-boot-version} requires https://www.java.com[Java 8] and is compatible -up to Java 12 (included). {spring-reference}[Spring Framework {spring-framework-version}] -or above is also required. +Spring Boot {spring-boot-version} requires https://www.java.com[Java 8] and is compatible up to Java 12 (included). +{spring-reference}[Spring Framework {spring-framework-version}] or above is also required. Explicit build support is provided for the following build tools: |=== -|Build Tool |Version +| Build Tool | Version -|Maven -|3.3+ +| Maven +| 3.3+ -|Gradle -|4.4+ +| Gradle +| 4.4+ |=== @@ -61,16 +53,16 @@ Explicit build support is provided for the following build tools: Spring Boot supports the following embedded servlet containers: |=== -|Name |Servlet Version +| Name | Servlet Version -|Tomcat 9.0 -|4.0 +| Tomcat 9.0 +| 4.0 -|Jetty 9.4 -|3.1 +| Jetty 9.4 +| 3.1 -|Undertow 2.0 -|4.0 +| Undertow 2.0 +| 4.0 |=== You can also deploy Spring Boot applications to any Servlet 3.1+ compatible container. @@ -79,50 +71,44 @@ You can also deploy Spring Boot applications to any Servlet 3.1+ compatible cont [[getting-started-installing-spring-boot]] == Installing Spring Boot -Spring Boot can be used with "`classic`" Java development tools or installed as a command -line tool. Either way, you need https://www.java.com[Java SDK v1.8] or higher. Before you -begin, you should check your current Java installation by using the following command: +Spring Boot can be used with "`classic`" Java development tools or installed as a command line tool. +Either way, you need https://www.java.com[Java SDK v1.8] or higher. +Before you begin, you should check your current Java installation by using the following command: [indent=0] ---- $ java -version ---- -If you are new to Java development or if you want to experiment with Spring Boot, you -might want to try the <> (Command -Line Interface) first. Otherwise, read on for "`classic`" installation instructions. +If you are new to Java development or if you want to experiment with Spring Boot, you might want to try the <> (Command Line Interface) first. +Otherwise, read on for "`classic`" installation instructions. [[getting-started-installation-instructions-for-java]] === Installation Instructions for the Java Developer -You can use Spring Boot in the same way as any standard Java library. To do so, include -the appropriate `+spring-boot-*.jar+` files on your classpath. Spring Boot does not -require any special tools integration, so you can use any IDE or text editor. Also, there -is nothing special about a Spring Boot application, so you can run and debug a Spring -Boot application as you would any other Java program. +You can use Spring Boot in the same way as any standard Java library. +To do so, include the appropriate `+spring-boot-*.jar+` files on your classpath. +Spring Boot does not require any special tools integration, so you can use any IDE or text editor. +Also, there is nothing special about a Spring Boot application, so you can run and debug a Spring Boot application as you would any other Java program. -Although you _could_ copy Spring Boot jars, we generally recommend that you use a build -tool that supports dependency management (such as Maven or Gradle). +Although you _could_ copy Spring Boot jars, we generally recommend that you use a build tool that supports dependency management (such as Maven or Gradle). [[getting-started-maven-installation]] ==== Maven Installation -Spring Boot is compatible with Apache Maven 3.3 or above. If you do not already have -Maven installed, you can follow the instructions at https://maven.apache.org. +Spring Boot is compatible with Apache Maven 3.3 or above. +If you do not already have Maven installed, you can follow the instructions at https://maven.apache.org. -TIP: On many operating systems, Maven can be installed with a package manager. If you use -OSX Homebrew, try `brew install maven`. Ubuntu users can run -`sudo apt-get install maven`. Windows users with https://chocolatey.org/[Chocolatey] can -run `choco install maven` from an elevated (administrator) prompt. +TIP: On many operating systems, Maven can be installed with a package manager. +If you use OSX Homebrew, try `brew install maven`. +Ubuntu users can run `sudo apt-get install maven`. +Windows users with https://chocolatey.org/[Chocolatey] can run `choco install maven` from an elevated (administrator) prompt. -Spring Boot dependencies use the `org.springframework.boot` `groupId`. Typically, your -Maven POM file inherits from the `spring-boot-starter-parent` project and declares -dependencies to one or more <>. -Spring Boot also provides an optional -<> to create -executable jars. +Spring Boot dependencies use the `org.springframework.boot` `groupId`. +Typically, your Maven POM file inherits from the `spring-boot-starter-parent` project and declares dependencies to one or more <>. +Spring Boot also provides an optional <> to create executable jars. The following listing shows a typical `pom.xml` file: @@ -190,47 +176,38 @@ endif::[] ---- -TIP: The `spring-boot-starter-parent` is a great way to use Spring Boot, but it might not -be suitable all of the time. Sometimes you may need to inherit from a different parent -POM, or you might not like our default settings. In those cases, see -<> for an alternative solution that uses an `import` -scope. +TIP: The `spring-boot-starter-parent` is a great way to use Spring Boot, but it might not be suitable all of the time. +Sometimes you may need to inherit from a different parent POM, or you might not like our default settings. +In those cases, see <> for an alternative solution that uses an `import` scope. [[getting-started-gradle-installation]] ==== Gradle Installation -Spring Boot is compatible with Gradle 4.4 and later. If you do not already have Gradle -installed, you can follow the instructions at https://gradle.org. +Spring Boot is compatible with Gradle 4.4 and later. +If you do not already have Gradle installed, you can follow the instructions at https://gradle.org. Spring Boot dependencies can be declared by using the `org.springframework.boot` `group`. -Typically, your project declares dependencies to one or more -<>. Spring Boot -provides a useful <> that can be used to simplify dependency declarations and to create executable -jars. +Typically, your project declares dependencies to one or more <>. +Spring Boot provides a useful <> that can be used to simplify dependency declarations and to create executable jars. .Gradle Wrapper **** -The Gradle Wrapper provides a nice way of "`obtaining`" Gradle when you need to build a -project. It is a small script and library that you commit alongside your code to -bootstrap the build process. See {gradle-user-guide}/gradle_wrapper.html for details. +The Gradle Wrapper provides a nice way of "`obtaining`" Gradle when you need to build a project. +It is a small script and library that you commit alongside your code to bootstrap the build process. +See {gradle-user-guide}/gradle_wrapper.html for details. **** -More details on getting started with Spring Boot and Gradle can be found in the -{spring-boot-gradle-plugin-reference}/#getting-started[Getting Started section] of the -Gradle plugin's reference guide. +More details on getting started with Spring Boot and Gradle can be found in the {spring-boot-gradle-plugin-reference}/#getting-started[Getting Started section] of the Gradle plugin's reference guide. [[getting-started-installing-the-cli]] === Installing the Spring Boot CLI -The Spring Boot CLI (Command Line Interface) is a command line tool that you can use to -quickly prototype with Spring. It lets you run http://groovy-lang.org/[Groovy] scripts, -which means that you have a familiar Java-like syntax without so much boilerplate code. +The Spring Boot CLI (Command Line Interface) is a command line tool that you can use to quickly prototype with Spring. +It lets you run http://groovy-lang.org/[Groovy] scripts, which means that you have a familiar Java-like syntax without so much boilerplate code. -You do not need to use the CLI to work with Spring Boot, but it is definitely the -quickest way to get a Spring application off the ground. +You do not need to use the CLI to work with Spring Boot, but it is definitely the quickest way to get a Spring application off the ground. @@ -242,24 +219,18 @@ You can download the Spring CLI distribution from the Spring software repository * https://repo.spring.io/{spring-boot-repo}/org/springframework/boot/spring-boot-cli/{spring-boot-version}/spring-boot-cli-{spring-boot-version}-bin.tar.gz[spring-boot-cli-{spring-boot-version}-bin.tar.gz] Cutting edge -https://repo.spring.io/snapshot/org/springframework/boot/spring-boot-cli/[snapshot -distributions] are also available. +https://repo.spring.io/snapshot/org/springframework/boot/spring-boot-cli/[snapshot distributions] are also available. -Once downloaded, follow the -{github-raw}/spring-boot-project/spring-boot-cli/src/main/content/INSTALL.txt[INSTALL.txt] -instructions from the unpacked archive. In summary, there is a `spring` script -(`spring.bat` for Windows) in a `bin/` directory in the `.zip` file. Alternatively, you -can use `java -jar` with the `.jar` file (the script helps you to be sure that the -classpath is set correctly). +Once downloaded, follow the {github-raw}/spring-boot-project/spring-boot-cli/src/main/content/INSTALL.txt[INSTALL.txt] instructions from the unpacked archive. +In summary, there is a `spring` script (`spring.bat` for Windows) in a `bin/` directory in the `.zip` file. +Alternatively, you can use `java -jar` with the `.jar` file (the script helps you to be sure that the classpath is set correctly). [[getting-started-sdkman-cli-installation]] ==== Installation with SDKMAN! -SDKMAN! (The Software Development Kit Manager) can be used for managing multiple versions -of various binary SDKs, including Groovy and the Spring Boot CLI. -Get SDKMAN! from https://sdkman.io and install Spring Boot by using the following -commands: +SDKMAN! (The Software Development Kit Manager) can be used for managing multiple versions of various binary SDKs, including Groovy and the Spring Boot CLI. +Get SDKMAN! from https://sdkman.io and install Spring Boot by using the following commands: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -268,8 +239,7 @@ commands: Spring Boot v{spring-boot-version} ---- -If you develop features for the CLI and want easy access to the version you built, -use the following commands: +If you develop features for the CLI and want easy access to the version you built, use the following commands: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -279,9 +249,8 @@ use the following commands: Spring CLI v{spring-boot-version} ---- -The preceding instructions install a local instance of `spring` called the `dev` -instance. It points at your target build location, so every time you rebuild Spring Boot, -`spring` is up-to-date. +The preceding instructions install a local instance of `spring` called the `dev` instance. +It points at your target build location, so every time you rebuild Spring Boot, `spring` is up-to-date. You can see it by running the following command: @@ -306,8 +275,7 @@ You can see it by running the following command: [[getting-started-homebrew-cli-installation]] ==== OSX Homebrew Installation -If you are on a Mac and use https://brew.sh/[Homebrew], you can install the Spring Boot -CLI by using the following commands: +If you are on a Mac and use https://brew.sh/[Homebrew], you can install the Spring Boot CLI by using the following commands: [indent=0] ---- @@ -317,15 +285,14 @@ CLI by using the following commands: Homebrew installs `spring` to `/usr/local/bin`. -NOTE: If you do not see the formula, your installation of brew might be out-of-date. In -that case, run `brew update` and try again. +NOTE: If you do not see the formula, your installation of brew might be out-of-date. +In that case, run `brew update` and try again. [[getting-started-macports-cli-installation]] ==== MacPorts Installation -If you are on a Mac and use https://www.macports.org/[MacPorts], you can install the -Spring Boot CLI by using the following command: +If you are on a Mac and use https://www.macports.org/[MacPorts], you can install the Spring Boot CLI by using the following command: [indent=0] ---- @@ -336,14 +303,10 @@ Spring Boot CLI by using the following command: [[getting-started-cli-command-line-completion]] ==== Command-line Completion -The Spring Boot CLI includes scripts that provide command completion for the -https://en.wikipedia.org/wiki/Bash_%28Unix_shell%29[BASH] and -https://en.wikipedia.org/wiki/Z_shell[zsh] shells. You can `source` the script (also named -`spring`) in any shell or put it in your personal or system-wide bash completion -initialization. On a Debian system, the system-wide scripts are in -`/shell-completion/bash` and all scripts in that directory are executed when a new shell -starts. For example, to run the script manually if you have installed by using SDKMAN!, -use the following commands: +The Spring Boot CLI includes scripts that provide command completion for the https://en.wikipedia.org/wiki/Bash_%28Unix_shell%29[BASH] and https://en.wikipedia.org/wiki/Z_shell[zsh] shells. +You can `source` the script (also named `spring`) in any shell or put it in your personal or system-wide bash completion initialization. +On a Debian system, the system-wide scripts are in `/shell-completion/bash` and all scripts in that directory are executed when a new shell starts. +For example, to run the script manually if you have installed by using SDKMAN!, use the following commands: [indent=0] ---- @@ -352,15 +315,13 @@ use the following commands: grab help jar run test version ---- -NOTE: If you install the Spring Boot CLI by using Homebrew or MacPorts, the command-line -completion scripts are automatically registered with your shell. +NOTE: If you install the Spring Boot CLI by using Homebrew or MacPorts, the command-line completion scripts are automatically registered with your shell. [[getting-started-scoop-cli-installation]] ==== Windows Scoop Installation -If you are on a Windows and use https://scoop.sh/[Scoop], you can install the Spring Boot -CLI by using the following commands: +If you are on a Windows and use https://scoop.sh/[Scoop], you can install the Spring Boot CLI by using the following commands: [indent=0] ---- @@ -377,8 +338,8 @@ In that case, run `scoop update` and try again. [[getting-started-cli-example]] ==== Quick-start Spring CLI Example -You can use the following web application to test your installation. To start, create a -file called `app.groovy`, as follows: +You can use the following web application to test your installation. +To start, create a file called `app.groovy`, as follows: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -403,8 +364,8 @@ Then run it from a shell, as follows: NOTE: The first run of your application is slow, as dependencies are downloaded. Subsequent runs are much quicker. -Open `http://localhost:8080` in your favorite web browser. You should see the following -output: +Open `http://localhost:8080` in your favorite web browser. +You should see the following output: [indent=0] ---- @@ -415,16 +376,12 @@ output: [[getting-started-upgrading-from-an-earlier-version]] === Upgrading from an Earlier Version of Spring Boot -If you are upgrading from an earlier release of Spring Boot, check the -{github-wiki}/Spring-Boot-2.0-Migration-Guide["`migration guide`" on the project wiki] -that provides detailed upgrade instructions. Check also the -{github-wiki}["`release notes`"] for a list of "`new and noteworthy`" features for each -release. +If you are upgrading from the `1.x` release of Spring Boot, check the {github-wiki}/Spring-Boot-2.0-Migration-Guide["`migration guide`" on the project wiki] that provides detailed upgrade instructions. +Check also the {github-wiki}["`release notes`"] for a list of "`new and noteworthy`" features for each release. When upgrading to a new feature release, some properties may have been renamed or removed. -Spring Boot provides a way to analyze your application's environment and print diagnostics -at startup, but also temporarily migrate properties at runtime for you. To enable that -feature, add the following dependency to your project: +Spring Boot provides a way to analyze your application's environment and print diagnostics at startup, but also temporarily migrate properties at runtime for you. +To enable that feature, add the following dependency to your project: [source,xml,indent=0] ---- @@ -435,40 +392,31 @@ feature, add the following dependency to your project: ---- -WARNING: Properties that are added late to the environment, such as when using -`@PropertySource`, will not be taken into account. +WARNING: Properties that are added late to the environment, such as when using `@PropertySource`, will not be taken into account. -NOTE: Once you're done with the migration, please make sure to remove this module from -your project's dependencies. +NOTE: Once you're done with the migration, please make sure to remove this module from your project's dependencies. -To upgrade an existing CLI installation, use the appropriate package manager command (for -example, `brew upgrade`) or, if you manually installed the CLI, follow the -<>, remembering to update -your `PATH` environment variable to remove any older references. +To upgrade an existing CLI installation, use the appropriate package manager command (for example, `brew upgrade`). +If you manually installed the CLI, follow the <>, remembering to update your `PATH` environment variable to remove any older references. [[getting-started-first-application]] == Developing Your First Spring Boot Application -This section describes how to develop a simple "`Hello World!`" web application that -highlights some of Spring Boot's key features. We use Maven to build this project, since -most IDEs support it. +This section describes how to develop a simple "`Hello World!`" web application that highlights some of Spring Boot's key features. +We use Maven to build this project, since most IDEs support it. [TIP] ==== -The https://spring.io[spring.io] web site contains many "`Getting Started`" -https://spring.io/guides[guides] that use Spring Boot. If you need to solve a specific -problem, check there first. +The https://spring.io[spring.io] web site contains many "`Getting Started`" https://spring.io/guides[guides] that use Spring Boot. +If you need to solve a specific problem, check there first. -You can shortcut the steps below by going to https://start.spring.io and choosing the -"Web" starter from the dependencies searcher. Doing so generates a new project structure -so that you can <>. Check -the {spring-initializr-reference}/#user-guide[Spring Initializr documentation] for more -details. +You can shortcut the steps below by going to https://start.spring.io and choosing the "Web" starter from the dependencies searcher. +Doing so generates a new project structure so that you can <>. +Check the {spring-initializr-reference}/#user-guide[Spring Initializr documentation] for more details. ==== -Before we begin, open a terminal and run the following commands to ensure that you have -valid versions of Java and Maven installed: +Before we begin, open a terminal and run the following commands to ensure that you have valid versions of Java and Maven installed: [indent=0] ---- @@ -486,15 +434,16 @@ valid versions of Java and Maven installed: Java version: 1.8.0_102, vendor: Oracle Corporation ---- -NOTE: This sample needs to be created in its own folder. Subsequent instructions assume -that you have created a suitable folder and that it is your current directory. +NOTE: This sample needs to be created in its own folder. +Subsequent instructions assume that you have created a suitable folder and that it is your current directory. [[getting-started-first-application-pom]] === Creating the POM -We need to start by creating a Maven `pom.xml` file. The `pom.xml` is the recipe that is -used to build your project. Open your favorite text editor and add the following: +We need to start by creating a Maven `pom.xml` file. +The `pom.xml` is the recipe that is used to build your project. +Open your favorite text editor and add the following: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -542,29 +491,24 @@ endif::[] ---- -The preceding listing should give you a working build. You can test it by running `mvn -package` (for now, you can ignore the "`jar will be empty - no content was marked for -inclusion!`" warning). +The preceding listing should give you a working build. +You can test it by running `mvn package` (for now, you can ignore the "`jar will be empty - no content was marked for inclusion!`" warning). -NOTE: At this point, you could import the project into an IDE (most modern Java IDEs -include built-in support for Maven). For simplicity, we continue to use a plain text -editor for this example. +NOTE: At this point, you could import the project into an IDE (most modern Java IDEs include built-in support for Maven). +For simplicity, we continue to use a plain text editor for this example. [[getting-started-first-application-dependencies]] === Adding Classpath Dependencies Spring Boot provides a number of "`Starters`" that let you add jars to your classpath. -Our sample application has already used `spring-boot-starter-parent` in the `parent` -section of the POM. The `spring-boot-starter-parent` is a special starter that provides -useful Maven defaults. It also provides a -<> -section so that you can omit `version` tags for "`blessed`" dependencies. +Our sample application has already used `spring-boot-starter-parent` in the `parent` section of the POM. +The `spring-boot-starter-parent` is a special starter that provides useful Maven defaults. +It also provides a <> section so that you can omit `version` tags for "`blessed`" dependencies. -Other "`Starters`" provide dependencies that you are likely to need when developing a -specific type of application. Since we are developing a web application, we add a -`spring-boot-starter-web` dependency. Before that, we can look at what we currently have -by running the following command: +Other "`Starters`" provide dependencies that you are likely to need when developing a specific type of application. +Since we are developing a web application, we add a `spring-boot-starter-web` dependency. +Before that, we can look at what we currently have by running the following command: [indent=0] ---- @@ -573,10 +517,9 @@ by running the following command: [INFO] com.example:myproject:jar:0.0.1-SNAPSHOT ---- -The `mvn dependency:tree` command prints a tree representation of your project -dependencies. You can see that `spring-boot-starter-parent` provides no dependencies by -itself. To add the necessary dependencies, edit your `pom.xml` and add the -`spring-boot-starter-web` dependency immediately below the `parent` section: +The `mvn dependency:tree` command prints a tree representation of your project dependencies. +You can see that `spring-boot-starter-parent` provides no dependencies by itself. +To add the necessary dependencies, edit your `pom.xml` and add the `spring-boot-starter-web` dependency immediately below the `parent` section: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -588,16 +531,14 @@ itself. To add the necessary dependencies, edit your `pom.xml` and add the ---- -If you run `mvn dependency:tree` again, you see that there are now a number of additional -dependencies, including the Tomcat web server and Spring Boot itself. +If you run `mvn dependency:tree` again, you see that there are now a number of additional dependencies, including the Tomcat web server and Spring Boot itself. [[getting-started-first-application-code]] === Writing the Code -To finish our application, we need to create a single Java file. By default, Maven -compiles sources from `src/main/java`, so you need to create that folder structure and -then add a file named `src/main/java/Example.java` to contain the following code: +To finish our application, we need to create a single Java file. +By default, Maven compiles sources from `src/main/java`, so you need to create that folder structure and then add a file named `src/main/java/Example.java` to contain the following code: [source,java,indent=0] ---- @@ -621,64 +562,59 @@ then add a file named `src/main/java/Example.java` to contain the following code } ---- -Although there is not much code here, quite a lot is going on. We step through the -important parts in the next few sections. +Although there is not much code here, quite a lot is going on. +We step through the important parts in the next few sections. [[getting-started-first-application-annotations]] ==== The @RestController and @RequestMapping Annotations -The first annotation on our `Example` class is `@RestController`. This is known as a -_stereotype_ annotation. It provides hints for people reading the code and for Spring -that the class plays a specific role. In this case, our class is a web `@Controller`, so -Spring considers it when handling incoming web requests. +The first annotation on our `Example` class is `@RestController`. +This is known as a _stereotype_ annotation. +It provides hints for people reading the code and for Spring that the class plays a specific role. +In this case, our class is a web `@Controller`, so Spring considers it when handling incoming web requests. -The `@RequestMapping` annotation provides "`routing`" information. It tells Spring that -any HTTP request with the `/` path should be mapped to the `home` method. The -`@RestController` annotation tells Spring to render the resulting string directly back to -the caller. +The `@RequestMapping` annotation provides "`routing`" information. +It tells Spring that any HTTP request with the `/` path should be mapped to the `home` method. +The `@RestController` annotation tells Spring to render the resulting string directly back to the caller. -TIP: The `@RestController` and `@RequestMapping` annotations are Spring MVC annotations. -(They are not specific to Spring Boot.) See the {spring-reference}web.html#mvc[MVC -section] in the Spring Reference Documentation for more details. +TIP: The `@RestController` and `@RequestMapping` annotations are Spring MVC annotations (they are not specific to Spring Boot). +See the {spring-reference}web.html#mvc[MVC section] in the Spring Reference Documentation for more details. [[getting-started-first-application-auto-configuration]] ==== The @EnableAutoConfiguration Annotation -The second class-level annotation is `@EnableAutoConfiguration`. This annotation tells -Spring Boot to "`guess`" how you want to configure Spring, based on the jar dependencies -that you have added. Since `spring-boot-starter-web` added Tomcat and Spring MVC, the -auto-configuration assumes that you are developing a web application and sets up Spring -accordingly. +The second class-level annotation is `@EnableAutoConfiguration`. +This annotation tells Spring Boot to "`guess`" how you want to configure Spring, based on the jar dependencies that you have added. +Since `spring-boot-starter-web` added Tomcat and Spring MVC, the auto-configuration assumes that you are developing a web application and sets up Spring accordingly. .Starters and Auto-configuration **** -Auto-configuration is designed to work well with "`Starters`", but the two concepts are -not directly tied. You are free to pick and choose jar dependencies outside of the -starters. Spring Boot still does its best to auto-configure your application. +Auto-configuration is designed to work well with "`Starters`", but the two concepts are not directly tied. +You are free to pick and choose jar dependencies outside of the starters. +Spring Boot still does its best to auto-configure your application. **** [[getting-started-first-application-main-method]] ==== The "`main`" Method -The final part of our application is the `main` method. This is just a standard method -that follows the Java convention for an application entry point. Our main method -delegates to Spring Boot's `SpringApplication` class by calling `run`. -`SpringApplication` bootstraps our application, starting Spring, which, in turn, starts -the auto-configured Tomcat web server. We need to pass `Example.class` as an argument to -the `run` method to tell `SpringApplication` which is the primary Spring component. The -`args` array is also passed through to expose any command-line arguments. +The final part of our application is the `main` method. +This is just a standard method that follows the Java convention for an application entry point. +Our main method delegates to Spring Boot's `SpringApplication` class by calling `run`. +`SpringApplication` bootstraps our application, starting Spring, which, in turn, starts the auto-configured Tomcat web server. +We need to pass `Example.class` as an argument to the `run` method to tell `SpringApplication` which is the primary Spring component. +The `args` array is also passed through to expose any command-line arguments. [[getting-started-first-application-run]] === Running the Example -At this point, your application should work. Since you used the -`spring-boot-starter-parent` POM, you have a useful `run` goal that you can use to start -the application. Type `mvn spring-boot:run` from the root project directory to start the -application. You should see output similar to the following: +At this point, your application should work. +Since you used the `spring-boot-starter-parent` POM, you have a useful `run` goal that you can use to start the application. +Type `mvn spring-boot:run` from the root project directory to start the application. +You should see output similar to the following: [indent=0,subs="attributes"] ---- @@ -710,29 +646,24 @@ To gracefully exit the application, press `ctrl-c`. [[getting-started-first-application-executable-jar]] === Creating an Executable Jar -We finish our example by creating a completely self-contained executable jar file that -we could run in production. Executable jars (sometimes called "`fat jars`") are archives -containing your compiled classes along with all of the jar dependencies that your code -needs to run. +We finish our example by creating a completely self-contained executable jar file that we could run in production. +Executable jars (sometimes called "`fat jars`") are archives containing your compiled classes along with all of the jar dependencies that your code needs to run. .Executable jars and Java **** -Java does not provide a standard way to load nested jar files (jar files that are -themselves contained within a jar). This can be problematic if you are looking to -distribute a self-contained application. +Java does not provide a standard way to load nested jar files (jar files that are themselves contained within a jar). +This can be problematic if you are looking to distribute a self-contained application. -To solve this problem, many developers use "`uber`" jars. An uber jar packages all the -classes from all the application's dependencies into a single archive. The problem with -this approach is that it becomes hard to see which libraries are in your application. It -can also be problematic if the same filename is used (but with different content) in -multiple jars. +To solve this problem, many developers use "`uber`" jars. +An uber jar packages all the classes from all the application's dependencies into a single archive. +The problem with this approach is that it becomes hard to see which libraries are in your application. +It can also be problematic if the same filename is used (but with different content) in multiple jars. -Spring Boot takes a <> and lets you actually nest jars directly. +Spring Boot takes a <> and lets you actually nest jars directly. **** -To create an executable jar, we need to add the `spring-boot-maven-plugin` to our -`pom.xml`. To do so, insert the following lines just below the `dependencies` section: +To create an executable jar, we need to add the `spring-boot-maven-plugin` to our `pom.xml`. +To do so, insert the following lines just below the `dependencies` section: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -746,10 +677,9 @@ To create an executable jar, we need to add the `spring-boot-maven-plugin` to ou ---- -NOTE: The `spring-boot-starter-parent` POM includes `` configuration to bind -the `repackage` goal. If you do not use the parent POM, you need to declare this -configuration yourself. See the {spring-boot-maven-plugin-site}/usage.html[plugin -documentation] for details. +NOTE: The `spring-boot-starter-parent` POM includes `` configuration to bind the `repackage` goal. +If you do not use the parent POM, you need to declare this configuration yourself. +See the {spring-boot-maven-plugin-site}/usage.html[plugin documentation] for details. Save your `pom.xml` and run `mvn package` from the command line, as follows: @@ -772,18 +702,17 @@ Save your `pom.xml` and run `mvn package` from the command line, as follows: [INFO] ------------------------------------------------------------------------ ---- -If you look in the `target` directory, you should see `myproject-0.0.1-SNAPSHOT.jar`. The -file should be around 10 MB in size. If you want to peek inside, you can use `jar tvf`, -as follows: +If you look in the `target` directory, you should see `myproject-0.0.1-SNAPSHOT.jar`. +The file should be around 10 MB in size. +If you want to peek inside, you can use `jar tvf`, as follows: [indent=0] ---- $ jar tvf target/myproject-0.0.1-SNAPSHOT.jar ---- -You should also see a much smaller file named `myproject-0.0.1-SNAPSHOT.jar.original` in -the `target` directory. This is the original jar file that Maven created before it was -repackaged by Spring Boot. +You should also see a much smaller file named `myproject-0.0.1-SNAPSHOT.jar.original` in the `target` directory. +This is the original jar file that Maven created before it was repackaged by Spring Boot. To run that application, use the `java -jar` command, as follows: @@ -810,18 +739,12 @@ As before, to exit the application, press `ctrl-c`. [[getting-started-whats-next]] == What to Read Next -Hopefully, this section provided some of the Spring Boot basics and got you on your way -to writing your own applications. If you are a task-oriented type of developer, you might -want to jump over to https://spring.io and check out some of the -https://spring.io/guides/[getting started] guides that solve specific "`How do I do that -with Spring?`" problems. We also have Spring Boot-specific -"`<>`" reference documentation. +Hopefully, this section provided some of the Spring Boot basics and got you on your way to writing your own applications. +If you are a task-oriented type of developer, you might want to jump over to https://spring.io and check out some of the https://spring.io/guides/[getting started] guides that solve specific "`How do I do that with Spring?`" problems. +We also have Spring Boot-specific "`<>`" reference documentation. -The https://github.com/{github-repo}[Spring Boot repository] also has a -{github-code}/spring-boot-samples[bunch of samples] you can run. The samples are -independent of the rest of the code (that is, you do not need to build the rest to run or -use the samples). +The https://github.com/{github-repo}[Spring Boot repository] also has a {github-code}/spring-boot-samples[bunch of samples] you can run. +The samples are independent of the rest of the code (that is, you do not need to build the rest to run or use the samples). -Otherwise, the next logical step is to read _<>_. If -you are really impatient, you could also jump ahead and read about -_<>_. +Otherwise, the next logical step is to read _<>_. +If you are really impatient, you could also jump ahead and read about _<>_. diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/howto.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/howto.adoc index 32efb03f9ac..080d162ef3b 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/howto.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/howto.adoc @@ -3,41 +3,33 @@ [partintro] -- -This section provides answers to some common '`how do I do that...`' questions -that often arise when using Spring Boot. Its coverage is not exhaustive, but it -does cover quite a lot. +This section provides answers to some common '`how do I do that...`' questions that often arise when using Spring Boot. +Its coverage is not exhaustive, but it does cover quite a lot. -If you have a specific problem that we do not cover here, you might want to check out -https://stackoverflow.com/tags/spring-boot[stackoverflow.com] to see if someone has -already provided an answer. This is also a great place to ask new questions (please use -the `spring-boot` tag). +If you have a specific problem that we do not cover here, you might want to check out https://stackoverflow.com/tags/spring-boot[stackoverflow.com] to see if someone has already provided an answer. +This is also a great place to ask new questions (please use the `spring-boot` tag). -We are also more than happy to extend this section. If you want to add a '`how-to`', -send us a {github-code}[pull request]. +We are also more than happy to extend this section. +If you want to add a '`how-to`', send us a {github-code}[pull request]. -- [[howto-spring-boot-application]] == Spring Boot Application - This section includes topics relating directly to Spring Boot applications. [[howto-failure-analyzer]] === Create Your Own FailureAnalyzer -{dc-spring-boot}/diagnostics/FailureAnalyzer.{dc-ext}[`FailureAnalyzer`] is a great way -to intercept an exception on startup and turn it into a human-readable message, wrapped -in a {dc-spring-boot}/diagnostics/FailureAnalysis.{dc-ext}[`FailureAnalysis`]. Spring -Boot provides such an analyzer for application-context-related exceptions, JSR-303 -validations, and more. You can also create your own. +{dc-spring-boot}/diagnostics/FailureAnalyzer.{dc-ext}[`FailureAnalyzer`] is a great way to intercept an exception on startup and turn it into a human-readable message, wrapped in a {dc-spring-boot}/diagnostics/FailureAnalysis.{dc-ext}[`FailureAnalysis`]. +Spring Boot provides such an analyzer for application-context-related exceptions, JSR-303 validations, and more. +You can also create your own. -`AbstractFailureAnalyzer` is a convenient extension of `FailureAnalyzer` that checks the -presence of a specified exception type in the exception to handle. You can extend from -that so that your implementation gets a chance to handle the exception only when it is -actually present. If, for whatever reason, you cannot handle the exception, return `null` -to give another implementation a chance to handle the exception. +`AbstractFailureAnalyzer` is a convenient extension of `FailureAnalyzer` that checks the presence of a specified exception type in the exception to handle. +You can extend from that so that your implementation gets a chance to handle the exception only when it is actually present. +If, for whatever reason, you cannot handle the exception, return `null` to give another implementation a chance to handle the exception. `FailureAnalyzer` implementations must be registered in `META-INF/spring.factories`. The following example registers `ProjectConstraintViolationFailureAnalyzer`: @@ -48,144 +40,111 @@ The following example registers `ProjectConstraintViolationFailureAnalyzer`: com.example.ProjectConstraintViolationFailureAnalyzer ---- -NOTE: If you need access to the `BeanFactory` or the `Environment`, your `FailureAnalyzer` -can simply implement `BeanFactoryAware` or `EnvironmentAware` respectively. +NOTE: If you need access to the `BeanFactory` or the `Environment`, your `FailureAnalyzer` can simply implement `BeanFactoryAware` or `EnvironmentAware` respectively. [[howto-troubleshoot-auto-configuration]] === Troubleshoot Auto-configuration -The Spring Boot auto-configuration tries its best to "`do the right thing`", but -sometimes things fail, and it can be hard to tell why. +The Spring Boot auto-configuration tries its best to "`do the right thing`", but sometimes things fail, and it can be hard to tell why. -There is a really useful `ConditionEvaluationReport` available in any Spring Boot -`ApplicationContext`. You can see it if you enable `DEBUG` logging output. If you use -the `spring-boot-actuator` (see <>), -there is also a `conditions` endpoint that renders the report in JSON. Use that endpoint -to debug the application and see what features have been added (and which have not been -added) by Spring Boot at runtime. +There is a really useful `ConditionEvaluationReport` available in any Spring Boot `ApplicationContext`. +You can see it if you enable `DEBUG` logging output. +If you use the `spring-boot-actuator` (see <>), there is also a `conditions` endpoint that renders the report in JSON. +Use that endpoint to debug the application and see what features have been added (and which have not been added) by Spring Boot at runtime. -Many more questions can be answered by looking at the source code and the Javadoc. When -reading the code, remember the following rules of thumb: +Many more questions can be answered by looking at the source code and the Javadoc. +When reading the code, remember the following rules of thumb: -* Look for classes called `+*AutoConfiguration+` and read their sources. Pay special -attention to the `+@Conditional*+` annotations to find out what features they enable and -when. Add `--debug` to the command line or a System property `-Ddebug` to get a log on the -console of all the auto-configuration decisions that were made in your app. In a running -Actuator app, look at the `conditions` endpoint (`/actuator/conditions` or the JMX -equivalent) for the same information. -* Look for classes that are `@ConfigurationProperties` (such as -{sc-spring-boot-autoconfigure}/web/ServerProperties.{sc-ext}[`ServerProperties`]) -and read from there the available external configuration options. The -`@ConfigurationProperties` annotation has a `name` attribute that acts as a prefix to -external properties. Thus, `ServerProperties` has `prefix="server"` and its configuration -properties are `server.port`, `server.address`, and others. In a running Actuator app, -look at the `configprops` endpoint. -* Look for uses of the `bind` method on the `Binder` to pull configuration values -explicitly out of the `Environment` in a relaxed manner. It is often used with a prefix. +* Look for classes called `+*AutoConfiguration+` and read their sources. + Pay special attention to the `+@Conditional*+` annotations to find out what features they enable and when. + Add `--debug` to the command line or a System property `-Ddebug` to get a log on the console of all the auto-configuration decisions that were made in your app. + In a running application with actuator enabled, look at the `conditions` endpoint (`/actuator/conditions` or the JMX equivalent) for the same information. +* Look for classes that are `@ConfigurationProperties` (such as {sc-spring-boot-autoconfigure}/web/ServerProperties.{sc-ext}[`ServerProperties`]) and read from there the available external configuration options. + The `@ConfigurationProperties` annotation has a `name` attribute that acts as a prefix to external properties. + Thus, `ServerProperties` has `prefix="server"` and its configuration properties are `server.port`, `server.address`, and others. + In a running application with actuator enabled, look at the `configprops` endpoint. +* Look for uses of the `bind` method on the `Binder` to pull configuration values explicitly out of the `Environment` in a relaxed manner. + It is often used with a prefix. * Look for `@Value` annotations that bind directly to the `Environment`. -* Look for `@ConditionalOnExpression` annotations that switch features on and off in -response to SpEL expressions, normally evaluated with placeholders resolved from the -`Environment`. +* Look for `@ConditionalOnExpression` annotations that switch features on and off in response to SpEL expressions, normally evaluated with placeholders resolved from the `Environment`. [[howto-customize-the-environment-or-application-context]] === Customize the Environment or ApplicationContext Before It Starts -A `SpringApplication` has `ApplicationListeners` and `ApplicationContextInitializers` that -are used to apply customizations to the context or environment. Spring Boot loads a number -of such customizations for use internally from `META-INF/spring.factories`. There is more -than one way to register additional customizations: +A `SpringApplication` has `ApplicationListeners` and `ApplicationContextInitializers` that are used to apply customizations to the context or environment. +Spring Boot loads a number of such customizations for use internally from `META-INF/spring.factories`. +There is more than one way to register additional customizations: -* Programmatically, per application, by calling the `addListeners` and `addInitializers` -methods on `SpringApplication` before you run it. -* Declaratively, per application, by setting the `context.initializer.classes` or -`context.listener.classes` properties. -* Declaratively, for all applications, by adding a `META-INF/spring.factories` and packaging -a jar file that the applications all use as a library. +* Programmatically, per application, by calling the `addListeners` and `addInitializers` methods on `SpringApplication` before you run it. +* Declaratively, per application, by setting the `context.initializer.classes` or `context.listener.classes` properties. +* Declaratively, for all applications, by adding a `META-INF/spring.factories` and packaging a jar file that the applications all use as a library. -The `SpringApplication` sends some special `ApplicationEvents` to the listeners (some -even before the context is created) and then registers the listeners for events published -by the `ApplicationContext` as well. See -"`<>`" in the -'`Spring Boot features`' section for a complete list. +The `SpringApplication` sends some special `ApplicationEvents` to the listeners (some even before the context is created) and then registers the listeners for events published by the `ApplicationContext` as well. +See "`<>`" in the '`Spring Boot features`' section for a complete list. -It is also possible to customize the `Environment` before the application context is -refreshed by using `EnvironmentPostProcessor`. Each implementation should be registered in -`META-INF/spring.factories`, as shown in the following example: +It is also possible to customize the `Environment` before the application context is refreshed by using `EnvironmentPostProcessor`. +Each implementation should be registered in `META-INF/spring.factories`, as shown in the following example: [source,properties,indent=0] ---- org.springframework.boot.env.EnvironmentPostProcessor=com.example.YourEnvironmentPostProcessor ---- -The implementation can load arbitrary files and add them to the `Environment`. For -instance, the following example loads a YAML configuration file from the classpath: - +The implementation can load arbitrary files and add them to the `Environment`. +For instance, the following example loads a YAML configuration file from the classpath: [source,java,indent=0] ---- include::{code-examples}/context/EnvironmentPostProcessorExample.java[tag=example] ---- -TIP: The `Environment` has already been prepared with all the usual property sources -that Spring Boot loads by default. It is therefore possible to get the location of the -file from the environment. The preceding example adds the `custom-resource` property -source at the end of the list so that a key defined in any of the usual other locations -takes precedence. A custom implementation may define another order. +TIP: The `Environment` has already been prepared with all the usual property sources that Spring Boot loads by default. +It is therefore possible to get the location of the file from the environment. +The preceding example adds the `custom-resource` property source at the end of the list so that a key defined in any of the usual other locations takes precedence. +A custom implementation may define another order. -CAUTION: While using `@PropertySource` on your `@SpringBootApplication` may seem to be a -convenient and easy way to load a custom resource in the `Environment`, we do not -recommend it, because Spring Boot prepares the `Environment` before the -`ApplicationContext` is refreshed. Any key defined with `@PropertySource` is loaded too -late to have any effect on auto-configuration. +CAUTION: While using `@PropertySource` on your `@SpringBootApplication` may seem to be a convenient and easy way to load a custom resource in the `Environment`, we do not recommend it, because Spring Boot prepares the `Environment` before the `ApplicationContext` is refreshed. +Any key defined with `@PropertySource` is loaded too late to have any effect on auto-configuration. [[howto-build-an-application-context-hierarchy]] === Build an ApplicationContext Hierarchy (Adding a Parent or Root Context) -You can use the `ApplicationBuilder` class to create parent/child `ApplicationContext` -hierarchies. See "`<>`" -in the '`Spring Boot features`' section for more information. +You can use the `ApplicationBuilder` class to create parent/child `ApplicationContext` hierarchies. +See "`<>`" in the '`Spring Boot features`' section for more information. [[howto-create-a-non-web-application]] === Create a Non-web Application -Not all Spring applications have to be web applications (or web services). If you want to -execute some code in a `main` method but also bootstrap a Spring application to set up -the infrastructure to use, you can use the `SpringApplication` features of Spring -Boot. A `SpringApplication` changes its `ApplicationContext` class, depending on whether -it thinks it needs a web application or not. The first thing you can do to help it is to -leave server-related dependencies (e.g. servlet API) off the classpath. If you cannot do -that (for example, you run two applications from the same code base) then you can -explicitly call `setWebApplicationType(WebApplicationType.NONE)` on your -`SpringApplication` instance or set the `applicationContextClass` property (through the -Java API or with external properties). Application code that you want to run as your -business logic can be implemented as a `CommandLineRunner` and dropped into the context as -a `@Bean` definition. +Not all Spring applications have to be web applications (or web services). +If you want to execute some code in a `main` method but also bootstrap a Spring application to set up the infrastructure to use, you can use the `SpringApplication` features of Spring Boot. +A `SpringApplication` changes its `ApplicationContext` class, depending on whether it thinks it needs a web application or not. +The first thing you can do to help it is to leave server-related dependencies (e.g. servlet API) off the classpath. +If you cannot do that (for example, you run two applications from the same code base) then you can explicitly call `setWebApplicationType(WebApplicationType.NONE)` on your `SpringApplication` instance or set the `applicationContextClass` property (through the Java API or with external properties). +Application code that you want to run as your business logic can be implemented as a `CommandLineRunner` and dropped into the context as a `@Bean` definition. [[howto-properties-and-configuration]] == Properties and Configuration +This section includes topics about setting and reading properties and configuration settings and their interaction with Spring Boot applications. + -This section includes topics about setting and reading properties and configuration -settings and their interaction with Spring Boot applications. [[howto-automatic-expansion]] === Automatically Expand Properties at Build Time -Rather than hardcoding some properties that are also specified in your project's build -configuration, you can automatically expand them by instead using the existing build -configuration. This is possible in both Maven and Gradle. +Rather than hardcoding some properties that are also specified in your project's build configuration, you can automatically expand them by instead using the existing build configuration. +This is possible in both Maven and Gradle. [[howto-automatic-expansion-maven]] ==== Automatic Property Expansion Using Maven -You can automatically expand properties from the Maven project by using resource -filtering. If you use the `spring-boot-starter-parent`, you can then refer to your -Maven '`project properties`' with `@..@` placeholders, as shown in the following example: +You can automatically expand properties from the Maven project by using resource filtering. +If you use the `spring-boot-starter-parent`, you can then refer to your Maven '`project properties`' with `@..@` placeholders, as shown in the following example: [source,properties,indent=0] ---- @@ -193,17 +152,14 @@ Maven '`project properties`' with `@..@` placeholders, as shown in the following app.java.version=@java.version@ ---- -NOTE: Only production configuration is filtered that way (in other words, no filtering is -applied on `src/test/resources`). +NOTE: Only production configuration is filtered that way (in other words, no filtering is applied on `src/test/resources`). -TIP: If you enable the `addResources` flag, the `spring-boot:run` goal can add -`src/main/resources` directly to the classpath (for hot reloading purposes). Doing so -circumvents the resource filtering and this feature. Instead, you can use the `exec:java` -goal or customize the plugin's configuration. See the -{spring-boot-maven-plugin-site}/usage.html[plugin usage page] for more details. +TIP: If you enable the `addResources` flag, the `spring-boot:run` goal can add `src/main/resources` directly to the classpath (for hot reloading purposes). +Doing so circumvents the resource filtering and this feature. +Instead, you can use the `exec:java` goal or customize the plugin's configuration. +See the {spring-boot-maven-plugin-site}/usage.html[plugin usage page] for more details. -If you do not use the starter parent, you need to include the following element inside -the `` element of your `pom.xml`: +If you do not use the starter parent, you need to include the following element inside the `` element of your `pom.xml`: [source,xml,indent=0] ---- @@ -232,16 +188,14 @@ You also need to include the following element inside ``: ---- -NOTE: The `useDefaultDelimiters` property is important if you use standard Spring -placeholders (such as `$\{placeholder}`) in your configuration. If that property is not -set to `false`, these may be expanded by the build. +NOTE: The `useDefaultDelimiters` property is important if you use standard Spring placeholders (such as `$\{placeholder}`) in your configuration. +If that property is not set to `false`, these may be expanded by the build. [[howto-automatic-expansion-gradle]] ==== Automatic Property Expansion Using Gradle -You can automatically expand properties from the Gradle project by configuring the -Java plugin's `processResources` task to do so, as shown in the following example: +You can automatically expand properties from the Gradle project by configuring the Java plugin's `processResources` task to do so, as shown in the following example: [source,groovy,indent=0] ---- @@ -250,8 +204,7 @@ Java plugin's `processResources` task to do so, as shown in the following exampl } ---- -You can then refer to your Gradle project's properties by using placeholders, as shown in the -following example: +You can then refer to your Gradle project's properties by using placeholders, as shown in the following example: [source,properties,indent=0] ---- @@ -259,20 +212,16 @@ following example: app.description=${description} ---- -NOTE: Gradle's `expand` method uses Groovy's `SimpleTemplateEngine`, which transforms -`${..}` tokens. The `${..}` style conflicts with Spring's own property placeholder -mechanism. To use Spring property placeholders together with automatic expansion, escape -the Spring property placeholders as follows: `\${..}`. - +NOTE: Gradle's `expand` method uses Groovy's `SimpleTemplateEngine`, which transforms `${..}` tokens. The `${..}` style conflicts with Spring's own property placeholder mechanism. +To use Spring property placeholders together with automatic expansion, escape the Spring property placeholders as follows: `\${..}`. [[howto-externalize-configuration]] === Externalize the Configuration of `SpringApplication` -A `SpringApplication` has bean properties (mainly setters), so you can use its Java API as -you create the application to modify its behavior. Alternatively, you can externalize the -configuration by setting properties in `+spring.main.*+`. For example, in -`application.properties`, you might have the following settings: +A `SpringApplication` has bean properties (mainly setters), so you can use its Java API as you create the application to modify its behavior. +Alternatively, you can externalize the configuration by setting properties in `+spring.main.*+`. +For example, in `application.properties`, you might have the following settings: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -280,11 +229,9 @@ configuration by setting properties in `+spring.main.*+`. For example, in spring.main.banner-mode=off ---- -Then the Spring Boot banner is not printed on startup, and the application is not starting -an embedded web server. +Then the Spring Boot banner is not printed on startup, and the application is not starting an embedded web server. -Properties defined in external configuration override the values specified with the Java -API, with the notable exception of the sources used to create the `ApplicationContext`. +Properties defined in external configuration override the values specified with the Java API, with the notable exception of the sources used to create the `ApplicationContext`. Consider the following application: [source,java,indent=0] @@ -303,77 +250,55 @@ Now consider the following configuration: spring.main.banner-mode=console ---- -The actual application _now_ shows the banner (as overridden by configuration) and uses -three sources for the `ApplicationContext` (in the following order): `demo.MyApp`, -`com.acme.Config`, and `com.acme.ExtraConfig`. +The actual application _now_ shows the banner (as overridden by configuration) and uses three sources for the `ApplicationContext` (in the following order): `demo.MyApp`, `com.acme.Config`, and `com.acme.ExtraConfig`. [[howto-change-the-location-of-external-properties]] === Change the Location of External Properties of an Application -By default, properties from different sources are added to the Spring `Environment` in a -defined order (see "`<>`" in -the '`Spring Boot features`' section for the exact order). +By default, properties from different sources are added to the Spring `Environment` in a defined order (see "`<>`" in the '`Spring Boot features`' section for the exact order). -A nice way to augment and modify this ordering is to add `@PropertySource` annotations to your -application sources. Classes passed to the `SpringApplication` static convenience -methods and those added using `setSources()` are inspected to see if they have -`@PropertySources`. If they do, those properties are added to the `Environment` early -enough to be used in all phases of the `ApplicationContext` lifecycle. Properties added -in this way have lower priority than any added by using the default locations (such as -`application.properties`), system properties, environment variables, or the command line. +A nice way to augment and modify this ordering is to add `@PropertySource` annotations to your application sources. +Classes passed to the `SpringApplication` static convenience methods and those added using `setSources()` are inspected to see if they have `@PropertySources`. +If they do, those properties are added to the `Environment` early enough to be used in all phases of the `ApplicationContext` lifecycle. +Properties added in this way have lower priority than any added by using the default locations (such as `application.properties`), system properties, environment variables, or the command line. -You can also provide the following System properties (or environment variables) to change -the behavior: +You can also provide the following System properties (or environment variables) to change the behavior: -* `spring.config.name` (`SPRING_CONFIG_NAME`): Defaults to `application` as the root of -the file name. -* `spring.config.location` (`SPRING_CONFIG_LOCATION`): The file to load (such as a -classpath resource or a URL). A separate `Environment` property source is set up for this -document and it can be overridden by system properties, environment variables, or the -command line. +* `spring.config.name` (`SPRING_CONFIG_NAME`): Defaults to `application` as the root of the file name. +* `spring.config.location` (`SPRING_CONFIG_LOCATION`): The file to load (such as a classpath resource or a URL). + A separate `Environment` property source is set up for this document and it can be overridden by system properties, environment variables, or the command line. -No matter what you set in the environment, Spring Boot always loads -`application.properties` as described above. By default, if YAML is used, then files with -the '`.yml`' extension are also added to the list. +No matter what you set in the environment, Spring Boot always loads `application.properties` as described above. +By default, if YAML is used, then files with the '`.yml`' extension are also added to the list. -Spring Boot logs the configuration files that are loaded at the `DEBUG` level and the -candidates it has not found at `TRACE` level. +Spring Boot logs the configuration files that are loaded at the `DEBUG` level and the candidates it has not found at `TRACE` level. -See {sc-spring-boot}/context/config/ConfigFileApplicationListener.{sc-ext}[`ConfigFileApplicationListener`] -for more detail. +See {sc-spring-boot}/context/config/ConfigFileApplicationListener.{sc-ext}[`ConfigFileApplicationListener`] for more detail. [[howto-use-short-command-line-arguments]] === Use '`Short`' Command Line Arguments -Some people like to use (for example) `--port=9000` instead of `--server.port=9000` to -set configuration properties on the command line. You can enable this behavior by using -placeholders in `application.properties`, as shown in the following example: +Some people like to use (for example) `--port=9000` instead of `--server.port=9000` to set configuration properties on the command line. +You can enable this behavior by using placeholders in `application.properties`, as shown in the following example: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- server.port=${port:8080} ---- -TIP: If you inherit from the `spring-boot-starter-parent` POM, the default filter -token of the `maven-resources-plugins` has been changed from `+${*}+` to `@` (that is, -`@maven.token@` instead of `${maven.token}`) to prevent conflicts with Spring-style -placeholders. If you have enabled Maven filtering for the `application.properties` -directly, you may want to also change the default filter token to use -https://maven.apache.org/plugins/maven-resources-plugin/resources-mojo.html#delimiters[other -delimiters]. +TIP: If you inherit from the `spring-boot-starter-parent` POM, the default filter token of the `maven-resources-plugins` has been changed from `+${*}+` to `@` (that is, `@maven.token@` instead of `${maven.token}`) to prevent conflicts with Spring-style placeholders. +If you have enabled Maven filtering for the `application.properties` directly, you may want to also change the default filter token to use https://maven.apache.org/plugins/maven-resources-plugin/resources-mojo.html#delimiters[other delimiters]. -NOTE: In this specific case, the port binding works in a PaaS environment such as Heroku -or Cloud Foundry. In those two platforms, the `PORT` environment variable is set -automatically and Spring can bind to capitalized synonyms for `Environment` properties. +NOTE: In this specific case, the port binding works in a PaaS environment such as Heroku or Cloud Foundry. +In those two platforms, the `PORT` environment variable is set automatically and Spring can bind to capitalized synonyms for `Environment` properties. [[howto-use-yaml-for-external-properties]] === Use YAML for External Properties -YAML is a superset of JSON and, as such, is a convenient syntax for storing external -properties in a hierarchical format, as shown in the following example: +YAML is a superset of JSON and, as such, is a convenient syntax for storing external properties in a hierarchical format, as shown in the following example: [source,yaml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -388,11 +313,8 @@ properties in a hierarchical format, as shown in the following example: ---- Create a file called `application.yml` and put it in the root of your classpath. -Then add `snakeyaml` to your dependencies (Maven coordinates `org.yaml:snakeyaml`, already -included if you use the `spring-boot-starter`). A YAML file is parsed to a Java -`Map` (like a JSON object), and Spring Boot flattens the map so that it -is one level deep and has period-separated keys, as many people are used to with -`Properties` files in Java. +Then add `snakeyaml` to your dependencies (Maven coordinates `org.yaml:snakeyaml`, already included if you use the `spring-boot-starter`). +A YAML file is parsed to a Java `Map` (like a JSON object), and Spring Boot flattens the map so that it is one level deep and has period-separated keys, as many people are used to with `Properties` files in Java. The preceding example YAML corresponds to the following `application.properties` file: @@ -404,48 +326,40 @@ The preceding example YAML corresponds to the following `application.properties` server.port=9000 ---- -See "`<>`" in -the '`Spring Boot features`' section for more information -about YAML. +See "`<>`" in the '`Spring Boot features`' section for more information about YAML. + + [[howto-set-active-spring-profiles]] === Set the Active Spring Profiles -The Spring `Environment` has an API for this, but you would normally set a System property -(`spring.profiles.active`) or an OS environment variable (`SPRING_PROFILES_ACTIVE`). -Also, you can launch your application with a `-D` argument (remember to put it before the -main class or jar archive), as follows: +The Spring `Environment` has an API for this, but you would normally set a System property (`spring.profiles.active`) or an OS environment variable (`SPRING_PROFILES_ACTIVE`). +Also, you can launch your application with a `-D` argument (remember to put it before the main class or jar archive), as follows: [indent=0,subs="verbatim,quotes,attributes"] ---- $ java -jar -Dspring.profiles.active=production demo-0.0.1-SNAPSHOT.jar ---- -In Spring Boot, you can also set the active profile in `application.properties`, as shown -in the following example: +In Spring Boot, you can also set the active profile in `application.properties`, as shown in the following example: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- spring.profiles.active=production ---- -A value set this way is replaced by the System property or environment variable setting -but not by the `SpringApplicationBuilder.profiles()` method. Thus, the latter Java API can -be used to augment the profiles without changing the defaults. +A value set this way is replaced by the System property or environment variable setting but not by the `SpringApplicationBuilder.profiles()` method. +Thus, the latter Java API can be used to augment the profiles without changing the defaults. -See "`<>`" in -the "`Spring Boot features`" section for more information. +See "`<>`" in the "`Spring Boot features`" section for more information. [[howto-change-configuration-depending-on-the-environment]] === Change Configuration Depending on the Environment -A YAML file is actually a sequence of documents separated by `---` lines, and each -document is parsed separately to a flattened map. +A YAML file is actually a sequence of documents separated by `---` lines, and each document is parsed separately to a flattened map. -If a YAML document contains a `spring.profiles` key, then the profiles value -(a comma-separated list of profiles) is fed into the Spring -`Environment.acceptsProfiles()` method. If any of those profiles is active, that document -is included in the final merge (otherwise, it is not), as shown in the following example: +If a YAML document contains a `spring.profiles` key, then the profiles value (a comma-separated list of profiles) is fed into the Spring `Environment.acceptsProfiles()` method. +If any of those profiles is active, that document is included in the final merge (otherwise, it is not), as shown in the following example: [source,yaml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -466,58 +380,47 @@ is included in the final merge (otherwise, it is not), as shown in the following port: 0 ---- -In the preceding example, the default port is 9000. However, if the Spring profile called -'`development`' is active, then the port is 9001. If '`production`' is active, then the -port is 0. +In the preceding example, the default port is 9000. +However, if the Spring profile called '`development`' is active, then the port is 9001. +If '`production`' is active, then the port is 0. -NOTE: The YAML documents are merged in the order in which they are encountered. Later -values override earlier values. +NOTE: The YAML documents are merged in the order in which they are encountered. +Later values override earlier values. -To do the same thing with properties files, you can use -`application-$\{profile}.properties` to specify profile-specific values. +To do the same thing with properties files, you can use `application-$\{profile}.properties` to specify profile-specific values. [[howto-discover-build-in-options-for-external-properties]] === Discover Built-in Options for External Properties -Spring Boot binds external properties from `application.properties` (or `.yml` files and -other places) into an application at runtime. There is not (and technically cannot be) an -exhaustive list of all supported properties in a single location, because contributions -can come from additional jar files on your classpath. +Spring Boot binds external properties from `application.properties` (or `.yml` files and other places) into an application at runtime. +There is not (and technically cannot be) an exhaustive list of all supported properties in a single location, because contributions can come from additional jar files on your classpath. -A running application with the Actuator features has a `configprops` endpoint that shows -all the bound and bindable properties available through `@ConfigurationProperties`. +A running application with the Actuator features has a `configprops` endpoint that shows all the bound and bindable properties available through `@ConfigurationProperties`. -The appendix includes an <> example with a list of the most common properties supported by -Spring Boot. The definitive list comes from searching the source code for -`@ConfigurationProperties` and `@Value` annotations as well as the occasional use of -`Binder`. For more about the exact ordering of loading properties, see -"<>". +The appendix includes an <> example with a list of the most common properties supported by Spring Boot. +The definitive list comes from searching the source code for `@ConfigurationProperties` and `@Value` annotations as well as the occasional use of `Binder`. +For more about the exact ordering of loading properties, see "<>". [[howto-embedded-web-servers]] == Embedded Web Servers +Each Spring Boot web application includes an embedded web server. +This feature leads to a number of how-to questions, including how to change the embedded server and how to configure the embedded server. +This section answers those questions. + -Each Spring Boot web application includes an embedded web server. This feature leads to a -number of how-to questions, including how to change the embedded server and how to -configure the embedded server. This section answers those questions. [[howto-use-another-web-server]] === Use Another Web Server Many Spring Boot starters include default embedded containers. -* For servlet stack applications, the `spring-boot-starter-web` includes Tomcat by including -`spring-boot-starter-tomcat`, but you can use `spring-boot-starter-jetty` or -`spring-boot-starter-undertow` instead. -* For reactive stack applications, the `spring-boot-starter-webflux` includes Reactor Netty -by including `spring-boot-starter-reactor-netty`, but you can use `spring-boot-starter-tomcat`, -`spring-boot-starter-jetty`, or `spring-boot-starter-undertow` instead. +* For servlet stack applications, the `spring-boot-starter-web` includes Tomcat by including `spring-boot-starter-tomcat`, but you can use `spring-boot-starter-jetty` or `spring-boot-starter-undertow` instead. +* For reactive stack applications, the `spring-boot-starter-webflux` includes Reactor Netty by including `spring-boot-starter-reactor-netty`, but you can use `spring-boot-starter-tomcat`, `spring-boot-starter-jetty`, or `spring-boot-starter-undertow` instead. -When switching to a different HTTP server, you need to exclude the default dependencies -in addition to including the one you need. Spring Boot provides separate starters for -HTTP servers to help make this process as easy as possible. +When switching to a different HTTP server, you need to exclude the default dependencies in addition to including the one you need. +Spring Boot provides separate starters for HTTP servers to help make this process as easy as possible. The following Maven example shows how to exclude Tomcat and include Jetty for Spring MVC: @@ -544,11 +447,9 @@ The following Maven example shows how to exclude Tomcat and include Jetty for Sp ---- -NOTE: The version of the Servlet API has been overridden as, unlike Tomcat 9 and Undertow -2.0, Jetty 9.4 does not support Servlet 4.0. +NOTE: The version of the Servlet API has been overridden as, unlike Tomcat 9 and Undertow 2.0, Jetty 9.4 does not support Servlet 4.0. -The following Gradle example shows how to exclude Netty and include Undertow for Spring -WebFlux: +The following Gradle example shows how to exclude Netty and include Undertow for Spring WebFlux: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -565,17 +466,14 @@ WebFlux: } ---- -NOTE: `spring-boot-starter-reactor-netty` is required to use the `WebClient` class, so -you may need to keep a dependency on Netty even when you need to include a different HTTP -server. +NOTE: `spring-boot-starter-reactor-netty` is required to use the `WebClient` class, so you may need to keep a dependency on Netty even when you need to include a different HTTP server. [[howto-disable-web-server]] === Disabling the Web Server -If your classpath contains the necessary bits to start a web server, Spring Boot will -automatically start it. To disable this behaviour configure the `WebApplicationType` in -your `application.properties`, as shown in the following example: +If your classpath contains the necessary bits to start a web server, Spring Boot will automatically start it. +To disable this behavior configure the `WebApplicationType` in your `application.properties`, as shown in the following example: [source,properties,indent=0] ---- @@ -586,19 +484,12 @@ your `application.properties`, as shown in the following example: [[howto-change-the-http-port]] === Change the HTTP Port -In a standalone application, the main HTTP port defaults to `8080` but can be set with -`server.port` (for example, in `application.properties` or as a System property). Thanks -to relaxed binding of `Environment` values, you can also use `SERVER_PORT` (for example, -as an OS environment variable). +In a standalone application, the main HTTP port defaults to `8080` but can be set with `server.port` (for example, in `application.properties` or as a System property). +Thanks to relaxed binding of `Environment` values, you can also use `SERVER_PORT` (for example, as an OS environment variable). -To switch off the HTTP endpoints completely but still create a `WebApplicationContext`, -use `server.port=-1`. (Doing so is sometimes useful for testing.) +To switch off the HTTP endpoints completely but still create a `WebApplicationContext`, use `server.port=-1` (doing so is sometimes useful for testing). -For more details, see -"`<>`" -in the '`Spring Boot features`' section, or the -{sc-spring-boot-autoconfigure}/web/ServerProperties.{sc-ext}[`ServerProperties`] source -code. +For more details, see "`<>`" in the '`Spring Boot Features`' section, or the {sc-spring-boot-autoconfigure}/web/ServerProperties.{sc-ext}[`ServerProperties`] source code. @@ -610,15 +501,10 @@ To scan for a free port (using OS natives to prevent clashes) use `server.port=0 [[howto-discover-the-http-port-at-runtime]] === Discover the HTTP Port at Runtime -You can access the port the server is running on from log output or from the -`ServletWebServerApplicationContext` through its `WebServer`. The best way to get that and -be sure that it has been initialized is to add a `@Bean` of type -`ApplicationListener` and pull the container -out of the event when it is published. +You can access the port the server is running on from log output or from the `ServletWebServerApplicationContext` through its `WebServer`. +The best way to get that and be sure that it has been initialized is to add a `@Bean` of type `ApplicationListener` and pull the container out of the event when it is published. -Tests that use `@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)` can -also inject the actual port into a field by using the `@LocalServerPort` annotation, as -shown in the following example: +Tests that use `@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)` can also inject the actual port into a field by using the `@LocalServerPort` annotation, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -639,30 +525,28 @@ shown in the following example: [NOTE] ==== -`@LocalServerPort` is a meta-annotation for `@Value("${local.server.port}")`. Do not try -to inject the port in a regular application. As we just saw, the value is set only after -the container has been initialized. Contrary to a test, application code callbacks are -processed early (before the value is actually available). +`@LocalServerPort` is a meta-annotation for `@Value("${local.server.port}")`. +Do not try to inject the port in a regular application. +As we just saw, the value is set only after the container has been initialized. +Contrary to a test, application code callbacks are processed early (before the value is actually available). ==== [[how-to-enable-http-response-compression]] === Enable HTTP Response Compression -HTTP response compression is supported by Jetty, Tomcat, and Undertow. It can be enabled -in `application.properties`, as follows: +HTTP response compression is supported by Jetty, Tomcat, and Undertow. +It can be enabled in `application.properties`, as follows: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- server.compression.enabled=true ---- -By default, responses must be at least 2048 bytes in length for compression to be -performed. You can configure this behavior by setting the -`server.compression.min-response-size` property. +By default, responses must be at least 2048 bytes in length for compression to be performed. +You can configure this behavior by setting the `server.compression.min-response-size` property. -By default, responses are compressed only if their content type is one of the -following: +By default, responses are compressed only if their content type is one of the following: * `text/html` * `text/xml` @@ -679,9 +563,8 @@ You can configure this behavior by setting the `server.compression.mime-types` p [[howto-configure-ssl]] === Configure SSL -SSL can be configured declaratively by setting the various `+server.ssl.*+` properties, -typically in `application.properties` or `application.yml`. The following example shows -setting SSL properties in `application.properties`: +SSL can be configured declaratively by setting the various `+server.ssl.*+` properties, typically in `application.properties` or `application.yml`. +The following example shows setting SSL properties in `application.properties`: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -691,31 +574,25 @@ setting SSL properties in `application.properties`: server.ssl.key-password=another-secret ---- -See {sc-spring-boot}/web/server/Ssl.{sc-ext}[`Ssl`] for details of all of the -supported properties. +See {sc-spring-boot}/web/server/Ssl.{sc-ext}[`Ssl`] for details of all of the supported properties. -Using configuration such as the preceding example means the application no longer supports -a plain HTTP connector at port 8080. Spring Boot does not support the configuration of -both an HTTP connector and an HTTPS connector through `application.properties`. If you -want to have both, you need to configure one of them programmatically. We recommend using -`application.properties` to configure HTTPS, as the HTTP connector is the easier of the -two to configure programmatically. See the -{github-code}/spring-boot-samples/spring-boot-sample-tomcat-multi-connectors[`spring-boot-sample-tomcat-multi-connectors`] -sample project for an example. +Using configuration such as the preceding example means the application no longer supports a plain HTTP connector at port 8080. +Spring Boot does not support the configuration of both an HTTP connector and an HTTPS connector through `application.properties`. +If you want to have both, you need to configure one of them programmatically. +We recommend using `application.properties` to configure HTTPS, as the HTTP connector is the easier of the two to configure programmatically. +See the{github-code}/spring-boot-samples/spring-boot-sample-tomcat-multi-connectors[`spring-boot-sample-tomcat-multi-connectors`] sample project for an example. [[howto-configure-http2]] === Configure HTTP/2 -You can enable HTTP/2 support in your Spring Boot application with the -`+server.http2.enabled+` configuration property. This support depends on the chosen web -server and the application environment, since that protocol is not supported -out-of-the-box by JDK8. +You can enable HTTP/2 support in your Spring Boot application with the `+server.http2.enabled+` configuration property. +This support depends on the chosen web server and the application environment, since that protocol is not supported out-of-the-box by JDK8. [NOTE] ==== -Spring Boot does not support `h2c`, the cleartext version of the HTTP/2 protocol. So you -must <>. +Spring Boot does not support `h2c`, the cleartext version of the HTTP/2 protocol. +So you must <>. ==== @@ -728,23 +605,19 @@ As of Undertow 1.4.0+, HTTP/2 is supported without any additional requirement on [[howto-configure-http2-jetty]] ==== HTTP/2 with Jetty -As of Jetty 9.4.8, HTTP/2 is also supported with the -https://www.conscrypt.org/[Conscrypt library]. -To enable that support, your application needs to have two additional dependencies: -`org.eclipse.jetty:jetty-alpn-conscrypt-server` and `org.eclipse.jetty.http2:http2-server`. +As of Jetty 9.4.8, HTTP/2 is also supported with the https://www.conscrypt.org/[Conscrypt library]. +To enable that support, your application needs to have two additional dependencies: `org.eclipse.jetty:jetty-alpn-conscrypt-server` and `org.eclipse.jetty.http2:http2-server`. [[howto-configure-http2-tomcat]] ==== HTTP/2 with Tomcat -Spring Boot ships by default with Tomcat 9.0.x which supports HTTP/2 out of the box when -using JDK 9 or later. Alternatively, HTTP/2 can be used on JDK 8 if the `libtcnative` -library and its dependencies are installed on the host operating system. +Spring Boot ships by default with Tomcat 9.0.x which supports HTTP/2 out of the box when using JDK 9 or later. +Alternatively, HTTP/2 can be used on JDK 8 if the `libtcnative` library and its dependencies are installed on the host operating system. -The library folder must be made available, if not already, to the JVM library path. You -can do so with a JVM argument such as -`-Djava.library.path=/usr/local/opt/tomcat-native/lib`. More on this in the -https://tomcat.apache.org/tomcat-9.0-doc/apr.html[official Tomcat documentation]. +The library folder must be made available, if not already, to the JVM library path. +You can do so with a JVM argument such as `-Djava.library.path=/usr/local/opt/tomcat-native/lib`. +More on this in the https://tomcat.apache.org/tomcat-9.0-doc/apr.html[official Tomcat documentation]. Starting Tomcat 9.0.x on JDK 8 without that native support logs the following error: @@ -761,36 +634,22 @@ This error is not fatal, and the application still starts with HTTP/1.1 SSL supp ==== HTTP/2 with Reactor Netty The `spring-boot-webflux-starter` is using by default Reactor Netty as a server. Reactor Netty can be configured for HTTP/2 using the JDK support with JDK 9 or later. -For JDK 8 environments, or for optimal runtime performance, this server also supports -HTTP/2 with native libraries. To enable that, your application needs to have an -additional dependency. +For JDK 8 environments, or for optimal runtime performance, this server also supports HTTP/2 with native libraries. +To enable that, your application needs to have an additional dependency. -Spring Boot manages the version for the -`io.netty:netty-tcnative-boringssl-static` "uber jar", containing native libraries for -all platforms. Developers can choose to import only the required dependencies using -a classifier (see https://netty.io/wiki/forked-tomcat-native.html[the Netty official -documentation]). +Spring Boot manages the version for the `io.netty:netty-tcnative-boringssl-static` "uber jar", containing native libraries for all platforms. +Developers can choose to import only the required dependencies using a classifier (see https://netty.io/wiki/forked-tomcat-native.html[the Netty official documentation]). [[howto-configure-webserver]] === Configure the Web Server - -Generally, you should first consider using one of the many available configuration keys -and customize your web server by adding new entries in your `application.properties` (or -`application.yml`, or environment, etc. see -"`<>`"). The `server.{asterisk}` -namespace is quite useful here, and it includes namespaces like `server.tomcat.{asterisk}`, -`server.jetty.{asterisk}` and others, for server-specific features. +Generally, you should first consider using one of the many available configuration keys and customize your web server by adding new entries in your `application.properties` (or `application.yml`, or environment, etc. see "`<>`"). +The `server.{asterisk}` namespace is quite useful here, and it includes namespaces like `server.tomcat.{asterisk}`, `server.jetty.{asterisk}` and others, for server-specific features. See the list of <>. -The previous sections covered already many common use cases, such as compression, SSL -or HTTP/2. However, if a configuration key doesn't exist for your use case, you should -then look at -{dc-spring-boot}/web/server/WebServerFactoryCustomizer.html[`WebServerFactoryCustomizer`]. -You can declare such a component and get access to the server factory relevant to your -choice: you should select the variant for the chosen Server (Tomcat, Jetty, Reactor Netty, -Undertow) and the chosen web stack (Servlet or Reactive). +The previous sections covered already many common use cases, such as compression, SSL or HTTP/2. However, if a configuration key doesn't exist for your use case, you should then look at {dc-spring-boot}/web/server/WebServerFactoryCustomizer.html[`WebServerFactoryCustomizer`]. +You can declare such a component and get access to the server factory relevant to your choice: you should select the variant for the chosen Server (Tomcat, Jetty, Reactor Netty, Undertow) and the chosen web stack (Servlet or Reactive). The example below is for Tomcat with the `spring-boot-starter-web` (Servlet stack): @@ -829,24 +688,18 @@ In addition Spring Boot provides: | Reactor | N/A | `NettyReactiveWebServerFactory` - |=== -Once you've got access to a `WebServerFactory`, you can often add customizers to it to -configure specific parts, like connectors, server resources, or the server itself - all -using server-specific APIs. +Once you've got access to a `WebServerFactory`, you can often add customizers to it to configure specific parts, like connectors, server resources, or the server itself - all using server-specific APIs. -As a last resort, you can also declare your own `WebServerFactory` component, which will -override the one provided by Spring Boot. In this case, you can't rely on configuration -properties in the `server` namespace anymore. +As a last resort, you can also declare your own `WebServerFactory` component, which will override the one provided by Spring Boot. +In this case, you can't rely on configuration properties in the `server` namespace anymore. [[howto-add-a-servlet-filter-or-listener]] === Add a Servlet, Filter, or Listener to an Application -In a servlet stack application, i.e. with the `spring-boot-starter-web`, there are two -ways to add `Servlet`, `Filter`, `ServletContextListener`, and the other listeners -supported by the Servlet API to your application: +In a servlet stack application, i.e. with the `spring-boot-starter-web`, there are two ways to add `Servlet`, `Filter`, `ServletContextListener`, and the other listeners supported by the Servlet API to your application: * <> * <> @@ -855,38 +708,28 @@ supported by the Servlet API to your application: [[howto-add-a-servlet-filter-or-listener-as-spring-bean]] ==== Add a Servlet, Filter, or Listener by Using a Spring Bean -To add a `Servlet`, `Filter`, or Servlet `*Listener` by using a Spring bean, you must -provide a `@Bean` definition for it. Doing so can be very useful when you want to inject -configuration or dependencies. However, you must be very careful that they do not cause -eager initialization of too many other beans, because they have to be installed in the -container very early in the application lifecycle. (For example, it is not a good idea to -have them depend on your `DataSource` or JPA configuration.) You can work around such -restrictions by initializing the beans lazily when first used instead of on -initialization. +To add a `Servlet`, `Filter`, or Servlet `*Listener` by using a Spring bean, you must provide a `@Bean` definition for it. +Doing so can be very useful when you want to inject configuration or dependencies. +However, you must be very careful that they do not cause eager initialization of too many other beans, because they have to be installed in the container very early in the application lifecycle. +(For example, it is not a good idea to have them depend on your `DataSource` or JPA configuration.) +You can work around such restrictions by initializing the beans lazily when first used instead of on initialization. -In the case of `Filters` and `Servlets`, you can also add mappings and init parameters by -adding a `FilterRegistrationBean` or a `ServletRegistrationBean` instead of or in -addition to the underlying component. +In the case of `Filters` and `Servlets`, you can also add mappings and init parameters by adding a `FilterRegistrationBean` or a `ServletRegistrationBean` instead of or in addition to the underlying component. [NOTE] ==== -If no `dispatcherType` is specified on a filter registration, `REQUEST` is used. This -aligns with the Servlet Specification's default dispatcher type. +If no `dispatcherType` is specified on a filter registration, `REQUEST` is used. +This aligns with the Servlet Specification's default dispatcher type. ==== -Like any other Spring bean, you can define the order of Servlet filter beans; please -make sure to check the -"`<>`" -section. +Like any other Spring bean, you can define the order of Servlet filter beans; please make sure to check the "`<>`" section. [[howto-disable-registration-of-a-servlet-or-filter]] ===== Disable Registration of a Servlet or Filter -As <>, any -`Servlet` or `Filter` beans are registered with the servlet container automatically. To -disable registration of a particular `Filter` or `Servlet` bean, create a registration -bean for it and mark it as disabled, as shown in the following example: +As <>, any `Servlet` or `Filter` beans are registered with the servlet container automatically. +To disable registration of a particular `Filter` or `Servlet` bean, create a registration bean for it and mark it as disabled, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -902,21 +745,16 @@ bean for it and mark it as disabled, as shown in the following example: [[howto-add-a-servlet-filter-or-listener-using-scanning]] ==== Add Servlets, Filters, and Listeners by Using Classpath Scanning -`@WebServlet`, `@WebFilter`, and `@WebListener` annotated classes can be automatically -registered with an embedded servlet container by annotating a `@Configuration` class -with `@ServletComponentScan` and specifying the package(s) containing the components -that you want to register. By default, `@ServletComponentScan` scans from the package -of the annotated class. +`@WebServlet`, `@WebFilter`, and `@WebListener` annotated classes can be automatically registered with an embedded servlet container by annotating a `@Configuration` class with `@ServletComponentScan` and specifying the package(s) containing the components that you want to register. +By default, `@ServletComponentScan` scans from the package of the annotated class. [[howto-configure-accesslogs]] === Configure Access Logging -Access logs can be configured for Tomcat, Undertow, and Jetty through their respective -namespaces. +Access logs can be configured for Tomcat, Undertow, and Jetty through their respective namespaces. -For instance, the following settings log access on Tomcat with a -{tomcat-documentation}/config/valve.html#Access_Logging[custom pattern]. +For instance, the following settings log access on Tomcat with a {tomcat-documentation}/config/valve.html#Access_Logging[custom pattern]. [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -925,14 +763,11 @@ For instance, the following settings log access on Tomcat with a server.tomcat.accesslog.pattern=%t %a "%r" %s (%D ms) ---- -NOTE: The default location for logs is a `logs` directory relative to the Tomcat base -directory. By default, the `logs` directory is a temporary directory, so you may want to -fix Tomcat's base directory or use an absolute path for the logs. In the preceding -example, the logs are available in `my-tomcat/logs` relative to the working directory of -the application. +NOTE: The default location for logs is a `logs` directory relative to the Tomcat base directory. +By default, the `logs` directory is a temporary directory, so you may want to fix Tomcat's base directory or use an absolute path for the logs. +In the preceding example, the logs are available in `my-tomcat/logs` relative to the working directory of the application. -Access logging for Undertow can be configured in a similar fashion, as shown in the -following example: +Access logging for Undertow can be configured in a similar fashion, as shown in the following example: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -940,9 +775,8 @@ following example: server.undertow.accesslog.pattern=%t %a "%r" %s (%D ms) ---- -Logs are stored in a `logs` directory relative to the working directory of the -application. You can customize this location by setting the -`server.undertow.accesslog.dir` property. +Logs are stored in a `logs` directory relative to the working directory of the application. +You can customize this location by setting the `server.undertow.accesslog.dir` property. Finally, access logging for Jetty can also be configured as follows: @@ -952,34 +786,28 @@ Finally, access logging for Jetty can also be configured as follows: server.jetty.accesslog.filename=/var/log/jetty-access.log ---- -By default, logs are redirected to `System.err`. For more details, see -{jetty-documentation}/configuring-jetty-request-logs.html[the Jetty documentation]. +By default, logs are redirected to `System.err`. +For more details, see {jetty-documentation}/configuring-jetty-request-logs.html[the Jetty documentation]. [[howto-use-behind-a-proxy-server]] [[howto-use-tomcat-behind-a-proxy-server]] === Running Behind a Front-end Proxy Server -Your application might need to send `302` redirects or render content with absolute links -back to itself. When running behind a proxy, the caller wants a link to the proxy and not -to the physical address of the machine hosting your app. Typically, such situations are -handled through a contract with the proxy, which adds headers to tell the back end how to -construct links to itself. +Your application might need to send `302` redirects or render content with absolute links back to itself. +When running behind a proxy, the caller wants a link to the proxy and not to the physical address of the machine hosting your app. +Typically, such situations are handled through a contract with the proxy, which adds headers to tell the back end how to construct links to itself. -If the proxy adds conventional `X-Forwarded-For` and `X-Forwarded-Proto` headers (most -proxy servers do so), the absolute links should be rendered correctly, provided -`server.use-forward-headers` is set to `true` in your `application.properties`. +If the proxy adds conventional `X-Forwarded-For` and `X-Forwarded-Proto` headers (most proxy servers do so), the absolute links should be rendered correctly, provided `server.use-forward-headers` is set to `true` in your `application.properties`. -NOTE: If your application runs in Cloud Foundry or Heroku, the -`server.use-forward-headers` property defaults to `true`. In all -other instances, it defaults to `false`. +NOTE: If your application runs in Cloud Foundry or Heroku, the `server.use-forward-headers` property defaults to `true`. +In all other instances, it defaults to `false`. [[howto-customize-tomcat-behind-a-proxy-server]] ==== Customize Tomcat's Proxy Configuration -If you use Tomcat, you can additionally configure the names of the headers used to -carry "`forwarded`" information, as shown in the following example: +If you use Tomcat, you can additionally configure the names of the headers used to carry "`forwarded`" information, as shown in the following example: [indent=0] ---- @@ -987,34 +815,27 @@ carry "`forwarded`" information, as shown in the following example: server.tomcat.protocol-header=x-your-protocol-header ---- -Tomcat is also configured with a default regular expression that matches internal -proxies that are to be trusted. By default, IP addresses in `10/8`, `192.168/16`, -`169.254/16` and `127/8` are trusted. You can customize the valve's configuration by -adding an entry to `application.properties`, as shown in the following example: +Tomcat is also configured with a default regular expression that matches internal proxies that are to be trusted. +By default, IP addresses in `10/8`, `192.168/16`, `169.254/16` and `127/8` are trusted. +You can customize the valve's configuration by adding an entry to `application.properties`, as shown in the following example: [indent=0] ---- server.tomcat.internal-proxies=192\\.168\\.\\d{1,3}\\.\\d{1,3} ---- -NOTE: The double backslashes are required only when you use a properties file for -configuration. If you use YAML, single backslashes are sufficient, and a value -equivalent to that shown in the preceding example would be `192\.168\.\d{1,3}\.\d{1,3}`. +NOTE: The double backslashes are required only when you use a properties file for configuration. +If you use YAML, single backslashes are sufficient, and a value equivalent to that shown in the preceding example would be `192\.168\.\d{1,3}\.\d{1,3}`. -NOTE: You can trust all proxies by setting the `internal-proxies` to empty (but do not do -so in production). +NOTE: You can trust all proxies by setting the `internal-proxies` to empty (but do not do so in production). -You can take complete control of the configuration of Tomcat's `RemoteIpValve` by -switching the automatic one off (to do so, set `server.use-forward-headers=false`) and -adding a new valve instance in a `TomcatServletWebServerFactory` bean. +You can take complete control of the configuration of Tomcat's `RemoteIpValve` by switching the automatic one off (to do so, set `server.use-forward-headers=false`) and adding a new valve instance in a `TomcatServletWebServerFactory` bean. [[howto-enable-multiple-connectors-in-tomcat]] === Enable Multiple Connectors with Tomcat -You can add an `org.apache.catalina.connector.Connector` to the -`TomcatServletWebServerFactory`, which can allow multiple connectors, including HTTP and -HTTPS connectors, as shown in the following example: +You can add an `org.apache.catalina.connector.Connector` to the `TomcatServletWebServerFactory`, which can allow multiple connectors, including HTTP and HTTPS connectors, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1053,20 +874,16 @@ HTTPS connectors, as shown in the following example: [[howto-use-tomcat-legacycookieprocessor]] === Use Tomcat's LegacyCookieProcessor -By default, the embedded Tomcat used by Spring Boot does not support "Version 0" of the -Cookie format, so you may see the following error: +By default, the embedded Tomcat used by Spring Boot does not support "Version 0" of the Cookie format, so you may see the following error: [indent=0] ---- java.lang.IllegalArgumentException: An invalid character [32] was present in the Cookie value ---- -If at all possible, you should consider updating your code to only store values -compliant with later Cookie specifications. If, however, you cannot change the -way that cookies are written, you can instead configure Tomcat to use a -`LegacyCookieProcessor`. To switch to the `LegacyCookieProcessor`, use an -`WebServerFactoryCustomizer` bean that adds a `TomcatContextCustomizer`, as shown -in the following example: +If at all possible, you should consider updating your code to only store values compliant with later Cookie specifications. +If, however, you cannot change the way that cookies are written, you can instead configure Tomcat to use a `LegacyCookieProcessor`. +To switch to the `LegacyCookieProcessor`, use an `WebServerFactoryCustomizer` bean that adds a `TomcatContextCustomizer`, as shown in the following example: [source,java,indent=0] ---- @@ -1077,8 +894,7 @@ include::{code-examples}/context/embedded/TomcatLegacyCookieProcessorExample.jav [[howto-enable-multiple-listeners-in-undertow]] === Enable Multiple Listeners with Undertow -Add an `UndertowBuilderCustomizer` to the `UndertowServletWebServerFactory` and -add a listener to the `Builder`, as shown in the following example: +Add an `UndertowBuilderCustomizer` to the `UndertowServletWebServerFactory` and add a listener to the `Builder`, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1101,9 +917,7 @@ add a listener to the `Builder`, as shown in the following example: [[howto-create-websocket-endpoints-using-serverendpoint]] === Create WebSocket Endpoints Using @ServerEndpoint -If you want to use `@ServerEndpoint` in a Spring Boot application that used an embedded -container, you must declare a single `ServerEndpointExporter` `@Bean`, as shown in the -following example: +If you want to use `@ServerEndpoint` in a Spring Boot application that used an embedded container, you must declare a single `ServerEndpointExporter` `@Bean`, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1113,24 +927,22 @@ following example: } ---- -The bean shown in the preceding example registers any `@ServerEndpoint` annotated beans -with the underlying WebSocket container. When deployed to a standalone servlet container, -this role is performed by a servlet container initializer, and the -`ServerEndpointExporter` bean is not required. +The bean shown in the preceding example registers any `@ServerEndpoint` annotated beans with the underlying WebSocket container. +When deployed to a standalone servlet container, this role is performed by a servlet container initializer, and the `ServerEndpointExporter` bean is not required. [[howto-spring-mvc]] == Spring MVC +Spring Boot has a number of starters that include Spring MVC. +Note that some starters include a dependency on Spring MVC rather than include it directly. +This section answers common questions about Spring MVC and Spring Boot. + -Spring Boot has a number of starters that include Spring MVC. Note that some starters -include a dependency on Spring MVC rather than include it directly. This section answers -common questions about Spring MVC and Spring Boot. [[howto-write-a-json-rest-service]] === Write a JSON REST Service -Any Spring `@RestController` in a Spring Boot application should render JSON response by -default as long as Jackson2 is on the classpath, as shown in the following example: +Any Spring `@RestController` in a Spring Boot application should render JSON response by default as long as Jackson2 is on the classpath, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1145,18 +957,16 @@ default as long as Jackson2 is on the classpath, as shown in the following examp } ---- -As long as `MyThing` can be serialized by Jackson2 (true for a normal POJO or Groovy -object), then `http://localhost:8080/thing` serves a JSON representation of it by -default. Note that, in a browser, you might sometimes see XML responses, because browsers -tend to send accept headers that prefer XML. +As long as `MyThing` can be serialized by Jackson2 (true for a normal POJO or Groovy object), then `http://localhost:8080/thing` serves a JSON representation of it by default. +Note that, in a browser, you might sometimes see XML responses, because browsers tend to send accept headers that prefer XML. [[howto-write-an-xml-rest-service]] === Write an XML REST Service -If you have the Jackson XML extension (`jackson-dataformat-xml`) on the classpath, you -can use it to render XML responses. The previous example that we used for JSON would -work. To use the Jackson XML renderer, add the following dependency to your project: +If you have the Jackson XML extension (`jackson-dataformat-xml`) on the classpath, you can use it to render XML responses. +The previous example that we used for JSON would work. +To use the Jackson XML renderer, add the following dependency to your project: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1166,9 +976,7 @@ work. To use the Jackson XML renderer, add the following dependency to your proj ---- -If Jackson's XML extension is not available and JAXB is available, XML can be rendered -with the additional requirement of having `MyThing` annotated as `@XmlRootElement`, as -shown in the following example: +If Jackson's XML extension is not available and JAXB is available, XML can be rendered with the additional requirement of having `MyThing` annotated as `@XmlRootElement`, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1179,8 +987,8 @@ shown in the following example: } ---- -JAXB is only available out of the box with Java 8. If you're using a more recent Java -generation, add the following dependency to your project: +JAXB is only available out of the box with Java 8. +If you're using a more recent Java generation, add the following dependency to your project: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1190,20 +998,16 @@ generation, add the following dependency to your project: ---- -NOTE: To get the server to render XML instead of JSON, you might have to send an -`Accept: text/xml` header (or use a browser). +NOTE: To get the server to render XML instead of JSON, you might have to send an `Accept: text/xml` header (or use a browser). [[howto-customize-the-jackson-objectmapper]] === Customize the Jackson ObjectMapper -Spring MVC (client and server side) uses `HttpMessageConverters` to negotiate content -conversion in an HTTP exchange. If Jackson is on the classpath, you already get the -default converter(s) provided by `Jackson2ObjectMapperBuilder`, an instance of which -is auto-configured for you. +Spring MVC (client and server side) uses `HttpMessageConverters` to negotiate content conversion in an HTTP exchange. +If Jackson is on the classpath, you already get the default converter(s) provided by `Jackson2ObjectMapperBuilder`, an instance of which is auto-configured for you. -The `ObjectMapper` (or `XmlMapper` for Jackson XML converter) instance (created by -default) has the following customized properties: +The `ObjectMapper` (or `XmlMapper` for Jackson XML converter) instance (created by default) has the following customized properties: * `MapperFeature.DEFAULT_VIEW_INCLUSION` is disabled * `DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES` is disabled @@ -1212,206 +1016,149 @@ default) has the following customized properties: Spring Boot also has some features to make it easier to customize this behavior. You can configure the `ObjectMapper` and `XmlMapper` instances by using the environment. -Jackson provides an extensive suite of simple on/off features that can be used to -configure various aspects of its processing. These features are described in six enums (in -Jackson) that map onto properties in the environment: +Jackson provides an extensive suite of simple on/off features that can be used to configure various aspects of its processing. +These features are described in six enums (in Jackson) that map onto properties in the environment: |=== -|Enum|Property|Values +| Enum | Property | Values -|`com.fasterxml.jackson.databind.DeserializationFeature` -|`spring.jackson.deserialization.` -|`true`, `false` +| `com.fasterxml.jackson.databind.DeserializationFeature` +| `spring.jackson.deserialization.` +| `true`, `false` -|`com.fasterxml.jackson.core.JsonGenerator.Feature` -|`spring.jackson.generator.` -|`true`, `false` +| `com.fasterxml.jackson.core.JsonGenerator.Feature` +| `spring.jackson.generator.` +| `true`, `false` -|`com.fasterxml.jackson.databind.MapperFeature` -|`spring.jackson.mapper.` -|`true`, `false` +| `com.fasterxml.jackson.databind.MapperFeature` +| `spring.jackson.mapper.` +| `true`, `false` -|`com.fasterxml.jackson.core.JsonParser.Feature` -|`spring.jackson.parser.` -|`true`, `false` +| `com.fasterxml.jackson.core.JsonParser.Feature` +| `spring.jackson.parser.` +| `true`, `false` -|`com.fasterxml.jackson.databind.SerializationFeature` -|`spring.jackson.serialization.` -|`true`, `false` +| `com.fasterxml.jackson.databind.SerializationFeature` +| `spring.jackson.serialization.` +| `true`, `false` -|`com.fasterxml.jackson.annotation.JsonInclude.Include` -|`spring.jackson.default-property-inclusion` -|`always`, `non_null`, `non_absent`, `non_default`, `non_empty` +| `com.fasterxml.jackson.annotation.JsonInclude.Include` +| `spring.jackson.default-property-inclusion` +| `always`, `non_null`, `non_absent`, `non_default`, `non_empty` |=== For example, to enable pretty print, set `spring.jackson.serialization.indent_output=true`. -Note that, thanks to the use of <>, the case of `indent_output` does not have to match the case of the -corresponding enum constant, which is `INDENT_OUTPUT`. +Note that, thanks to the use of <>, the case of `indent_output` does not have to match the case of the corresponding enum constant, which is `INDENT_OUTPUT`. -This environment-based configuration is applied to the auto-configured -`Jackson2ObjectMapperBuilder` bean and applies to any mappers created by -using the builder, including the auto-configured `ObjectMapper` bean. +This environment-based configuration is applied to the auto-configured `Jackson2ObjectMapperBuilder` bean and applies to any mappers created by using the builder, including the auto-configured `ObjectMapper` bean. -The context's `Jackson2ObjectMapperBuilder` can be customized by one or more -`Jackson2ObjectMapperBuilderCustomizer` beans. Such customizer beans can be ordered -(Boot's own customizer has an order of 0), letting additional customization be applied -both before and after Boot's customization. +The context's `Jackson2ObjectMapperBuilder` can be customized by one or more `Jackson2ObjectMapperBuilderCustomizer` beans. +Such customizer beans can be ordered (Boot's own customizer has an order of 0), letting additional customization be applied both before and after Boot's customization. -Any beans of type `com.fasterxml.jackson.databind.Module` are automatically registered -with the auto-configured `Jackson2ObjectMapperBuilder` and are applied to any `ObjectMapper` -instances that it creates. This provides a global mechanism for contributing custom -modules when you add new features to your application. +Any beans of type `com.fasterxml.jackson.databind.Module` are automatically registered with the auto-configured `Jackson2ObjectMapperBuilder` and are applied to any `ObjectMapper` instances that it creates. +This provides a global mechanism for contributing custom modules when you add new features to your application. -If you want to replace the default `ObjectMapper` completely, either define a `@Bean` of -that type and mark it as `@Primary` or, if you prefer the builder-based -approach, define a `Jackson2ObjectMapperBuilder` `@Bean`. Note that, in either case, -doing so disables all auto-configuration of the `ObjectMapper`. +If you want to replace the default `ObjectMapper` completely, either define a `@Bean` of that type and mark it as `@Primary` or, if you prefer the builder-based approach, define a `Jackson2ObjectMapperBuilder` `@Bean`. +Note that, in either case, doing so disables all auto-configuration of the `ObjectMapper`. -If you provide any `@Beans` of type `MappingJackson2HttpMessageConverter`, -they replace the default value in the MVC configuration. Also, a convenience bean of type -`HttpMessageConverters` is provided (and is always available if you use the default MVC -configuration). It has some useful methods to access the default and user-enhanced -message converters. +If you provide any `@Beans` of type `MappingJackson2HttpMessageConverter`, they replace the default value in the MVC configuration. +Also, a convenience bean of type `HttpMessageConverters` is provided (and is always available if you use the default MVC configuration). +It has some useful methods to access the default and user-enhanced message converters. -See the "`<>`" section and the -{sc-spring-boot-autoconfigure}/web/servlet/WebMvcAutoConfiguration.{sc-ext}[`WebMvcAutoConfiguration`] -source code for more details. +See the "`<>`" section and the {sc-spring-boot-autoconfigure}/web/servlet/WebMvcAutoConfiguration.{sc-ext}[`WebMvcAutoConfiguration`] source code for more details. [[howto-customize-the-responsebody-rendering]] === Customize the @ResponseBody Rendering -Spring uses `HttpMessageConverters` to render `@ResponseBody` (or responses from -`@RestController`). You can contribute additional converters by adding beans of the -appropriate type in a Spring Boot context. If a bean you add is of a type that would have -been included by default anyway (such as `MappingJackson2HttpMessageConverter` for JSON -conversions), it replaces the default value. A convenience bean of type -`HttpMessageConverters` is provided and is always available if you use the default MVC -configuration. It has some useful methods to access the default and user-enhanced message -converters (For example, it can be useful if you want to manually inject them into a -custom `RestTemplate`). +Spring uses `HttpMessageConverters` to render `@ResponseBody` (or responses from `@RestController`). +You can contribute additional converters by adding beans of the appropriate type in a Spring Boot context. +If a bean you add is of a type that would have been included by default anyway (such as `MappingJackson2HttpMessageConverter` for JSON conversions), it replaces the default value. +A convenience bean of type `HttpMessageConverters` is provided and is always available if you use the default MVC configuration. +It has some useful methods to access the default and user-enhanced message converters (For example, it can be useful if you want to manually inject them into a custom `RestTemplate`). -As in normal MVC usage, any `WebMvcConfigurer` beans that you provide can also -contribute converters by overriding the `configureMessageConverters` method. However, unlike -with normal MVC, you can supply only additional converters that you need (because Spring -Boot uses the same mechanism to contribute its defaults). Finally, if you opt out of the -Spring Boot default MVC configuration by providing your own `@EnableWebMvc` configuration, -you can take control completely and do everything manually by using -`getMessageConverters` from `WebMvcConfigurationSupport`. +As in normal MVC usage, any `WebMvcConfigurer` beans that you provide can also contribute converters by overriding the `configureMessageConverters` method. +However, unlike with normal MVC, you can supply only additional converters that you need (because Spring Boot uses the same mechanism to contribute its defaults). +Finally, if you opt out of the Spring Boot default MVC configuration by providing your own `@EnableWebMvc` configuration, you can take control completely and do everything manually by using `getMessageConverters` from `WebMvcConfigurationSupport`. -See the -{sc-spring-boot-autoconfigure}/web/servlet/WebMvcAutoConfiguration.{sc-ext}[`WebMvcAutoConfiguration`] -source code for more details. +See the {sc-spring-boot-autoconfigure}/web/servlet/WebMvcAutoConfiguration.{sc-ext}[`WebMvcAutoConfiguration`] source code for more details. [[howto-multipart-file-upload-configuration]] === Handling Multipart File Uploads -Spring Boot embraces the Servlet 3 `javax.servlet.http.Part` API to support uploading -files. By default, Spring Boot configures Spring MVC with a maximum size of 1MB per -file and a maximum of 10MB of file data in a single request. You may override these -values, the location to which intermediate data is stored (for example, to the `/tmp` -directory), and the threshold past which data is flushed to disk by using the properties -exposed in the `MultipartProperties` class. For example, if you want to specify that -files be unlimited, set the `spring.servlet.multipart.max-file-size` property to `-1`. +Spring Boot embraces the Servlet 3 `javax.servlet.http.Part` API to support uploading files. +By default, Spring Boot configures Spring MVC with a maximum size of 1MB per file and a maximum of 10MB of file data in a single request. +You may override these values, the location to which intermediate data is stored (for example, to the `/tmp` directory), and the threshold past which data is flushed to disk by using the properties exposed in the `MultipartProperties` class. +For example, if you want to specify that files be unlimited, set the `spring.servlet.multipart.max-file-size` property to `-1`. -The multipart support is helpful when you want to receive multipart encoded file data as -a `@RequestParam`-annotated parameter of type `MultipartFile` in a Spring MVC controller -handler method. +The multipart support is helpful when you want to receive multipart encoded file data as a `@RequestParam`-annotated parameter of type `MultipartFile` in a Spring MVC controller handler method. -See the -{sc-spring-boot-autoconfigure}/web/servlet/MultipartAutoConfiguration.{sc-ext}[`MultipartAutoConfiguration`] -source for more details. +See the {sc-spring-boot-autoconfigure}/web/servlet/MultipartAutoConfiguration.{sc-ext}[`MultipartAutoConfiguration`] source for more details. -NOTE: It is recommended to use the container's built-in support for multipart uploads -rather than introducing an additional dependency such as Apache Commons File Upload. +NOTE: It is recommended to use the container's built-in support for multipart uploads rather than introducing an additional dependency such as Apache Commons File Upload. [[howto-switch-off-the-spring-mvc-dispatcherservlet]] === Switch Off the Spring MVC DispatcherServlet -By default, all content is served from the root of your application (`/`). If you -would rather map to a different path, you can configure one as follows: +By default, all content is served from the root of your application (`/`). +If you would rather map to a different path, you can configure one as follows: [source,properties,indent=0,subs="verbatim"] ---- spring.mvc.servlet.path=/acme ---- -If you have additional servlets you can declare a `@Bean` of type `Servlet` or -`ServletRegistrationBean` for each and Spring Boot will register them transparently to the -container. Because servlets are registered that way, they can be mapped to a sub-context -of the `DispatcherServlet` without invoking it. +If you have additional servlets you can declare a `@Bean` of type `Servlet` or `ServletRegistrationBean` for each and Spring Boot will register them transparently to the container. +Because servlets are registered that way, they can be mapped to a sub-context of the `DispatcherServlet` without invoking it. -Configuring the `DispatcherServlet` yourself is unusual but if you really need to do it, a -`@Bean` of type `DispatcherServletPath` must be provided as well to provide the path of -your custom `DispatcherServlet`. +Configuring the `DispatcherServlet` yourself is unusual but if you really need to do it, a `@Bean` of type `DispatcherServletPath` must be provided as well to provide the path of your custom `DispatcherServlet`. [[howto-switch-off-default-mvc-configuration]] === Switch off the Default MVC Configuration -The easiest way to take complete control over MVC configuration is to provide your own -`@Configuration` with the `@EnableWebMvc` annotation. Doing so leaves all MVC -configuration in your hands. +The easiest way to take complete control over MVC configuration is to provide your own `@Configuration` with the `@EnableWebMvc` annotation. +Doing so leaves all MVC configuration in your hands. [[howto-customize-view-resolvers]] === Customize ViewResolvers -A `ViewResolver` is a core component of Spring MVC, translating view names in -`@Controller` to actual `View` implementations. Note that `ViewResolvers` are mainly -used in UI applications, rather than REST-style services (a `View` is not used to render -a `@ResponseBody`). There are many implementations of `ViewResolver` to choose from, and -Spring on its own is not opinionated about which ones you should use. Spring Boot, on the -other hand, installs one or two for you, depending on what it finds on the classpath and -in the application context. The `DispatcherServlet` uses all the resolvers it finds in -the application context, trying each one in turn until it gets a result, so, if you -add your own, you have to be aware of the order and in which position your resolver is -added. +A `ViewResolver` is a core component of Spring MVC, translating view names in `@Controller` to actual `View` implementations. +Note that `ViewResolvers` are mainly used in UI applications, rather than REST-style services (a `View` is not used to render a `@ResponseBody`). +There are many implementations of `ViewResolver` to choose from, and Spring on its own is not opinionated about which ones you should use. +Spring Boot, on the other hand, installs one or two for you, depending on what it finds on the classpath and in the application context. +The `DispatcherServlet` uses all the resolvers it finds in the application context, trying each one in turn until it gets a result. +If you add your own, you have to be aware of the order and in which position your resolver is added. `WebMvcAutoConfiguration` adds the following `ViewResolvers` to your context: -* An `InternalResourceViewResolver` named '`defaultViewResolver`'. This one locates -physical resources that can be rendered by using the `DefaultServlet` (including static -resources and JSP pages, if you use those). It applies a prefix and a suffix to the -view name and then looks for a physical resource with that path in the servlet context -(the defaults are both empty but are accessible for external configuration through -`spring.mvc.view.prefix` and `spring.mvc.view.suffix`). You can override it by -providing a bean of the same type. -* A `BeanNameViewResolver` named '`beanNameViewResolver`'. This is a useful member of the -view resolver chain and picks up any beans with the same name as the `View` being -resolved. It should not be necessary to override or replace it. -* A `ContentNegotiatingViewResolver` named '`viewResolver`' is added only if there *are* -actually beans of type `View` present. This is a '`master`' resolver, delegating to all -the others and attempting to find a match to the '`Accept`' HTTP header sent by the -client. There is a useful -https://spring.io/blog/2013/06/03/content-negotiation-using-views[blog about -`ContentNegotiatingViewResolver`] that you might like to study to learn more, and you -might also look at the source code for detail. You can switch off the auto-configured -`ContentNegotiatingViewResolver` by defining a bean named '`viewResolver`'. -* If you use Thymeleaf, you also have a `ThymeleafViewResolver` named -'`thymeleafViewResolver`'. It looks for resources by surrounding the view name with a -prefix and suffix. The prefix is `spring.thymeleaf.prefix`, and the suffix is -`spring.thymeleaf.suffix`. The values of the prefix and suffix default to -'`classpath:/templates/`' and '`.html`', respectively. You can override -`ThymeleafViewResolver` by providing a bean of the same name. -* If you use FreeMarker, you also have a `FreeMarkerViewResolver` named -'`freeMarkerViewResolver`'. It looks for resources in a loader path (which is -externalized to `spring.freemarker.templateLoaderPath` and has a default value of -'`classpath:/templates/`') by surrounding the view name with a prefix and a suffix. The -prefix is externalized to `spring.freemarker.prefix`, and the suffix is externalized to -`spring.freemarker.suffix`. The default values of the prefix and suffix are empty and -'`.ftl`', respectively. You can override `FreeMarkerViewResolver` by providing a bean -of the same name. -* If you use Groovy templates (actually, if `groovy-templates` is on your classpath), you -also have a `GroovyMarkupViewResolver` named '`groovyMarkupViewResolver`'. It looks for -resources in a loader path by surrounding the view name with a prefix and suffix -(externalized to `spring.groovy.template.prefix` and `spring.groovy.template.suffix`). -The prefix and suffix have default values of '`classpath:/templates/`' and '`.tpl`', -respectively. You can override `GroovyMarkupViewResolver` by providing a bean of the -same name. +* An `InternalResourceViewResolver` named '`defaultViewResolver`'. + This one locates physical resources that can be rendered by using the `DefaultServlet` (including static resources and JSP pages, if you use those). + It applies a prefix and a suffix to the view name and then looks for a physical resource with that path in the servlet context (the defaults are both empty but are accessible for external configuration through `spring.mvc.view.prefix` and `spring.mvc.view.suffix`). + You can override it by providing a bean of the same type. +* A `BeanNameViewResolver` named '`beanNameViewResolver`'. + This is a useful member of the view resolver chain and picks up any beans with the same name as the `View` being resolved. + It should not be necessary to override or replace it. +* A `ContentNegotiatingViewResolver` named '`viewResolver`' is added only if there *are* actually beans of type `View` present. + This is a '`master`' resolver, delegating to all the others and attempting to find a match to the '`Accept`' HTTP header sent by the client. + There is a useful https://spring.io/blog/2013/06/03/content-negotiation-using-views[blog about `ContentNegotiatingViewResolver`] that you might like to study to learn more, and you might also look at the source code for detail. + You can switch off the auto-configured `ContentNegotiatingViewResolver` by defining a bean named '`viewResolver`'. +* If you use Thymeleaf, you also have a `ThymeleafViewResolver` named '`thymeleafViewResolver`'. + It looks for resources by surrounding the view name with a prefix and suffix. The prefix is `spring.thymeleaf.prefix`, and the suffix is `spring.thymeleaf.suffix`. + The values of the prefix and suffix default to '`classpath:/templates/`' and '`.html`', respectively. + You can override `ThymeleafViewResolver` by providing a bean of the same name. +* If you use FreeMarker, you also have a `FreeMarkerViewResolver` named '`freeMarkerViewResolver`'. + It looks for resources in a loader path (which is externalized to `spring.freemarker.templateLoaderPath` and has a default value of '`classpath:/templates/`') by surrounding the view name with a prefix and a suffix. + The prefix is externalized to `spring.freemarker.prefix`, and the suffix is externalized to `spring.freemarker.suffix`. + The default values of the prefix and suffix are empty and '`.ftl`', respectively. + You can override `FreeMarkerViewResolver` by providing a bean of the same name. +* If you use Groovy templates (actually, if `groovy-templates` is on your classpath), you also have a `GroovyMarkupViewResolver` named '`groovyMarkupViewResolver`'. + It looks for resources in a loader path by surrounding the view name with a prefix and suffix (externalized to `spring.groovy.template.prefix` and `spring.groovy.template.suffix`). + The prefix and suffix have default values of '`classpath:/templates/`' and '`.tpl`', respectively. + You can override `GroovyMarkupViewResolver` by providing a bean of the same name. For more detail, see the following sections: @@ -1425,8 +1172,7 @@ For more detail, see the following sections: [[howto-use-test-with-spring-security]] == Testing With Spring Security Spring Security provides support for running tests as a specific user. -For example, the test in the snippet below will run with an authenticated user -that has the `ADMIN` role. +For example, the test in the snippet below will run with an authenticated user that has the `ADMIN` role. [source,java,indent=0] ---- @@ -1439,11 +1185,9 @@ that has the `ADMIN` role. } ---- -Spring Security provides comprehensive integration with Spring MVC Test and -this can also be used when testing controllers using the `@WebMvcTest` slice and `MockMvc`. +Spring Security provides comprehensive integration with Spring MVC Test and this can also be used when testing controllers using the `@WebMvcTest` slice and `MockMvc`. -For additional details on Spring Security's testing support, refer to Spring Security's -https://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#test[reference documentation]). +For additional details on Spring Security's testing support, refer to Spring Security's https://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#test[reference documentation]). @@ -1454,15 +1198,11 @@ https://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#t [[howto-jersey-spring-security]] === Secure Jersey endpoints with Spring Security -Spring Security can be used to secure a Jersey-based web application in much the same -way as it can be used to secure a Spring MVC-based web application. However, if you want -to use Spring Security's method-level security with Jersey, you must configure Jersey to -use `setStatus(int)` rather `sendError(int)`. This prevents Jersey from committing the -response before Spring Security has had an opportunity to report an authentication or -authorization failure to the client. +Spring Security can be used to secure a Jersey-based web application in much the same way as it can be used to secure a Spring MVC-based web application. +However, if you want to use Spring Security's method-level security with Jersey, you must configure Jersey to use `setStatus(int)` rather `sendError(int)`. +This prevents Jersey from committing the response before Spring Security has had an opportunity to report an authentication or authorization failure to the client. -The `jersey.config.server.response.setStatusOverSendError` property must be set to `true` -on the application's `ResourceConfig` bean, as shown in the following example: +The `jersey.config.server.response.setStatusOverSendError` property must be set to `true` on the application's `ResourceConfig` bean, as shown in the following example: [source,java,indent=0] ---- @@ -1473,21 +1213,18 @@ include::{code-examples}/jersey/JerseySetStatusOverSendErrorExample.java[tag=res [[howto-http-clients]] == HTTP Clients +Spring Boot offers a number of starters that work with HTTP clients. +This section answers questions related to using them. + -Spring Boot offers a number of starters that work with HTTP clients. This section answers -questions related to using them. [[howto-http-clients-proxy-configuration]] === Configure RestTemplate to Use a Proxy -As described in <>, -you can use a `RestTemplateCustomizer` with `RestTemplateBuilder` to build a customized -`RestTemplate`. This is the recommended approach for creating a `RestTemplate` configured -to use a proxy. +As described in <>, you can use a `RestTemplateCustomizer` with `RestTemplateBuilder` to build a customized `RestTemplate`. +This is the recommended approach for creating a `RestTemplate` configured to use a proxy. -The exact details of the proxy configuration depend on the underlying client request -factory that is being used. The following example configures -`HttpComponentsClientRequestFactory` with an `HttpClient` that uses a proxy for all hosts -except `192.168.0.5`: +The exact details of the proxy configuration depend on the underlying client request factory that is being used. +The following example configures `HttpComponentsClientRequestFactory` with an `HttpClient` that uses a proxy for all hosts except `192.168.0.5`: [source,java,indent=0] ---- @@ -1498,14 +1235,11 @@ include::{code-examples}/web/client/RestTemplateProxyCustomizationExample.java[t [[howto-logging]] == Logging - -Spring Boot has no mandatory logging dependency, except for the Commons Logging API, which -is typically provided by Spring Framework's `spring-jcl` module. To use -https://logback.qos.ch[Logback], you need to include it and `spring-jcl` on the classpath. -The simplest way to do that is through the starters, which all depend on -`spring-boot-starter-logging`. For a web application, you need only -`spring-boot-starter-web`, since it depends transitively on the logging starter. If you -use Maven, the following dependency adds logging for you: +Spring Boot has no mandatory logging dependency, except for the Commons Logging API, which is typically provided by Spring Framework's `spring-jcl` module. +To use https://logback.qos.ch[Logback], you need to include it and `spring-jcl` on the classpath. +The simplest way to do that is through the starters, which all depend on `spring-boot-starter-logging`. +For a web application, you need only `spring-boot-starter-web`, since it depends transitively on the logging starter. +If you use Maven, the following dependency adds logging for you: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1515,12 +1249,10 @@ use Maven, the following dependency adds logging for you: ---- -Spring Boot has a `LoggingSystem` abstraction that attempts to configure logging based on -the content of the classpath. If Logback is available, it is the first choice. +Spring Boot has a `LoggingSystem` abstraction that attempts to configure logging based on the content of the classpath. +If Logback is available, it is the first choice. -If the only change you need to make to logging is to set the levels of various loggers, -you can do so in `application.properties` by using the "logging.level" prefix, as shown -in the following example: +If the only change you need to make to logging is to set the levels of various loggers, you can do so in `application.properties` by using the "logging.level" prefix, as shown in the following example: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1528,23 +1260,17 @@ in the following example: logging.level.org.hibernate=ERROR ---- -You can also set the location of a file to which to write the log (in addition to the -console) by using "logging.file". +You can also set the location of a file to which to write the log (in addition to the console) by using "logging.file". -To configure the more fine-grained settings of a logging system, you need to use the native -configuration format supported by the `LoggingSystem` in question. By default, Spring Boot -picks up the native configuration from its default location for the system (such as -`classpath:logback.xml` for Logback), but you can set the location of the config file by -using the "logging.config" property. +To configure the more fine-grained settings of a logging system, you need to use the native configuration format supported by the `LoggingSystem` in question. +By default, Spring Boot picks up the native configuration from its default location for the system (such as `classpath:logback.xml` for Logback), but you can set the location of the config file by using the "logging.config" property. [[howto-configure-logback-for-logging]] === Configure Logback for Logging -If you put a `logback.xml` in the root of your classpath, it is picked up from there (or -from `logback-spring.xml`, to take advantage of the templating features provided by -Boot). Spring Boot provides a default base configuration that you can include if you -want to set levels, as shown in the following example: +If you put a `logback.xml` in the root of your classpath, it is picked up from there (or from `logback-spring.xml`, to take advantage of the templating features provided by Boot). +Spring Boot provides a default base configuration that you can include if you want to set levels, as shown in the following example: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1555,30 +1281,24 @@ want to set levels, as shown in the following example: ---- -If you look at `base.xml` in the spring-boot jar, you can see that it uses -some useful System properties that the `LoggingSystem` takes care of creating for you: +If you look at `base.xml` in the spring-boot jar, you can see that it uses some useful System properties that the `LoggingSystem` takes care of creating for you: * `$\{PID}`: The current process ID. * `$\{LOG_FILE}`: Whether `logging.file` was set in Boot's external configuration. -* `$\{LOG_PATH}`: Whether `logging.path` (representing a directory for - log files to live in) was set in Boot's external configuration. -* `$\{LOG_EXCEPTION_CONVERSION_WORD}`: Whether `logging.exception-conversion-word` was set - in Boot's external configuration. +* `$\{LOG_PATH}`: Whether `logging.path` (representing a directory for log files to live in) was set in Boot's external configuration. +* `$\{LOG_EXCEPTION_CONVERSION_WORD}`: Whether `logging.exception-conversion-word` was set in Boot's external configuration. -Spring Boot also provides some nice ANSI color terminal output on a console (but not in -a log file) by using a custom Logback converter. See the default `base.xml` configuration -for details. +Spring Boot also provides some nice ANSI color terminal output on a console (but not in a log file) by using a custom Logback converter. +See the default `base.xml` configuration for details. -If Groovy is on the classpath, you should be able to configure Logback with -`logback.groovy` as well. If present, this setting is given preference. +If Groovy is on the classpath, you should be able to configure Logback with `logback.groovy` as well. +If present, this setting is given preference. [[howto-configure-logback-for-logging-fileonly]] ==== Configure Logback for File-only Output -If you want to disable console logging and write output only to a file, you need a custom -`logback-spring.xml` that imports `file-appender.xml` but not `console-appender.xml`, as -shown in the following example: +If you want to disable console logging and write output only to a file, you need a custom `logback-spring.xml` that imports `file-appender.xml` but not `console-appender.xml`, as shown in the following example: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1593,8 +1313,7 @@ shown in the following example: ---- -You also need to add `logging.file` to your `application.properties`, as shown in the -following example: +You also need to add `logging.file` to your `application.properties`, as shown in the following example: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1605,14 +1324,12 @@ following example: [[howto-configure-log4j-for-logging]] === Configure Log4j for Logging -Spring Boot supports https://logging.apache.org/log4j/2.x[Log4j 2] for logging -configuration if it is on the classpath. If you use the starters for -assembling dependencies, you have to exclude Logback and then include log4j 2 -instead. If you do not use the starters, you need to provide (at least) `spring-jcl` in -addition to Log4j 2. +Spring Boot supports https://logging.apache.org/log4j/2.x[Log4j 2] for logging configuration if it is on the classpath. +If you use the starters for assembling dependencies, you have to exclude Logback and then include log4j 2 instead. +If you do not use the starters, you need to provide (at least) `spring-jcl` in addition to Log4j 2. -The simplest path is probably through the starters, even though it requires some -jiggling with excludes. The following example shows how to set up the starters in Maven: +The simplest path is probably through the starters, even though it requires some jiggling with excludes. +The following example shows how to set up the starters in Maven: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1652,55 +1369,45 @@ And the following example shows one way to set up the starters in Gradle: } ---- -NOTE: The Log4j starters gather together the dependencies for common logging -requirements (such as having Tomcat use `java.util.logging` but configuring the -output using Log4j 2). See the -{github-code}/spring-boot-samples/spring-boot-sample-actuator-log4j2[Actuator Log4j 2] -samples for more detail and to see it in action. +NOTE: The Log4j starters gather together the dependencies for common logging requirements (such as having Tomcat use `java.util.logging` but configuring the output using Log4j 2). +See the {github-code}/spring-boot-samples/spring-boot-sample-actuator-log4j2[Actuator Log4j 2] samples for more detail and to see it in action. -NOTE: To ensure that debug logging performed using `java.util.logging` is routed into -Log4j 2, configure its https://logging.apache.org/log4j/2.0/log4j-jul/index.html[JDK -logging adapter] by setting the `java.util.logging.manager` system property to -`org.apache.logging.log4j.jul.LogManager`. +NOTE: To ensure that debug logging performed using `java.util.logging` is routed into Log4j 2, configure its https://logging.apache.org/log4j/2.0/log4j-jul/index.html[JDK logging adapter] by setting the `java.util.logging.manager` system property to `org.apache.logging.log4j.jul.LogManager`. [[howto-configure-log4j-for-logging-yaml-or-json-config]] ==== Use YAML or JSON to Configure Log4j 2 -In addition to its default XML configuration format, Log4j 2 also supports YAML and JSON -configuration files. To configure Log4j 2 to use an alternative configuration file format, -add the appropriate dependencies to the classpath and name your -configuration files to match your chosen file format, as shown in the following example: +In addition to its default XML configuration format, Log4j 2 also supports YAML and JSON configuration files. +To configure Log4j 2 to use an alternative configuration file format, add the appropriate dependencies to the classpath and name your configuration files to match your chosen file format, as shown in the following example: -[cols="10,75,15"] +[cols="10,75a,15a"] |=== -|Format|Dependencies|File names +| Format | Dependencies | File names |YAML -a| `com.fasterxml.jackson.core:jackson-databind` + - `com.fasterxml.jackson.dataformat:jackson-dataformat-yaml` -a| `log4j2.yaml` + - `log4j2.yml` +| `com.fasterxml.jackson.core:jackson-databind` + `com.fasterxml.jackson.dataformat:jackson-dataformat-yaml` +| `log4j2.yaml` + `log4j2.yml` |JSON -a| `com.fasterxml.jackson.core:jackson-databind` -a| `log4j2.json` + - `log4j2.jsn` +| `com.fasterxml.jackson.core:jackson-databind` +| `log4j2.json` + `log4j2.jsn` |=== + + [[howto-data-access]] == Data Access +Spring Boot includes a number of starters for working with data sources. +This section answers questions related to doing so. + -Spring Boot includes a number of starters for working with data sources. This section -answers questions related to doing so. [[howto-configure-a-datasource]] === Configure a Custom DataSource To configure your own `DataSource`, define a `@Bean` of that type in your configuration. -Spring Boot reuses your `DataSource` anywhere one is required, including database -initialization. If you need to externalize some settings, you can bind your -`DataSource` to the environment (see -"`<>`"). +Spring Boot reuses your `DataSource` anywhere one is required, including database initialization. +If you need to externalize some settings, you can bind your `DataSource` to the environment (see "`<>`"). The following example shows how to define a data source in a bean: @@ -1722,17 +1429,12 @@ The following example shows how to define a data source by setting properties: app.datasource.pool-size=30 ---- -Assuming that your `FancyDataSource` has regular JavaBean properties for the URL, the -username, and the pool size, these settings are bound automatically before the -`DataSource` is made available to other components. The regular -<> also happens -(so the relevant sub-set of `spring.datasource.*` can still be used with your custom -configuration). +Assuming that your `FancyDataSource` has regular JavaBean properties for the URL, the username, and the pool size, these settings are bound automatically before the `DataSource` is made available to other components. +The regular <> also happens (so the relevant sub-set of `spring.datasource.*` can still be used with your custom configuration). -Spring Boot also provides a utility builder class, called `DataSourceBuilder`, that can -be used to create one of the standard data sources (if it is on the classpath). The -builder can detect the one to use based on what's available on the classpath. It also -auto-detects the driver based on the JDBC URL. +Spring Boot also provides a utility builder class, called `DataSourceBuilder`, that can be used to create one of the standard data sources (if it is on the classpath). +The builder can detect the one to use based on what's available on the classpath. +It also auto-detects the driver based on the JDBC URL. The following example shows how to create a data source by using a `DataSourceBuilder`: @@ -1741,9 +1443,9 @@ The following example shows how to create a data source by using a `DataSourceBu include::{code-examples}/jdbc/BasicDataSourceExample.java[tag=configuration] ---- -To run an app with that `DataSource`, all you need is the connection -information. Pool-specific settings can also be provided. Check the implementation that -is going to be used at runtime for more details. +To run an app with that `DataSource`, all you need is the connection information. +Pool-specific settings can also be provided. +Check the implementation that is going to be used at runtime for more details. The following example shows how to define a JDBC data source by setting properties: @@ -1755,12 +1457,9 @@ The following example shows how to define a JDBC data source by setting properti app.datasource.pool-size=30 ---- -However, there is a catch. Because the actual type of the connection pool is not exposed, -no keys are generated in the metadata for your custom `DataSource` and no completion is -available in your IDE (because the `DataSource` interface exposes no properties). Also, if -you happen to have Hikari on the classpath, this basic setup does not work, because Hikari -has no `url` property (but does have a `jdbcUrl` property). In that case, you must rewrite -your configuration as follows: +However, there is a catch. +Because the actual type of the connection pool is not exposed, no keys are generated in the metadata for your custom `DataSource` and no completion is available in your IDE (because the `DataSource` interface exposes no properties). +Also, if you happen to have Hikari on the classpath, this basic setup does not work, because Hikari has no `url` property (but does have a `jdbcUrl` property). In that case, you must rewrite your configuration as follows: [source,properties,indent=0] ---- @@ -1770,9 +1469,8 @@ your configuration as follows: app.datasource.maximum-pool-size=30 ---- -You can fix that by forcing the connection pool to use and return a dedicated -implementation rather than `DataSource`. You cannot change the implementation -at runtime, but the list of options will be explicit. +You can fix that by forcing the connection pool to use and return a dedicated implementation rather than `DataSource`. +You cannot change the implementation at runtime, but the list of options will be explicit. The following example shows how create a `HikariDataSource` with `DataSourceBuilder`: @@ -1781,24 +1479,18 @@ The following example shows how create a `HikariDataSource` with `DataSourceBuil include::{code-examples}/jdbc/SimpleDataSourceExample.java[tag=configuration] ---- -You can even go further by leveraging what `DataSourceProperties` does for you -- that is, -by providing a default embedded database with a sensible username and password if no URL -is provided. You can easily initialize a `DataSourceBuilder` from the state of any -`DataSourceProperties` object, so you could also inject the DataSource that Spring Boot -creates automatically. However, that would split your configuration into two namespaces: -`url`, `username`, `password`, `type`, and `driver` on `spring.datasource` and the rest on -your custom namespace (`app.datasource`). To avoid that, you can redefine a custom -`DataSourceProperties` on your custom namespace, as shown in the following example: +You can even go further by leveraging what `DataSourceProperties` does for you -- that is, by providing a default embedded database with a sensible username and password if no URL is provided. +You can easily initialize a `DataSourceBuilder` from the state of any `DataSourceProperties` object, so you could also inject the DataSource that Spring Boot creates automatically. +However, that would split your configuration into two namespaces: `url`, `username`, `password`, `type`, and `driver` on `spring.datasource` and the rest on your custom namespace (`app.datasource`). +To avoid that, you can redefine a custom `DataSourceProperties` on your custom namespace, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- include::{code-examples}/jdbc/ConfigurableDataSourceExample.java[tag=configuration] ---- -This setup puts you _in sync_ with what Spring Boot does for you by default, except that -a dedicated connection pool is chosen (in code) and its settings are exposed in the -`app.datasource.configuration` sub namespace. Because `DataSourceProperties` is taking -care of the `url`/`jdbcUrl` translation for you, you can configure it as follows: +This setup puts you _in sync_ with what Spring Boot does for you by default, except that a dedicated connection pool is chosen (in code) and its settings are exposed in the `app.datasource.configuration` sub namespace. +Because `DataSourceProperties` is taking care of the `url`/`jdbcUrl` translation for you, you can configure it as follows: [source,properties,indent=0] ---- @@ -1808,42 +1500,31 @@ care of the `url`/`jdbcUrl` translation for you, you can configure it as follows app.datasource.configuration.maximum-pool-size=30 ---- -TIP: Spring Boot will expose Hikari-specific settings to `spring.datasource.hikari`. This -example uses a more generic `configuration` sub namespace as the example does not support -multiple datasource implementations. +TIP: Spring Boot will expose Hikari-specific settings to `spring.datasource.hikari`. +This example uses a more generic `configuration` sub namespace as the example does not support multiple datasource implementations. -NOTE: Because your custom configuration chooses to go with Hikari, `app.datasource.type` -has no effect. In practice, the builder is initialized with whatever value you -might set there and then overridden by the call to `.type()`. +NOTE: Because your custom configuration chooses to go with Hikari, `app.datasource.type` has no effect. +In practice, the builder is initialized with whatever value you might set there and then overridden by the call to `.type()`. -See "`<>`" in the -"`Spring Boot features`" section and the -{sc-spring-boot-autoconfigure}/jdbc/DataSourceAutoConfiguration.{sc-ext}[`DataSourceAutoConfiguration`] -class for more details. +See "`<>`" in the "`Spring Boot features`" section and the {sc-spring-boot-autoconfigure}/jdbc/DataSourceAutoConfiguration.{sc-ext}[`DataSourceAutoConfiguration`] class for more details. [[howto-two-datasources]] === Configure Two DataSources -If you need to configure multiple data sources, you can apply the same tricks that are -described in the previous section. You must, however, mark one of the `DataSource` -instances as `@Primary`, because various auto-configurations down the road expect to be -able to get one by type. +If you need to configure multiple data sources, you can apply the same tricks that are described in the previous section. +You must, however, mark one of the `DataSource` instances as `@Primary`, because various auto-configurations down the road expect to be able to get one by type. -If you create your own `DataSource`, the auto-configuration backs off. In the following -example, we provide the _exact_ same feature set as the auto-configuration provides -on the primary data source: +If you create your own `DataSource`, the auto-configuration backs off. In the following example, we provide the _exact_ same feature set as the auto-configuration provides on the primary data source: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- include::{code-examples}/jdbc/SimpleTwoDataSourcesExample.java[tag=configuration] ---- -TIP: `firstDataSourceProperties` has to be flagged as `@Primary` so that the database -initializer feature uses your copy (if you use the initializer). +TIP: `firstDataSourceProperties` has to be flagged as `@Primary` so that the database initializer feature uses your copy (if you use the initializer). -Both data sources are also bound for advanced customizations. For instance, you could -configure them as follows: +Both data sources are also bound for advanced customizations. For instance, you could configure them as follows: [source,properties,indent=0] ---- @@ -1858,36 +1539,29 @@ configure them as follows: app.datasource.second.max-total=30 ---- -You can apply the same concept to the secondary `DataSource` as well, as shown in the -following example: +You can apply the same concept to the secondary `DataSource` as well, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- include::{code-examples}/jdbc/CompleteTwoDataSourcesExample.java[tag=configuration] ---- -The preceding example configures two data sources on custom namespaces with the same -logic as Spring Boot would use in auto-configuration. Note that each `configuration` sub -namespace provides advanced settings based on the chosen implementation. +The preceding example configures two data sources on custom namespaces with the same logic as Spring Boot would use in auto-configuration. +Note that each `configuration` sub namespace provides advanced settings based on the chosen implementation. [[howto-use-spring-data-repositories]] === Use Spring Data Repositories Spring Data can create implementations of `@Repository` interfaces of various flavors. -Spring Boot handles all of that for you, as long as those `@Repositories` are included in -the same package (or a sub-package) of your `@EnableAutoConfiguration` class. +Spring Boot handles all of that for you, as long as those `@Repositories` are included in the same package (or a sub-package) of your `@EnableAutoConfiguration` class. -For many applications, all you need is to put the right Spring Data dependencies on -your classpath (there is a `spring-boot-starter-data-jpa` for JPA and a -`spring-boot-starter-data-mongodb` for Mongodb) and create some repository interfaces to -handle your `@Entity` objects. Examples are in the -{github-code}/spring-boot-samples/spring-boot-sample-data-jpa[JPA sample] and the -{github-code}/spring-boot-samples/spring-boot-sample-data-mongodb[Mongodb sample]. +For many applications, all you need is to put the right Spring Data dependencies on your classpath and create some repository interfaces to handle your `@Entity` objects. +There is a `spring-boot-starter-data-jpa` for JPA, spring-boot-starter-data-mongodb` for Mongodb, etc. +Examples are in the {github-code}/spring-boot-samples/spring-boot-sample-data-jpa[JPA sample] and the {github-code}/spring-boot-samples/spring-boot-sample-data-mongodb[Mongodb sample]. -Spring Boot tries to guess the location of your `@Repository` definitions, based on the -`@EnableAutoConfiguration` it finds. To get more control, use the `@EnableJpaRepositories` -annotation (from Spring Data JPA). +Spring Boot tries to guess the location of your `@Repository` definitions, based on the `@EnableAutoConfiguration` it finds. +To get more control, use the `@EnableJpaRepositories` annotation (from Spring Data JPA). For more about Spring Data, see the {spring-data}[Spring Data project page]. @@ -1895,9 +1569,8 @@ For more about Spring Data, see the {spring-data}[Spring Data project page]. [[howto-separate-entity-definitions-from-spring-configuration]] === Separate @Entity Definitions from Spring Configuration -Spring Boot tries to guess the location of your `@Entity` definitions, based on the -`@EnableAutoConfiguration` it finds. To get more control, you can use the `@EntityScan` -annotation, as shown in the following example: +Spring Boot tries to guess the location of your `@Entity` definitions, based on the `@EnableAutoConfiguration` it finds. +To get more control, you can use the `@EntityScan` annotation, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1915,25 +1588,18 @@ annotation, as shown in the following example: [[howto-configure-jpa-properties]] === Configure JPA Properties -Spring Data JPA already provides some vendor-independent configuration options (such as -those for SQL logging), and Spring Boot exposes those options and a few more for Hibernate -as external configuration properties. Some of them are automatically detected according to -the context so you should not have to set them. +Spring Data JPA already provides some vendor-independent configuration options (such as those for SQL logging), and Spring Boot exposes those options and a few more for Hibernate as external configuration properties. +Some of them are automatically detected according to the context so you should not have to set them. -The `spring.jpa.hibernate.ddl-auto` is a special case, because, depending on runtime -conditions, it has different defaults. If an embedded database is used and no schema -manager (such as Liquibase or Flyway) is handling the `DataSource`, it defaults to -`create-drop`. In all other cases, it defaults to `none`. +The `spring.jpa.hibernate.ddl-auto` is a special case, because, depending on runtime conditions, it has different defaults. +If an embedded database is used and no schema manager (such as Liquibase or Flyway) is handling the `DataSource`, it defaults to `create-drop`. +In all other cases, it defaults to `none`. -The dialect to use is also automatically detected based on the current `DataSource`, but -you can set `spring.jpa.database` yourself if you want to be explicit and bypass that -check on startup. +The dialect to use is also automatically detected based on the current `DataSource`, but you can set `spring.jpa.database` yourself if you want to be explicit and bypass that check on startup. -NOTE: Specifying a `database` leads to the configuration of a well-defined Hibernate -dialect. Several databases have more than one `Dialect`, and this may not suit your needs. -In that case, you can either set `spring.jpa.database` to `default` to let Hibernate -figure things out or set the dialect by setting the `spring.jpa.database-platform` -property. +NOTE: Specifying a `database` leads to the configuration of a well-defined Hibernate dialect. +Several databases have more than one `Dialect`, and this may not suit your needs. +In that case, you can either set `spring.jpa.database` to `default` to let Hibernate figure things out or set the dialect by setting the `spring.jpa.database-platform` property. The most common options to set are shown in the following example: @@ -1943,32 +1609,22 @@ The most common options to set are shown in the following example: spring.jpa.show-sql=true ---- -In addition, all properties in `+spring.jpa.properties.*+` are passed through as normal -JPA properties (with the prefix stripped) when the local `EntityManagerFactory` is -created. +In addition, all properties in `+spring.jpa.properties.*+` are passed through as normal JPA properties (with the prefix stripped) when the local `EntityManagerFactory` is created. -TIP: If you need to apply advanced customization to Hibernate properties, consider -registering a `HibernatePropertiesCustomizer` bean that will be invoked prior to creating -the `EntityManagerFactory`. This takes precedence to anything that is applied by the -auto-configuration. +TIP: If you need to apply advanced customization to Hibernate properties, consider registering a `HibernatePropertiesCustomizer` bean that will be invoked prior to creating the `EntityManagerFactory`. +This takes precedence to anything that is applied by the auto-configuration. [[howto-configure-hibernate-naming-strategy]] === Configure Hibernate Naming Strategy -Hibernate uses {hibernate-documentation}#naming[two different naming strategies] to map -names from the object model to the corresponding database names. The fully qualified -class name of the physical and the implicit strategy implementations can be configured by -setting the `spring.jpa.hibernate.naming.physical-strategy` and -`spring.jpa.hibernate.naming.implicit-strategy` properties, respectively. Alternatively, -if `ImplicitNamingStrategy` or `PhysicalNamingStrategy` beans are available in the -application context, Hibernate will be automatically configured to use them. +Hibernate uses {hibernate-documentation}#naming[two different naming strategies] to map names from the object model to the corresponding database names. +The fully qualified class name of the physical and the implicit strategy implementations can be configured by setting the `spring.jpa.hibernate.naming.physical-strategy` and `spring.jpa.hibernate.naming.implicit-strategy` properties, respectively. +Alternatively, if `ImplicitNamingStrategy` or `PhysicalNamingStrategy` beans are available in the application context, Hibernate will be automatically configured to use them. -By default, Spring Boot configures the physical naming strategy with -`SpringPhysicalNamingStrategy`. This implementation provides the same table structure as -Hibernate 4: all dots are replaced by underscores and camel casing is replaced by -underscores as well. By default, all table names are generated in lower case, but it is -possible to override that flag if your schema requires it. +By default, Spring Boot configures the physical naming strategy with `SpringPhysicalNamingStrategy`. +This implementation provides the same table structure as Hibernate 4: all dots are replaced by underscores and camel casing is replaced by underscores as well. +By default, all table names are generated in lower case, but it is possible to override that flag if your schema requires it. For example, a `TelephoneNumber` entity is mapped to the `telephone_number` table. @@ -1989,61 +1645,50 @@ Alternatively, you can configure the following bean: } ---- -See {sc-spring-boot-autoconfigure}/orm/jpa/HibernateJpaAutoConfiguration.{sc-ext}[`HibernateJpaAutoConfiguration`] -and {sc-spring-boot-autoconfigure}/orm/jpa/JpaBaseConfiguration.{sc-ext}[`JpaBaseConfiguration`] -for more details. +See {sc-spring-boot-autoconfigure}/orm/jpa/HibernateJpaAutoConfiguration.{sc-ext}[`HibernateJpaAutoConfiguration`] and {sc-spring-boot-autoconfigure}/orm/jpa/JpaBaseConfiguration.{sc-ext}[`JpaBaseConfiguration`] for more details. [[howto-configure-hibernate-second-level-caching]] === Configure Hibernate Second-Level Caching -Hibernate {hibernate-documentation}#caching[second-level cache] can be configured for a -range of cache providers. Rather than configuring Hibernate to lookup the cache provider -again, it is better to provide the one that is available in the context whenever possible. +Hibernate {hibernate-documentation}#caching[second-level cache] can be configured for a range of cache providers. +Rather than configuring Hibernate to lookup the cache provider again, it is better to provide the one that is available in the context whenever possible. -If you're using JCache, this is pretty easy. First, make sure that -`org.hibernate:hibernate-jcache` is available on the classpath. Then, add a -`HibernatePropertiesCustomizer` bean as shown in the following example: +If you're using JCache, this is pretty easy. First, make sure that `org.hibernate:hibernate-jcache` is available on the classpath. +Then, add a `HibernatePropertiesCustomizer` bean as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/jpa/HibernateSecondLevelCacheExample.java[tag=configuration] ---- -This customizer will configure Hibernate to use the same `CacheManager` as the one that -the application uses. It is also possible to use separate `CacheManager` instances. For -details, refer to {hibernate-documentation}#caching-provider-jcache[the Hibernate user -guide]. +This customizer will configure Hibernate to use the same `CacheManager` as the one that the application uses. +It is also possible to use separate `CacheManager` instances. +For details, refer to {hibernate-documentation}#caching-provider-jcache[the Hibernate user guide]. [[howto-use-dependency-injection-hibernate-components]] === Use Dependency Injection in Hibernate Components -By default, Spring Boot registers a `BeanContainer` implementation that uses the -`BeanFactory` so that converters and entity listeners can use regular dependency -injection. +By default, Spring Boot registers a `BeanContainer` implementation that uses the `BeanFactory` so that converters and entity listeners can use regular dependency injection. -You can disable or tune this behaviour by registering a `HibernatePropertiesCustomizer` -that removes or changes the `hibernate.resource.beans.container` property. +You can disable or tune this behaviour by registering a `HibernatePropertiesCustomizer` that removes or changes the `hibernate.resource.beans.container` property. [[howto-use-custom-entity-manager]] === Use a Custom EntityManagerFactory -To take full control of the configuration of the `EntityManagerFactory`, you need to add -a `@Bean` named '`entityManagerFactory`'. Spring Boot auto-configuration switches off its -entity manager in the presence of a bean of that type. +To take full control of the configuration of the `EntityManagerFactory`, you need to add a `@Bean` named '`entityManagerFactory`'. +Spring Boot auto-configuration switches off its entity manager in the presence of a bean of that type. [[howto-use-two-entity-managers]] === Use Two EntityManagers Even if the default `EntityManagerFactory` works fine, you need to define a new one. -Otherwise, the presence of the second bean of that type switches off the -default. To make it easy to do, you can use the convenient `EntityManagerBuilder` -provided by Spring Boot. Alternatively, you can just the -`LocalContainerEntityManagerFactoryBean` directly from Spring ORM, as shown in the -following example: +Otherwise, the presence of the second bean of that type switches off the default. +To make it easy to do, you can use the convenient `EntityManagerBuilder` provided by Spring Boot. +Alternatively, you can just the `LocalContainerEntityManagerFactoryBean` directly from Spring ORM, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2070,14 +1715,13 @@ following example: } ---- -The configuration above almost works on its own. To complete the picture, you need to -configure `TransactionManagers` for the two `EntityManagers` as well. If you mark one of -them as `@Primary`, it could be picked up by the default `JpaTransactionManager` in Spring -Boot. The other would have to be explicitly injected into a new instance. Alternatively, -you might be able to use a JTA transaction manager that spans both. +The configuration above almost works on its own. +To complete the picture, you need to configure `TransactionManagers` for the two `EntityManagers` as well. +If you mark one of them as `@Primary`, it could be picked up by the default `JpaTransactionManager` in Spring Boot. +The other would have to be explicitly injected into a new instance. +Alternatively, you might be able to use a JTA transaction manager that spans both. -If you use Spring Data, you need to configure `@EnableJpaRepositories` accordingly, -as shown in the following example: +If you use Spring Data, you need to configure `@EnableJpaRepositories` accordingly, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2100,45 +1744,32 @@ as shown in the following example: [[howto-use-traditional-persistence-xml]] === Use a Traditional `persistence.xml` File -Spring Boot will not search for or use a `META-INF/persistence.xml` by default. If you -prefer to use a traditional `persistence.xml`, you need to define your own `@Bean` of -type `LocalEntityManagerFactoryBean` (with an ID of '`entityManagerFactory`') and set the -persistence unit name there. +Spring Boot will not search for or use a `META-INF/persistence.xml` by default. +If you prefer to use a traditional `persistence.xml`, you need to define your own `@Bean` of type `LocalEntityManagerFactoryBean` (with an ID of '`entityManagerFactory`') and set the persistence unit name there. -See -{sc-spring-boot-autoconfigure}/orm/jpa/JpaBaseConfiguration.{sc-ext}[`JpaBaseConfiguration`] -for the default settings. +See {sc-spring-boot-autoconfigure}/orm/jpa/JpaBaseConfiguration.{sc-ext}[`JpaBaseConfiguration`] for the default settings. [[howto-use-spring-data-jpa--and-mongo-repositories]] === Use Spring Data JPA and Mongo Repositories +Spring Data JPA and Spring Data Mongo can both automatically create `Repository` implementations for you. +If they are both present on the classpath, you might have to do some extra configuration to tell Spring Boot which repositories to create. +The most explicit way to do that is to use the standard Spring Data `+@EnableJpaRepositories+` and `+@EnableMongoRepositories+` annotations and provide the location of your `Repository` interfaces. -Spring Data JPA and Spring Data Mongo can both automatically create `Repository` -implementations for you. If they are both present on the classpath, you might have to do -some extra configuration to tell Spring Boot which repositories to create. The most -explicit way to do that is to use the standard Spring Data `+@EnableJpaRepositories+` and -`+@EnableMongoRepositories+` annotations and provide the location of your `Repository` -interfaces. +There are also flags (`+spring.data.*.repositories.enabled+` and `+spring.data.*.repositories.type+`) that you can use to switch the auto-configured repositories on and off in external configuration. +Doing so is useful, for instance, in case you want to switch off the Mongo repositories and still use the auto-configured `MongoTemplate`. -There are also flags (`+spring.data.*.repositories.enabled+` and -`+spring.data.*.repositories.type+`) that you can use to switch the auto-configured -repositories on and off in external configuration. Doing so is useful, for instance, in -case you want to switch off the Mongo repositories and still use the auto-configured -`MongoTemplate`. - -The same obstacle and the same features exist for other auto-configured Spring Data -repository types (Elasticsearch, Solr, and others). To work with them, change the names of -the annotations and flags accordingly. +The same obstacle and the same features exist for other auto-configured Spring Data repository types (Elasticsearch, Solr, and others). +To work with them, change the names of the annotations and flags accordingly. [[howto-use-customize-spring-datas-web-support]] === Customize Spring Data's Web Support -Spring Data provides web support that simplifies the use of Spring Data repositories in a -web application. Spring Boot provides properties in the `spring.data.web` namespace -for customizing its configuration. Note that if you are using Spring Data REST, you must -use the properties in the `spring.data.rest` namespace instead. +Spring Data provides web support that simplifies the use of Spring Data repositories in a web application. +Spring Boot provides properties in the `spring.data.web` namespace for customizing its configuration. +Note that if you are using Spring Data REST, you must use the properties in the `spring.data.rest` namespace instead. [[howto-use-exposing-spring-data-repositories-rest-endpoint]] @@ -2146,32 +1777,22 @@ use the properties in the `spring.data.rest` namespace instead. Spring Data REST can expose the `Repository` implementations as REST endpoints for you, provided Spring MVC has been enabled for the application. -Spring Boot exposes a set of useful properties (from the `spring.data.rest` namespace) -that customize the -{spring-data-rest-javadoc}/core/config/RepositoryRestConfiguration.{dc-ext}[`RepositoryRestConfiguration`]. -If you need to provide additional customization, you should use a -{spring-data-rest-javadoc}/webmvc/config/RepositoryRestConfigurer.{dc-ext}[`RepositoryRestConfigurer`] -bean. +Spring Boot exposes a set of useful properties (from the `spring.data.rest` namespace) that customize the {spring-data-rest-javadoc}/core/config/RepositoryRestConfiguration.{dc-ext}[`RepositoryRestConfiguration`]. +If you need to provide additional customization, you should use a {spring-data-rest-javadoc}/webmvc/config/RepositoryRestConfigurer.{dc-ext}[`RepositoryRestConfigurer`] bean. -NOTE: If you do not specify any order on your custom `RepositoryRestConfigurer`, it runs -after the one Spring Boot uses internally. If you need to specify an order, make sure it -is higher than 0. +NOTE: If you do not specify any order on your custom `RepositoryRestConfigurer`, it runs after the one Spring Boot uses internally. +If you need to specify an order, make sure it is higher than 0. [[howto-configure-a-component-that-is-used-by-JPA]] === Configure a Component that is Used by JPA -If you want to configure a component that JPA uses, then you need to ensure -that the component is initialized before JPA. When the component is auto-configured, -Spring Boot takes care of this for you. For example, when Flyway is auto-configured, -Hibernate is configured to depend upon Flyway so that Flyway has a chance to -initialize the database before Hibernate tries to use it. +If you want to configure a component that JPA uses, then you need to ensure that the component is initialized before JPA. +When the component is auto-configured, Spring Boot takes care of this for you. +For example, when Flyway is auto-configured, Hibernate is configured to depend upon Flyway so that Flyway has a chance to initialize the database before Hibernate tries to use it. -If you are configuring a component yourself, you can use an -`EntityManagerFactoryDependsOnPostProcessor` subclass as a convenient way of setting up -the necessary dependencies. For example, if you use Hibernate Search with -Elasticsearch as its index manager, any `EntityManagerFactory` beans must be -configured to depend on the `elasticsearchClient` bean, as shown in the following example: +If you are configuring a component yourself, you can use an `EntityManagerFactoryDependsOnPostProcessor` subclass as a convenient way of setting up the necessary dependencies. +For example, if you use Hibernate Search with Elasticsearch as its index manager, any `EntityManagerFactory` beans must be configured to depend on the `elasticsearchClient` bean, as shown in the following example: [source,java,indent=0] ---- @@ -2182,14 +1803,10 @@ include::{code-examples}/elasticsearch/HibernateSearchElasticsearchExample.java[ [[howto-configure-jOOQ-with-multiple-datasources]] === Configure jOOQ with Two DataSources -If you need to use jOOQ with multiple data sources, you should create your own -`DSLContext` for each one. Refer to -{sc-spring-boot-autoconfigure}/jooq/JooqAutoConfiguration.{sc-ext}[JooqAutoConfiguration] -for more details. +If you need to use jOOQ with multiple data sources, you should create your own `DSLContext` for each one. +Refer to {sc-spring-boot-autoconfigure}/jooq/JooqAutoConfiguration.{sc-ext}[JooqAutoConfiguration] for more details. -TIP: In particular, `JooqExceptionTranslator` and `SpringTransactionProvider` can be -reused to provide similar features to what the auto-configuration does with a single -`DataSource`. +TIP: In particular, `JooqExceptionTranslator` and `SpringTransactionProvider` can be reused to provide similar features to what the auto-configuration does with a single `DataSource`. @@ -2203,55 +1820,46 @@ It is recommended to use a single mechanism for schema generation. [[howto-initialize-a-database-using-jpa]] === Initialize a Database Using JPA -JPA has features for DDL generation, and these can be set up to run on startup against the -database. This is controlled through two external properties: +JPA has features for DDL generation, and these can be set up to run on startup against the database. +This is controlled through two external properties: -* `spring.jpa.generate-ddl` (boolean) switches the feature on and off and is vendor -independent. -* `spring.jpa.hibernate.ddl-auto` (enum) is a Hibernate feature that controls the -behavior in a more fine-grained way. This feature is described in more detail later in -this guide. +* `spring.jpa.generate-ddl` (boolean) switches the feature on and off and is vendor independent. +* `spring.jpa.hibernate.ddl-auto` (enum) is a Hibernate feature that controls the behavior in a more fine-grained way. + This feature is described in more detail later in this guide. [[howto-initialize-a-database-using-hibernate]] === Initialize a Database Using Hibernate -You can set `spring.jpa.hibernate.ddl-auto` explicitly and the standard Hibernate property -values are `none`, `validate`, `update`, `create`, and `create-drop`. Spring Boot chooses -a default value for you based on whether it thinks your database is embedded. It defaults -to `create-drop` if no schema manager has been detected or `none` in all other cases. An -embedded database is detected by looking at the `Connection` type. `hsqldb`, `h2`, and -`derby` are embedded, and others are not. Be careful when switching from in-memory to a -'`real`' database that you do not make assumptions about the existence of the tables and -data in the new platform. You either have to set `ddl-auto` explicitly or use one of the -other mechanisms to initialize the database. +You can set `spring.jpa.hibernate.ddl-auto` explicitly and the standard Hibernate property values are `none`, `validate`, `update`, `create`, and `create-drop`. +Spring Boot chooses a default value for you based on whether it thinks your database is embedded. +It defaults to `create-drop` if no schema manager has been detected or `none` in all other cases. +An embedded database is detected by looking at the `Connection` type. `hsqldb`, `h2`, and `derby` are embedded, and others are not. +Be careful when switching from in-memory to a '`real`' database that you do not make assumptions about the existence of the tables and data in the new platform. +You either have to set `ddl-auto` explicitly or use one of the other mechanisms to initialize the database. -NOTE: You can output the schema creation by enabling the `org.hibernate.SQL` logger. This -is done for you automatically if you enable the -<>. +NOTE: You can output the schema creation by enabling the `org.hibernate.SQL` logger. +This is done for you automatically if you enable the <>. -In addition, a file named `import.sql` in the root of the classpath is executed on -startup if Hibernate creates the schema from scratch (that is, if the `ddl-auto` property -is set to `create` or `create-drop`). This can be useful for demos and for testing if you -are careful but is probably not something you want to be on the classpath in production. +In addition, a file named `import.sql` in the root of the classpath is executed on startup if Hibernate creates the schema from scratch (that is, if the `ddl-auto` property is set to `create` or `create-drop`). +This can be useful for demos and for testing if you are careful but is probably not something you want to be on the classpath in production. It is a Hibernate feature (and has nothing to do with Spring). + [[howto-initialize-a-database-using-spring-jdbc]] === Initialize a Database -Spring Boot can automatically create the schema (DDL scripts) of your `DataSource` and -initialize it (DML scripts). It loads SQL from the standard root classpath locations: -`schema.sql` and `data.sql`, respectively. In addition, Spring Boot processes the -`schema-$\{platform}.sql` and `data-$\{platform}.sql` files (if present), where `platform` -is the value of `spring.datasource.platform`. This allows you to switch to -database-specific scripts if necessary. For example, you might choose to set it to the -vendor name of the database (`hsqldb`, `h2`, `oracle`, `mysql`, `postgresql`, and so on). +Spring Boot can automatically create the schema (DDL scripts) of your `DataSource` and initialize it (DML scripts). +It loads SQL from the standard root classpath locations: `schema.sql` and `data.sql`, respectively. +In addition, Spring Boot processes the `schema-$\{platform}.sql` and `data-$\{platform}.sql` files (if present), where `platform` is the value of `spring.datasource.platform`. +This allows you to switch to database-specific scripts if necessary. +For example, you might choose to set it to the vendor name of the database (`hsqldb`, `h2`, `oracle`, `mysql`, `postgresql`, and so on). [NOTE] ==== -Spring Boot automatically creates the schema of an embedded `DataSource`. This behaviour -can be customized by using the `spring.datasource.initialization-mode` property. For -instance, if you want to always initialize the `DataSource` regardless of its type: +Spring Boot automatically creates the schema of an embedded `DataSource`. +This behavior can be customized by using the `spring.datasource.initialization-mode` property. +For instance, if you want to always initialize the `DataSource` regardless of its type: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2259,157 +1867,130 @@ instance, if you want to always initialize the `DataSource` regardless of its ty ---- ==== -By default, Spring Boot enables the fail-fast feature of the Spring JDBC initializer. This -means that, if the scripts cause exceptions, the application fails to start. You can tune -that behavior by setting `spring.datasource.continue-on-error`. +By default, Spring Boot enables the fail-fast feature of the Spring JDBC initializer. +This means that, if the scripts cause exceptions, the application fails to start. +You can tune that behavior by setting `spring.datasource.continue-on-error`. -NOTE: In a JPA-based app, you can choose to let Hibernate create the schema or use -`schema.sql`, but you cannot do both. Make sure to disable -`spring.jpa.hibernate.ddl-auto` if you use `schema.sql`. +NOTE: In a JPA-based app, you can choose to let Hibernate create the schema or use `schema.sql`, but you cannot do both. +Make sure to disable `spring.jpa.hibernate.ddl-auto` if you use `schema.sql`. [[howto-initialize-a-spring-batch-database]] === Initialize a Spring Batch Database -If you use Spring Batch, it comes pre-packaged with SQL initialization scripts for most -popular database platforms. Spring Boot can detect your database type and execute those -scripts on startup. If you use an embedded database, this happens by default. You can also -enable it for any database type, as shown in the following example: +If you use Spring Batch, it comes pre-packaged with SQL initialization scripts for most popular database platforms. +Spring Boot can detect your database type and execute those scripts on startup. +If you use an embedded database, this happens by default. +You can also enable it for any database type, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- spring.batch.initialize-schema=always ---- -You can also switch off the initialization explicitly by setting -`spring.batch.initialize-schema=never`. +You can also switch off the initialization explicitly by setting `spring.batch.initialize-schema=never`. [[howto-use-a-higher-level-database-migration-tool]] === Use a Higher-level Database Migration Tool -Spring Boot supports two higher-level migration tools: https://flywaydb.org/[Flyway] -and https://www.liquibase.org/[Liquibase]. +Spring Boot supports two higher-level migration tools: https://flywaydb.org/[Flyway] and https://www.liquibase.org/[Liquibase]. + + [[howto-execute-flyway-database-migrations-on-startup]] ==== Execute Flyway Database Migrations on Startup -To automatically run Flyway database migrations on startup, add the -`org.flywaydb:flyway-core` to your classpath. +To automatically run Flyway database migrations on startup, add the `org.flywaydb:flyway-core` to your classpath. -The migrations are scripts in the form `V__.sql` (with `` an -underscore-separated version, such as '`1`' or '`2_1`'). By default, they are in a folder -called `classpath:db/migration`, but you can modify that location by setting -`spring.flyway.locations`. This is a comma-separated list of one or more `classpath:` -or `filesystem:` locations. For example, the following configuration would search for -scripts in both the default classpath location and the `/opt/migration` directory: +The migrations are scripts in the form `V__.sql` (with `` an underscore-separated version, such as '`1`' or '`2_1`'). +By default, they are in a folder called `classpath:db/migration`, but you can modify that location by setting `spring.flyway.locations`. +This is a comma-separated list of one or more `classpath:` or `filesystem:` locations. +For example, the following configuration would search for scripts in both the default classpath location and the `/opt/migration` directory: [source,properties,indent=0] ---- spring.flyway.locations=classpath:db/migration,filesystem:/opt/migration ---- -You can also add a special `\{vendor}` placeholder to use vendor-specific scripts. Assume -the following: +You can also add a special `\{vendor}` placeholder to use vendor-specific scripts. +Assume the following: [source,properties,indent=0] ---- spring.flyway.locations=classpath:db/migration/\{vendor} ---- -Rather than using `db/migration`, the preceding configuration sets the folder to use -according to the type of the database (such as `db/migration/mysql` for MySQL). The list -of supported databases is available in -{sc-spring-boot}/jdbc/DatabaseDriver.{sc-ext}[`DatabaseDriver`]. +Rather than using `db/migration`, the preceding configuration sets the folder to use according to the type of the database (such as `db/migration/mysql` for MySQL). +The list of supported databases is available in {sc-spring-boot}/jdbc/DatabaseDriver.{sc-ext}[`DatabaseDriver`]. -{sc-spring-boot-autoconfigure}/flyway/FlywayProperties.{sc-ext}[`FlywayProperties`] -provides most of Flyway's settings and a small set of additional properties that can be -used to disable the migrations or switch off the location checking. If you need more -control over the configuration, consider registering a `FlywayConfigurationCustomizer` -bean. +{sc-spring-boot-autoconfigure}/flyway/FlywayProperties.{sc-ext}[`FlywayProperties`] provides most of Flyway's settings and a small set of additional properties that can be used to disable the migrations or switch off the location checking. +If you need more control over the configuration, consider registering a `FlywayConfigurationCustomizer` bean. -Spring Boot calls `Flyway.migrate()` to perform the database migration. If you would like -more control, provide a `@Bean` that implements -{sc-spring-boot-autoconfigure}/flyway/FlywayMigrationStrategy.{sc-ext}[`FlywayMigrationStrategy`]. +Spring Boot calls `Flyway.migrate()` to perform the database migration. +If you would like more control, provide a `@Bean` that implements {sc-spring-boot-autoconfigure}/flyway/FlywayMigrationStrategy.{sc-ext}[`FlywayMigrationStrategy`]. Flyway supports SQL and Java https://flywaydb.org/documentation/callbacks.html[callbacks]. -To use SQL-based callbacks, place the callback scripts in the `classpath:db/migration` -folder. To use Java-based callbacks, create one or more beans that implement -`Callback`. Any such beans are automatically registered with `Flyway`. They can be -ordered by using `@Order` or by implementing `Ordered`. Beans that implement the -deprecated `FlywayCallback` interface can also be detected, however they cannot be used -alongside `Callback` beans. +To use SQL-based callbacks, place the callback scripts in the `classpath:db/migration` folder. +To use Java-based callbacks, create one or more beans that implement `Callback`. +Any such beans are automatically registered with `Flyway`. +They can be ordered by using `@Order` or by implementing `Ordered`. +Beans that implement the deprecated `FlywayCallback` interface can also be detected, however they cannot be used alongside `Callback` beans. -By default, Flyway autowires the (`@Primary`) `DataSource` in your context and -uses that for migrations. If you like to use a different `DataSource`, you can create -one and mark its `@Bean` as `@FlywayDataSource`. If you do so and want two data sources, -remember to create another one and mark it as `@Primary`. Alternatively, you can use -Flyway's native `DataSource` by setting `spring.flyway.[url,user,password]` -in external properties. Setting either `spring.flyway.url` or `spring.flyway.user` -is sufficient to cause Flyway to use its own `DataSource`. If any of the three -properties has not be set, the value of its equivalent `spring.datasource` property will -be used. +By default, Flyway autowires the (`@Primary`) `DataSource` in your context and uses that for migrations. +If you like to use a different `DataSource`, you can create one and mark its `@Bean` as `@FlywayDataSource`. +If you do so and want two data sources, remember to create another one and mark it as `@Primary`. +Alternatively, you can use Flyway's native `DataSource` by setting `spring.flyway.[url,user,password]` in external properties. +Setting either `spring.flyway.url` or `spring.flyway.user` is sufficient to cause Flyway to use its own `DataSource`. +If any of the three properties has not be set, the value of its equivalent `spring.datasource` property will be used. -There is a {github-code}/spring-boot-samples/spring-boot-sample-flyway[Flyway sample] so -that you can see how to set things up. +There is a {github-code}/spring-boot-samples/spring-boot-sample-flyway[Flyway sample] so that you can see how to set things up. -You can also use Flyway to provide data for specific scenarios. For example, you can -place test-specific migrations in `src/test/resources` and they are run only when your -application starts for testing. Also, you can use profile-specific configuration to -customize `spring.flyway.locations` so that certain migrations run only when a particular -profile is active. For example, in `application-dev.properties`, you might specify the -following setting: +You can also use Flyway to provide data for specific scenarios. +For example, you can place test-specific migrations in `src/test/resources` and they are run only when your application starts for testing. +Also, you can use profile-specific configuration to customize `spring.flyway.locations` so that certain migrations run only when a particular profile is active. +For example, in `application-dev.properties`, you might specify the following setting: [source,properties,indent=0] ---- spring.flyway.locations=classpath:/db/migration,classpath:/dev/db/migration ---- -With that setup, migrations in `dev/db/migration` run only when the `dev` profile is -active. +With that setup, migrations in `dev/db/migration` run only when the `dev` profile is active. [[howto-execute-liquibase-database-migrations-on-startup]] ==== Execute Liquibase Database Migrations on Startup -To automatically run Liquibase database migrations on startup, add the -`org.liquibase:liquibase-core` to your classpath. +To automatically run Liquibase database migrations on startup, add the `org.liquibase:liquibase-core` to your classpath. -By default, the master change log is read from `db/changelog/db.changelog-master.yaml`, -but you can change the location by setting `spring.liquibase.change-log`. In addition to -YAML, Liquibase also supports JSON, XML, and SQL change log formats. +By default, the master change log is read from `db/changelog/db.changelog-master.yaml`, but you can change the location by setting `spring.liquibase.change-log`. +In addition to YAML, Liquibase also supports JSON, XML, and SQL change log formats. -By default, Liquibase autowires the (`@Primary`) `DataSource` in your context and uses -that for migrations. If you need to use a different `DataSource`, you can create one and -mark its `@Bean` as `@LiquibaseDataSource`. If you do so and you want two data sources, -remember to create another one and mark it as `@Primary`. Alternatively, you can use -Liquibase's native `DataSource` by setting `spring.liquibase.[url,user,password]` in -external properties. Setting either `spring.liquibase.url` or `spring.liquibase.user` -is sufficient to cause Liquibase to use its own `DataSource`. If any of the three -properties has not be set, the value of its equivalent `spring.datasource` property will -be used. +By default, Liquibase autowires the (`@Primary`) `DataSource` in your context and uses that for migrations. +If you need to use a different `DataSource`, you can create one and mark its `@Bean` as `@LiquibaseDataSource`. +If you do so and you want two data sources, remember to create another one and mark it as `@Primary`. +Alternatively, you can use Liquibase's native `DataSource` by setting `spring.liquibase.[url,user,password]` in external properties. +Setting either `spring.liquibase.url` or `spring.liquibase.user` is sufficient to cause Liquibase to use its own `DataSource`. +If any of the three properties has not be set, the value of its equivalent `spring.datasource` property will be used. -See -{sc-spring-boot-autoconfigure}/liquibase/LiquibaseProperties.{sc-ext}[`LiquibaseProperties`] -for details about available settings such as contexts, the default schema, and others. +See {sc-spring-boot-autoconfigure}/liquibase/LiquibaseProperties.{sc-ext}[`LiquibaseProperties`] for details about available settings such as contexts, the default schema, and others. -There is a {github-code}/spring-boot-samples/spring-boot-sample-liquibase[Liquibase -sample] so that you can see how to set things up. +There is a {github-code}/spring-boot-samples/spring-boot-sample-liquibase[Liquibase sample] so that you can see how to set things up. [[howto-messaging]] == Messaging +Spring Boot offers a number of starters that include messaging. +This section answers questions that arise from using messaging with Spring Boot. + -Spring Boot offers a number of starters that include messaging. This section answers -questions that arise from using messaging with Spring Boot. [[howto-jms-disable-transaction]] === Disable Transacted JMS Session -If your JMS broker does not support transacted sessions, you have to disable the -support of transactions altogether. If you create your own `JmsListenerContainerFactory`, -there is nothing to do, since, by default it cannot be transacted. If you want to use -the `DefaultJmsListenerContainerFactoryConfigurer` to reuse Spring Boot's default, you -can disable transacted sessions, as follows: +If your JMS broker does not support transacted sessions, you have to disable the support of transactions altogether. +If you create your own `JmsListenerContainerFactory`, there is nothing to do, since, by default it cannot be transacted. +If you want to use the `DefaultJmsListenerContainerFactoryConfigurer` to reuse Spring Boot's default, you can disable transacted sessions, as follows: [source,java,indent=0] ---- @@ -2426,129 +2007,91 @@ can disable transacted sessions, as follows: } ---- -The preceding example overrides the default factory, and it should be applied to any -other factory that your application defines, if any. +The preceding example overrides the default factory, and it should be applied to any other factory that your application defines, if any. [[howto-batch-applications]] == Batch Applications - This section answers questions that arise from using Spring Batch with Spring Boot. -NOTE: By default, batch applications require a `DataSource` to store job details. If you -want to deviate from that, you need to implement `BatchConfigurer`. See -{spring-batch-javadoc}/core/configuration/annotation/EnableBatchProcessing.html[The -Javadoc of `@EnableBatchProcessing`] for more details. +NOTE: By default, batch applications require a `DataSource` to store job details. +If you want to deviate from that, you need to implement `BatchConfigurer`. +See {spring-batch-javadoc}/core/configuration/annotation/EnableBatchProcessing.html[The Javadoc of `@EnableBatchProcessing`] for more details. -For more about Spring Batch, see the https://projects.spring.io/spring-batch/[Spring Batch -project page]. +For more about Spring Batch, see the https://projects.spring.io/spring-batch/[Spring Batch project page]. [[howto-execute-spring-batch-jobs-on-startup]] === Execute Spring Batch Jobs on Startup -Spring Batch auto-configuration is enabled by adding `@EnableBatchProcessing` -(from Spring Batch) somewhere in your context. +Spring Batch auto-configuration is enabled by adding `@EnableBatchProcessing` (from Spring Batch) somewhere in your context. -By default, it executes *all* `Jobs` in the application context on startup (see -{sc-spring-boot-autoconfigure}/batch/JobLauncherCommandLineRunner.{sc-ext}[JobLauncherCommandLineRunner] -for details). You can narrow down to a specific job or jobs by specifying -`spring.batch.job.names` (which takes a comma-separated list of job name patterns). +By default, it executes *all* `Jobs` in the application context on startup (see {sc-spring-boot-autoconfigure}/batch/JobLauncherCommandLineRunner.{sc-ext}[JobLauncherCommandLineRunner] for details). +You can narrow down to a specific job or jobs by specifying `spring.batch.job.names` (which takes a comma-separated list of job name patterns). [TIP] .Specifying job parameters on the command line ==== -Unlike command line option arguments that -<> (i.e. by starting with `--`, such as -`--my-property=value`), job parameters have to be specified on the command line without -dashes (e.g. `jobParam=value`). +Unlike command line option arguments that <> (i.e. by starting with `--`, such as `--my-property=value`), job parameters have to be specified on the command line without dashes (e.g. `jobParam=value`). ==== -If the application context includes a `JobRegistry`, the jobs in -`spring.batch.job.names` are looked up in the registry instead of being autowired from the -context. This is a common pattern with more complex systems, where multiple jobs are -defined in child contexts and registered centrally. +If the application context includes a `JobRegistry`, the jobs in `spring.batch.job.names` are looked up in the registry instead of being autowired from the context. +This is a common pattern with more complex systems, where multiple jobs are defined in child contexts and registered centrally. -See -{sc-spring-boot-autoconfigure}/batch/BatchAutoConfiguration.{sc-ext}[BatchAutoConfiguration] -and -https://github.com/spring-projects/spring-batch/blob/master/spring-batch-core/src/main/java/org/springframework/batch/core/configuration/annotation/EnableBatchProcessing.java[@EnableBatchProcessing] -for more details. +See {sc-spring-boot-autoconfigure}/batch/BatchAutoConfiguration.{sc-ext}[BatchAutoConfiguration] and https://github.com/spring-projects/spring-batch/blob/master/spring-batch-core/src/main/java/org/springframework/batch/core/configuration/annotation/EnableBatchProcessing.java[@EnableBatchProcessing] for more details. [[howto-actuator]] == Actuator +Spring Boot includes the Spring Boot Actuator. This section answers questions that often arise from its use. + -Spring Boot includes the Spring Boot Actuator. This section answers questions that often -arise from its use. [[howto-change-the-http-port-or-address-of-the-actuator-endpoints]] === Change the HTTP Port or Address of the Actuator Endpoints -In a standalone application, the Actuator HTTP port defaults to the same as the main HTTP -port. To make the application listen on a different port, set the external property: -`management.server.port`. To listen on a completely different network address (such as -when you have an internal network for management and an external one for user -applications), you can also set `management.server.address` to a valid IP address to which -the server is able to bind. +In a standalone application, the Actuator HTTP port defaults to the same as the main HTTP port. +To make the application listen on a different port, set the external property: `management.server.port`. +To listen on a completely different network address (such as when you have an internal network for management and an external one for user applications), you can also set `management.server.address` to a valid IP address to which the server is able to bind. -For more detail, see the -{sc-spring-boot-actuator-autoconfigure}/web/server/ManagementServerProperties.{sc-ext}[`ManagementServerProperties`] -source code and -"`<>`" -in the "`Production-ready features`" section. +For more detail, see the {sc-spring-boot-actuator-autoconfigure}/web/server/ManagementServerProperties.{sc-ext}[`ManagementServerProperties`] source code and "`<>`" in the "`Production-ready features`" section. [[howto-customize-the-whitelabel-error-page]] === Customize the '`whitelabel`' Error Page -Spring Boot installs a '`whitelabel`' error page that you see in a browser client if -you encounter a server error (machine clients consuming JSON and other media types should -see a sensible response with the right error code). +Spring Boot installs a '`whitelabel`' error page that you see in a browser client if you encounter a server error (machine clients consuming JSON and other media types should see a sensible response with the right error code). NOTE: Set `server.error.whitelabel.enabled=false` to switch the default error page off. -Doing so restores the default of the servlet container that you are using. Note that -Spring Boot still tries to resolve the error view, so you should probably add your own -error page rather than disabling it completely. +Doing so restores the default of the servlet container that you are using. +Note that Spring Boot still tries to resolve the error view, so you should probably add your own error page rather than disabling it completely. -Overriding the error page with your own depends on the templating technology that you -use. For example, if you use Thymeleaf, you can add an `error.html` template. -If you use FreeMarker, you can add an `error.ftl` template. In general, you -need a `View` that resolves with a name of `error` or a `@Controller` that handles -the `/error` path. Unless you replaced some of the default configuration, you should find -a `BeanNameViewResolver` in your `ApplicationContext`, so a `@Bean` named `error` would -be a simple way of doing that. See -{sc-spring-boot-autoconfigure}/web/servlet/error/ErrorMvcAutoConfiguration.{sc-ext}[`ErrorMvcAutoConfiguration`] -for more options. +Overriding the error page with your own depends on the templating technology that you use. +For example, if you use Thymeleaf, you can add an `error.html` template. +If you use FreeMarker, you can add an `error.ftl` template. +In general, you need a `View` that resolves with a name of `error` or a `@Controller` that handles the `/error` path. +Unless you replaced some of the default configuration, you should find a `BeanNameViewResolver` in your `ApplicationContext`, so a `@Bean` named `error` would be a simple way of doing that. +See {sc-spring-boot-autoconfigure}/web/servlet/error/ErrorMvcAutoConfiguration.{sc-ext}[`ErrorMvcAutoConfiguration`] for more options. -See also the section on "`<>`" for details -of how to register handlers in the servlet container. +See also the section on "`<>`" for details of how to register handlers in the servlet container. [[howto-sanitize-sensible-values]] === Sanitize sensible values -Information returned by the `env` and `configprops` endpoints can be somewhat sensitive -so keys matching a certain pattern are sanitized by default (i.e. their values are -replaced by `+******+`). +Information returned by the `env` and `configprops` endpoints can be somewhat sensitive so keys matching a certain pattern are sanitized by default (i.e. their values are replaced by `+******+`). -Spring Boot uses sensible defaults for such keys: for instance, any key ending with the -word "password", "secret", "key" or "token" is sanitized. It is also possible to use a -regular expression instead, such as `+*credentials.*+` to sanitize any key that holds the -word `credentials` as part of the key. +Spring Boot uses sensible defaults for such keys: for instance, any key ending with the word "password", "secret", "key" or "token" is sanitized. +It is also possible to use a regular expression instead, such as `+*credentials.*+` to sanitize any key that holds the word `credentials` as part of the key. -The patterns to use can be customized using the `management.endpoint.env.keys-to-sanitize` -and `management.endpoint.configprops.keys-to-sanitize` respectively. +The patterns to use can be customized using the `management.endpoint.env.keys-to-sanitize` and `management.endpoint.configprops.keys-to-sanitize` respectively. [[howto-security]] == Security - -This section addresses questions about security when working with Spring Boot, including -questions that arise from using Spring Security with Spring Boot. +This section addresses questions about security when working with Spring Boot, including questions that arise from using Spring Security with Spring Boot. For more about Spring Security, see the {spring-security}[Spring Security project page]. @@ -2556,17 +2099,13 @@ For more about Spring Security, see the {spring-security}[Spring Security projec [[howto-switch-off-spring-boot-security-configuration]] === Switch off the Spring Boot Security Configuration -If you define a `@Configuration` with a `WebSecurityConfigurerAdapter` in your application, -it switches off the default webapp security settings in Spring Boot. +If you define a `@Configuration` with a `WebSecurityConfigurerAdapter` in your application, it switches off the default webapp security settings in Spring Boot. [[howto-change-the-user-details-service-and-add-user-accounts]] === Change the UserDetailsService and Add User Accounts -If you provide a `@Bean` of type `AuthenticationManager`, `AuthenticationProvider`, -or `UserDetailsService`, the default `@Bean` for `InMemoryUserDetailsManager` is not -created, so you have the full feature set of Spring Security available (such as -https://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#jc-authentication[various -authentication options]). +If you provide a `@Bean` of type `AuthenticationManager`, `AuthenticationProvider`, or `UserDetailsService`, the default `@Bean` for `InMemoryUserDetailsManager` is not created. +This means you have the full feature set of Spring Security available (such as https://docs.spring.io/spring-security/site/docs/current/reference/htmlsingle/#jc-authentication[various authentication options]). The easiest way to add user accounts is to provide your own `UserDetailsService` bean. @@ -2574,15 +2113,10 @@ The easiest way to add user accounts is to provide your own `UserDetailsService` [[howto-enable-https]] === Enable HTTPS When Running behind a Proxy Server -Ensuring that all your main endpoints are only available over HTTPS is an important -chore for any application. If you use Tomcat as a servlet container, then -Spring Boot adds Tomcat's own `RemoteIpValve` automatically if it detects some -environment settings, and you should be able to rely on the `HttpServletRequest` to -report whether it is secure or not (even downstream of a proxy server that handles the -real SSL termination). The standard behavior is determined by the presence or absence of -certain request headers (`x-forwarded-for` and `x-forwarded-proto`), whose names are -conventional, so it should work with most front-end proxies. You can switch on the valve -by adding some entries to `application.properties`, as shown in the following example: +Ensuring that all your main endpoints are only available over HTTPS is an important chore for any application. +If you use Tomcat as a servlet container, then Spring Boot adds Tomcat's own `RemoteIpValve` automatically if it detects some environment settings, and you should be able to rely on the `HttpServletRequest` to report whether it is secure or not (even downstream of a proxy server that handles the real SSL termination). +The standard behavior is determined by the presence or absence of certain request headers (`x-forwarded-for` and `x-forwarded-proto`), whose names are conventional, so it should work with most front-end proxies. +You can switch on the valve by adding some entries to `application.properties`, as shown in the following example: [source,properties,indent=0] ---- @@ -2590,12 +2124,9 @@ by adding some entries to `application.properties`, as shown in the following ex server.tomcat.protocol-header=x-forwarded-proto ---- -(The presence of either of those properties switches on the valve. Alternatively, you can -add the `RemoteIpValve` by adding a `TomcatServletWebServerFactory` bean.) +(The presence of either of those properties switches on the valve. Alternatively, you can add the `RemoteIpValve` by adding a `TomcatServletWebServerFactory` bean.) -To configure Spring Security to require a secure channel for all (or some) -requests, consider adding your own `WebSecurityConfigurerAdapter` that adds the following -`HttpSecurity` configuration: +To configure Spring Security to require a secure channel for all (or some) requests, consider adding your own `WebSecurityConfigurerAdapter` that adds the following `HttpSecurity` configuration: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2612,79 +2143,64 @@ requests, consider adding your own `WebSecurityConfigurerAdapter` that adds the ---- + [[howto-hotswapping]] == Hot Swapping - Spring Boot supports hot swapping. This section answers questions about how it works. [[howto-reload-static-content]] === Reload Static Content -There are several options for hot reloading. The recommended approach is to use -<>, as it provides -additional development-time features, such as support for fast application restarts -and LiveReload as well as sensible development-time configuration (such as template -caching). Devtools works by monitoring the classpath for changes. This means that static -resource changes must be "built" for the change to take effect. By default, this happens -automatically in Eclipse when you save your changes. In IntelliJ IDEA, the Make Project -command triggers the necessary build. Due to the -<>, changes to static resources do not trigger a restart of your application. +There are several options for hot reloading. +The recommended approach is to use <>, as it provides additional development-time features, such as support for fast application restarts and LiveReload as well as sensible development-time configuration (such as template caching). +Devtools works by monitoring the classpath for changes. +This means that static resource changes must be "built" for the change to take effect. +By default, this happens automatically in Eclipse when you save your changes. +In IntelliJ IDEA, the Make Project command triggers the necessary build. +Due to the <>, changes to static resources do not trigger a restart of your application. They do, however, trigger a live reload. -Alternatively, running in an IDE (especially with debugging on) is a good way to do -development (all modern IDEs allow reloading of static resources and usually also allow -hot-swapping of Java class changes). +Alternatively, running in an IDE (especially with debugging on) is a good way to do development (all modern IDEs allow reloading of static resources and usually also allow hot-swapping of Java class changes). -Finally, the <> can -be configured (see the `addResources` property) to support running from the command line -with reloading of static files directly from source. You can use that with an external -css/js compiler process if you are writing that code with higher-level tools. +Finally, the <> can be configured (see the `addResources` property) to support running from the command line with reloading of static files directly from source. +You can use that with an external css/js compiler process if you are writing that code with higher-level tools. [[howto-reload-thymeleaf-template-content]] === Reload Templates without Restarting the Container -Most of the templating technologies supported by Spring Boot include a configuration -option to disable caching (described later in this document). If you use the -`spring-boot-devtools` module, these properties are -<> -for you at development time. +Most of the templating technologies supported by Spring Boot include a configuration option to disable caching (described later in this document). +If you use the `spring-boot-devtools` module, these properties are <> for you at development time. [[howto-reload-thymeleaf-content]] ==== Thymeleaf Templates -If you use Thymeleaf, set `spring.thymeleaf.cache` to `false`. See -{sc-spring-boot-autoconfigure}/thymeleaf/ThymeleafAutoConfiguration.{sc-ext}[`ThymeleafAutoConfiguration`] -for other Thymeleaf customization options. +If you use Thymeleaf, set `spring.thymeleaf.cache` to `false`. +See {sc-spring-boot-autoconfigure}/thymeleaf/ThymeleafAutoConfiguration.{sc-ext}[`ThymeleafAutoConfiguration`] for other Thymeleaf customization options. [[howto-reload-freemarker-content]] ==== FreeMarker Templates -If you use FreeMarker, set `spring.freemarker.cache` to `false`. See -{sc-spring-boot-autoconfigure}/freemarker/FreeMarkerAutoConfiguration.{sc-ext}[`FreeMarkerAutoConfiguration`] -for other FreeMarker customization options. +If you use FreeMarker, set `spring.freemarker.cache` to `false`. +See {sc-spring-boot-autoconfigure}/freemarker/FreeMarkerAutoConfiguration.{sc-ext}[`FreeMarkerAutoConfiguration`] for other FreeMarker customization options. [[howto-reload-groovy-template-content]] ==== Groovy Templates -If you use Groovy templates, set `spring.groovy.template.cache` to `false`. See -{sc-spring-boot-autoconfigure}/groovy/template/GroovyTemplateAutoConfiguration.{sc-ext}[`GroovyTemplateAutoConfiguration`] -for other Groovy customization options. +If you use Groovy templates, set `spring.groovy.template.cache` to `false`. +See {sc-spring-boot-autoconfigure}/groovy/template/GroovyTemplateAutoConfiguration.{sc-ext}[`GroovyTemplateAutoConfiguration`] for other Groovy customization options. [[howto-reload-fast-restart]] === Fast Application Restarts The `spring-boot-devtools` module includes support for automatic application restarts. -While not as fast as technologies such as -https://zeroturnaround.com/software/jrebel/[JRebel] it is usually significantly faster than -a "`cold start`". You should probably give it a try before investigating some of the more -complex reload options discussed later in this document. +While not as fast as technologies such as https://zeroturnaround.com/software/jrebel/[JRebel] it is usually significantly faster than a "`cold start`". +You should probably give it a try before investigating some of the more complex reload options discussed later in this document. For more details, see the <> section. @@ -2693,28 +2209,24 @@ For more details, see the <> section [[howto-reload-java-classes-without-restarting]] === Reload Java Classes without Restarting the Container Many modern IDEs (Eclipse, IDEA, and others) support hot swapping of bytecode. -Consequently, if you make a change that does not affect class or method signatures, it -should reload cleanly with no side effects. +Consequently, if you make a change that does not affect class or method signatures, it should reload cleanly with no side effects. [[howto-build]] == Build - -Spring Boot includes build plugins for Maven and Gradle. This section answers common -questions about these plugins. +Spring Boot includes build plugins for Maven and Gradle. +This section answers common questions about these plugins. [[howto-build-info]] === Generate Build Information -Both the Maven plugin and the Gradle plugin allow generating build information containing -the coordinates, name, and version of the project. The plugins can also be configured -to add additional properties through configuration. When such a file is present, -Spring Boot auto-configures a `BuildProperties` bean. +Both the Maven plugin and the Gradle plugin allow generating build information containing the coordinates, name, and version of the project. +The plugins can also be configured to add additional properties through configuration. +When such a file is present, Spring Boot auto-configures a `BuildProperties` bean. -To generate build information with Maven, add an execution for the `build-info` goal, as -shown in the following example: +To generate build information with Maven, add an execution for the `build-info` goal, as shown in the following example: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2736,8 +2248,7 @@ shown in the following example: ---- -TIP: See the {spring-boot-maven-plugin-site}[Spring Boot Maven Plugin documentation] -for more details. +TIP: See the {spring-boot-maven-plugin-site}[Spring Boot Maven Plugin documentation] for more details. The following example does the same with Gradle: @@ -2748,20 +2259,16 @@ The following example does the same with Gradle: } ---- -TIP: See the -{spring-boot-gradle-plugin-reference}/#integrating-with-actuator-build-info[Spring Boot -Gradle Plugin documentation] for more details. +TIP: See the {spring-boot-gradle-plugin-reference}/#integrating-with-actuator-build-info[Spring Boot Gradle Plugin documentation] for more details. [[howto-git-info]] === Generate Git Information +Both Maven and Gradle allow generating a `git.properties` file containing information about the state of your `git` source code repository when the project was built. -Both Maven and Gradle allow generating a `git.properties` file containing information -about the state of your `git` source code repository when the project was built. - -For Maven users, the `spring-boot-starter-parent` POM includes a pre-configured plugin to -generate a `git.properties` file. To use it, add the following declaration to your POM: +For Maven users, the `spring-boot-starter-parent` POM includes a pre-configured plugin to generate a `git.properties` file. +To use it, add the following declaration to your POM: [source,xml,indent=0] ---- @@ -2775,9 +2282,7 @@ generate a `git.properties` file. To use it, add the following declaration to yo ---- -Gradle users can achieve the same result by using the -https://plugins.gradle.org/plugin/com.gorylenko.gradle-git-properties[`gradle-git-properties`] -plugin, as shown in the following example: +Gradle users can achieve the same result by using the https://plugins.gradle.org/plugin/com.gorylenko.gradle-git-properties[`gradle-git-properties`] plugin, as shown in the following example: [source,groovy,indent=0] ---- @@ -2786,22 +2291,17 @@ plugin, as shown in the following example: } ---- -TIP: The commit time in `git.properties` is expected to match the following format: -`yyyy-MM-dd'T'HH:mm:ssZ`. This is the default format for both plugins listed above. Using -this format lets the time be parsed into a `Date` and its format, when serialized to JSON, -to be controlled by Jackson's date serialization configuration settings. +TIP: The commit time in `git.properties` is expected to match the following format: `yyyy-MM-dd'T'HH:mm:ssZ`. +This is the default format for both plugins listed above. +Using this format lets the time be parsed into a `Date` and its format, when serialized to JSON, to be controlled by Jackson's date serialization configuration settings. [[howto-customize-dependency-versions]] === Customize Dependency Versions -If you use a Maven build that inherits directly or indirectly from -`spring-boot-dependencies` (for instance, `spring-boot-starter-parent`) but you want to -override a specific third-party dependency, you can add appropriate `` -elements. Browse the -{github-code}/spring-boot-project/spring-boot-dependencies/pom.xml[`spring-boot-dependencies`] -POM for a complete list of properties. For example, to pick a different `slf4j` version, -you would add the following property: +If you use a Maven build that inherits directly or indirectly from `spring-boot-dependencies` (for instance, `spring-boot-starter-parent`) but you want to override a specific third-party dependency, you can add appropriate `` elements. +Browse the {github-code}/spring-boot-project/spring-boot-dependencies/pom.xml[`spring-boot-dependencies`] POM for a complete list of properties. +For example, to pick a different `slf4j` version, you would add the following property: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2810,22 +2310,20 @@ you would add the following property: ---- -NOTE: Doing so only works if your Maven project inherits (directly or indirectly) from -`spring-boot-dependencies`. If you have added `spring-boot-dependencies` in your -own `dependencyManagement` section with `import`, you have to redefine -the artifact yourself instead of overriding the property. +NOTE: Doing so only works if your Maven project inherits (directly or indirectly) from `spring-boot-dependencies`. +If you have added `spring-boot-dependencies` in your own `dependencyManagement` section with `import`, you have to redefine the artifact yourself instead of overriding the property. + +WARNING: Each Spring Boot release is designed and tested against this specific set of third-party dependencies. +Overriding versions may cause compatibility issues. + +To override dependency versions in Gradle, see {spring-boot-gradle-plugin-reference}/#managing-dependencies-customizing[this section] of the Gradle plugin's documentation. -WARNING: Each Spring Boot release is designed and tested against this specific set of -third-party dependencies. Overriding versions may cause compatibility issues. -To override dependency versions in Gradle, see {spring-boot-gradle-plugin-reference}/#managing-dependencies-customizing[this section] -of the Gradle plugin's documentation. [[howto-create-an-executable-jar-with-maven]] === Create an Executable JAR with Maven -The `spring-boot-maven-plugin` can be used to create an executable "`fat`" JAR. If you -use the `spring-boot-starter-parent` POM, you can declare the plugin and your jars are -repackaged as follows: +The `spring-boot-maven-plugin` can be used to create an executable "`fat`" JAR. +If you use the `spring-boot-starter-parent` POM, you can declare the plugin and your jars are repackaged as follows: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2839,8 +2337,8 @@ repackaged as follows: ---- -If you do not use the parent POM, you can still use the plugin. However, you must -additionally add an `` section, as follows: +If you do not use the parent POM, you can still use the plugin. +However, you must additionally add an `` section, as follows: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2862,27 +2360,22 @@ additionally add an `` section, as follows: ---- -See the {spring-boot-maven-plugin-site}/usage.html[plugin documentation] for full usage -details. +See the {spring-boot-maven-plugin-site}/usage.html[plugin documentation] for full usage details. + [[howto-create-an-additional-executable-jar]] === Use a Spring Boot Application as a Dependency -Like a war file, a Spring Boot application is not intended to be used as a dependency. If -your application contains classes that you want to share with other projects, the -recommended approach is to move that code into a separate module. The separate module can -then be depended upon by your application and other projects. +Like a war file, a Spring Boot application is not intended to be used as a dependency. +If your application contains classes that you want to share with other projects, the recommended approach is to move that code into a separate module. +The separate module can then be depended upon by your application and other projects. -If you cannot rearrange your code as recommended above, Spring Boot's Maven and Gradle -plugins must be configured to produce a separate artifact that is suitable for use as a -dependency. The executable archive cannot be used as a dependency as the -<> packages application classes in `BOOT-INF/classes`. This means -that they cannot be found when the executable jar is used as a dependency. +If you cannot rearrange your code as recommended above, Spring Boot's Maven and Gradle plugins must be configured to produce a separate artifact that is suitable for use as a dependency. +The executable archive cannot be used as a dependency as the <> packages application classes in `BOOT-INF/classes`. +This means that they cannot be found when the executable jar is used as a dependency. -To produce the two artifacts, one that can be used as a dependency and one that is -executable, a classifier must be specified. This classifier is applied to the name of the -executable archive, leaving the default archive for use as a dependency. +To produce the two artifacts, one that can be used as a dependency and one that is executable, a classifier must be specified. +This classifier is applied to the name of the executable archive, leaving the default archive for use as a dependency. To configure a classifier of `exec` in Maven, you can use the following configuration: @@ -2906,20 +2399,15 @@ To configure a classifier of `exec` in Maven, you can use the following configur [[howto-extract-specific-libraries-when-an-executable-jar-runs]] === Extract Specific Libraries When an Executable Jar Runs Most nested libraries in an executable jar do not need to be unpacked in order to run. -However, certain libraries can have problems. For example, JRuby includes its own nested -jar support, which assumes that the `jruby-complete.jar` is always directly available as a -file in its own right. +However, certain libraries can have problems. +For example, JRuby includes its own nested jar support, which assumes that the `jruby-complete.jar` is always directly available as a file in its own right. -To deal with any problematic libraries, you can flag that specific nested jars should be -automatically unpacked when the executable jar first runs. Such nested jars are written -beneath the temporary directory identified by the `java.io.tmpdir` system property. +To deal with any problematic libraries, you can flag that specific nested jars should be automatically unpacked when the executable jar first runs. +Such nested jars are written beneath the temporary directory identified by the `java.io.tmpdir` system property. -WARNING: Care should be taken to ensure that your operating system is configured so that -it will not delete the jars that have been unpacked to the temporary directory while the -application is still running. +WARNING: Care should be taken to ensure that your operating system is configured so that it will not delete the jars that have been unpacked to the temporary directory while the application is still running. -For example, to indicate that JRuby should be flagged for unpacking by using the Maven -Plugin, you would add the following configuration: +For example, to indicate that JRuby should be flagged for unpacking by using the Maven Plugin, you would add the following configuration: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2945,13 +2433,10 @@ Plugin, you would add the following configuration: [[howto-create-a-nonexecutable-jar]] === Create a Non-executable JAR with Exclusions -Often, if you have an executable and a non-executable jar as two separate build products, -the executable version has additional configuration files that are not needed in a library -jar. For example, the `application.yml` configuration file might by excluded from the -non-executable JAR. +Often, if you have an executable and a non-executable jar as two separate build products, the executable version has additional configuration files that are not needed in a library jar. +For example, the `application.yml` configuration file might by excluded from the non-executable JAR. -In Maven, the executable jar must be the main artifact and you can add a classified jar -for the library, as follows: +In Maven, the executable jar must be the main artifact and you can add a classified jar for the library, as follows: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2987,33 +2472,25 @@ for the library, as follows: [[howto-remote-debug-maven-run]] === Remote Debug a Spring Boot Application Started with Maven -To attach a remote debugger to a Spring Boot application that was started with Maven, you -can use the `jvmArguments` property of the {spring-boot-maven-plugin-site}[maven plugin]. +To attach a remote debugger to a Spring Boot application that was started with Maven, you can use the `jvmArguments` property of the {spring-boot-maven-plugin-site}[maven plugin]. -See {spring-boot-maven-plugin-site}/examples/run-debug.html[this example] for more -details. +See {spring-boot-maven-plugin-site}/examples/run-debug.html[this example] for more details. [[howto-build-an-executable-archive-with-ant]] === Build an Executable Archive from Ant without Using `spring-boot-antlib` -To build with Ant, you need to grab dependencies, compile, and then create a jar or war -archive. To make it executable, you can either use the `spring-boot-antlib` -module or you can follow these instructions: +To build with Ant, you need to grab dependencies, compile, and then create a jar or war archive. +To make it executable, you can either use the `spring-boot-antlib` module or you can follow these instructions: -. If you are building a jar, package the application's classes and resources in a nested -`BOOT-INF/classes` directory. If you are building a war, package the application's -classes in a nested `WEB-INF/classes` directory as usual. -. Add the runtime dependencies in a nested `BOOT-INF/lib` directory for a jar or -`WEB-INF/lib` for a war. Remember *not* to compress the entries in the archive. -. Add the `provided` (embedded container) dependencies in a nested `BOOT-INF/lib` -directory for a jar or `WEB-INF/lib-provided` for a war. Remember *not* to compress the -entries in the archive. -. Add the `spring-boot-loader` classes at the root of the archive (so that the `Main-Class` -is available). -. Use the appropriate launcher (such as `JarLauncher` for a jar file) as a `Main-Class` -attribute in the manifest and specify the other properties it needs as manifest entries -- -principally, by setting a `Start-Class` property. +. If you are building a jar, package the application's classes and resources in a nested `BOOT-INF/classes` directory. + If you are building a war, package the application's classes in a nested `WEB-INF/classes` directory as usual. +. Add the runtime dependencies in a nested `BOOT-INF/lib` directory for a jar or `WEB-INF/lib` for a war. + Remember *not* to compress the entries in the archive. +. Add the `provided` (embedded container) dependencies in a nested `BOOT-INF/lib` directory for a jar or `WEB-INF/lib-provided` for a war. + Remember *not* to compress the entries in the archive. +. Add the `spring-boot-loader` classes at the root of the archive (so that the `Main-Class` is available). +. Use the appropriate launcher (such as `JarLauncher` for a jar file) as a `Main-Class` attribute in the manifest and specify the other properties it needs as manifest entries -- principally, by setting a `Start-Class` property. The following example shows how to build an executable archive with Ant: @@ -3042,9 +2519,7 @@ The following example shows how to build an executable archive with Ant: ---- -The {github-code}/spring-boot-samples/spring-boot-sample-ant[Ant Sample] has a -`build.xml` file with a `manual` task that should work if you run it with the following -command: +The {github-code}/spring-boot-samples/spring-boot-sample-ant[Ant Sample] has a `build.xml` file with a `manual` task that should work if you run it with the following command: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3062,7 +2537,6 @@ Then you can run the application with the following command: [[howto-traditional-deployment]] == Traditional Deployment - Spring Boot supports traditional deployment as well as more modern forms of deployment. This section answers common questions about traditional deployment. @@ -3071,16 +2545,11 @@ This section answers common questions about traditional deployment. [[howto-create-a-deployable-war-file]] === Create a Deployable War File -WARNING: Because Spring WebFlux does not strictly depend on the Servlet API and -applications are deployed by default on an embedded Reactor Netty server, -War deployment is not supported for WebFlux applications. +WARNING: Because Spring WebFlux does not strictly depend on the Servlet API and applications are deployed by default on an embedded Reactor Netty server, War deployment is not supported for WebFlux applications. -The first step in producing a deployable war file is to provide a -`SpringBootServletInitializer` subclass and override its `configure` method. Doing so -makes use of Spring Framework's Servlet 3.0 support and lets you configure your -application when it is launched by the servlet container. Typically, you should update -your application's main class to extend `SpringBootServletInitializer`, as shown in the -following example: +The first step in producing a deployable war file is to provide a `SpringBootServletInitializer` subclass and override its `configure` method. +Doing so makes use of Spring Framework's Servlet 3.0 support and lets you configure your application when it is launched by the servlet container. +Typically, you should update your application's main class to extend `SpringBootServletInitializer`, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3099,30 +2568,25 @@ following example: } ---- -The next step is to update your build configuration such that your project produces a war -file rather than a jar file. If you use Maven and `spring-boot-starter-parent` (which -configures Maven's war plugin for you), all you need to do is to modify `pom.xml` to -change the packaging to war, as follows: +The next step is to update your build configuration such that your project produces a war file rather than a jar file. +If you use Maven and `spring-boot-starter-parent` (which configures Maven's war plugin for you), all you need to do is to modify `pom.xml` to change the packaging to war, as follows: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- war ---- -If you use Gradle, you need to modify `build.gradle` to apply the war plugin to the -project, as follows: +If you use Gradle, you need to modify `build.gradle` to apply the war plugin to the project, as follows: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- apply plugin: 'war' ---- -The final step in the process is to ensure that the embedded servlet container does not -interfere with the servlet container to which the war file is deployed. To do so, you -need to mark the embedded servlet container dependency as being provided. +The final step in the process is to ensure that the embedded servlet container does not interfere with the servlet container to which the war file is deployed. +To do so, you need to mark the embedded servlet container dependency as being provided. -If you use Maven, the following example marks the servlet container (Tomcat, in this -case) as being provided: +If you use Maven, the following example marks the servlet container (Tomcat, in this case) as being provided: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3137,8 +2601,7 @@ case) as being provided: ---- -If you use Gradle, the following example marks the servlet container (Tomcat, in this -case) as being provided: +If you use Gradle, the following example marks the servlet container (Tomcat, in this case) as being provided: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3149,36 +2612,25 @@ case) as being provided: } ---- -TIP: `providedRuntime` is preferred to Gradle's `compileOnly` configuration. Among other -limitations, `compileOnly` dependencies are not on the test classpath, so any web-based -integration tests fail. +TIP: `providedRuntime` is preferred to Gradle's `compileOnly` configuration. +Among other limitations, `compileOnly` dependencies are not on the test classpath, so any web-based integration tests fail. -If you use the <>, -marking the embedded servlet container dependency as provided produces an executable war -file with the provided dependencies packaged in a `lib-provided` directory. This means -that, in addition to being deployable to a servlet container, you can also run your -application by using `java -jar` on the command line. +If you use the <>, marking the embedded servlet container dependency as provided produces an executable war file with the provided dependencies packaged in a `lib-provided` directory. +This means that, in addition to being deployable to a servlet container, you can also run your application by using `java -jar` on the command line. -TIP: Take a look at Spring Boot's sample applications for a -{github-code}/spring-boot-samples/spring-boot-sample-traditional/pom.xml[Maven-based -example] of the previously described configuration. +TIP: Take a look at Spring Boot's sample applications for a {github-code}/spring-boot-samples/spring-boot-sample-traditional/pom.xml[Maven-based example] of the previously described configuration. [[howto-convert-an-existing-application-to-spring-boot]] === Convert an Existing Application to Spring Boot -For a non-web application, it should be easy to convert an existing Spring application to -a Spring Boot application. To do so, throw away the code that creates your -`ApplicationContext` and replace it with calls to `SpringApplication` or -`SpringApplicationBuilder`. Spring MVC web applications are generally amenable to first -creating a deployable war application and then migrating it later to an executable war -or jar. See the https://spring.io/guides/gs/convert-jar-to-war/[Getting -Started Guide on Converting a jar to a war]. +For a non-web application, it should be easy to convert an existing Spring application to a Spring Boot application. +To do so, throw away the code that creates your `ApplicationContext` and replace it with calls to `SpringApplication` or `SpringApplicationBuilder`. +Spring MVC web applications are generally amenable to first creating a deployable war application and then migrating it later to an executable war or jar. +See the https://spring.io/guides/gs/convert-jar-to-war/[Getting Started Guide on Converting a jar to a war]. -To create a deployable war by extending `SpringBootServletInitializer` (for example, in a -class called `Application`) and adding the Spring Boot `@SpringBootApplication` -annotation, use code similar to that shown in the following example: +To create a deployable war by extending `SpringBootServletInitializer` (for example, in a class called `Application`) and adding the Spring Boot `@SpringBootApplication` annotation, use code similar to that shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3197,29 +2649,21 @@ annotation, use code similar to that shown in the following example: ---- Remember that, whatever you put in the `sources` is merely a Spring `ApplicationContext`. -Normally, anything that already works should work here. There might be some beans you can -remove later and let Spring Boot provide its own defaults for them, but it should be -possible to get something working before you need to do that. +Normally, anything that already works should work here. +There might be some beans you can remove later and let Spring Boot provide its own defaults for them, but it should be possible to get something working before you need to do that. -Static resources can be moved to `/public` (or `/static` or `/resources` or -`/META-INF/resources`) in the classpath root. The same applies to `messages.properties` -(which Spring Boot automatically detects in the root of the classpath). +Static resources can be moved to `/public` (or `/static` or `/resources` or `/META-INF/resources`) in the classpath root. +The same applies to `messages.properties` (which Spring Boot automatically detects in the root of the classpath). -Vanilla usage of Spring `DispatcherServlet` and Spring Security should require no further -changes. If you have other features in your application (for instance, using other -servlets or filters), you may need to add some configuration to your `Application` -context, by replacing those elements from the `web.xml`, as follows: +Vanilla usage of Spring `DispatcherServlet` and Spring Security should require no further changes. +If you have other features in your application (for instance, using other servlets or filters), you may need to add some configuration to your `Application` context, by replacing those elements from the `web.xml`, as follows: -* A `@Bean` of type `Servlet` or `ServletRegistrationBean` installs that bean in the -container as if it were a `` and `` in `web.xml`. -* A `@Bean` of type `Filter` or `FilterRegistrationBean` behaves similarly (as a -`` and ``). -* An `ApplicationContext` in an XML file can be added through an `@ImportResource` in -your `Application`. Alternatively, simple cases where annotation configuration is -heavily used already can be recreated in a few lines as `@Bean` definitions. +* A `@Bean` of type `Servlet` or `ServletRegistrationBean` installs that bean in the container as if it were a `` and `` in `web.xml`. +* A `@Bean` of type `Filter` or `FilterRegistrationBean` behaves similarly (as a `` and ``). +* An `ApplicationContext` in an XML file can be added through an `@ImportResource` in your `Application`. + Alternatively, simple cases where annotation configuration is heavily used already can be recreated in a few lines as `@Bean` definitions. -Once the war file is working, you can make it executable by adding a `main` method to -your `Application`, as shown in the following example: +Once the war file is working, you can make it executable by adding a `main` method to your `Application`, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3230,10 +2674,7 @@ your `Application`, as shown in the following example: [NOTE] ==== -If you intend to start your application as a war or as an executable application, you -need to share the customizations of the builder in a method that is both available to the -`SpringBootServletInitializer` callback and in the `main` method in a class similar to the -following: +If you intend to start your application as a war or as an executable application, you need to share the customizations of the builder in a method that is both available to the `SpringBootServletInitializer` callback and in the `main` method in a class similar to the following: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3264,34 +2705,23 @@ Applications can fall into more than one category: * Applications with a context hierarchy. * Applications without a context hierarchy. -All of these should be amenable to translation, but each might require slightly different -techniques. +All of these should be amenable to translation, but each might require slightly different techniques. -Servlet 3.0+ applications might translate pretty easily if they already use the Spring -Servlet 3.0+ initializer support classes. Normally, all the code from an existing -`WebApplicationInitializer` can be moved into a `SpringBootServletInitializer`. If your -existing application has more than one `ApplicationContext` (for example, if it uses -`AbstractDispatcherServletInitializer`) then you might be able to combine all your context -sources into a single `SpringApplication`. The main complication you might encounter is if -combining does not work and you need to maintain the context hierarchy. See the -<> for -examples. An existing parent context that contains web-specific features usually -needs to be broken up so that all the `ServletContextAware` components are in the child -context. +Servlet 3.0+ applications might translate pretty easily if they already use the Spring Servlet 3.0+ initializer support classes. +Normally, all the code from an existing `WebApplicationInitializer` can be moved into a `SpringBootServletInitializer`. +If your existing application has more than one `ApplicationContext` (for example, if it uses `AbstractDispatcherServletInitializer`) then you might be able to combine all your context sources into a single `SpringApplication`. +The main complication you might encounter is if combining does not work and you need to maintain the context hierarchy. +See the <> for examples. +An existing parent context that contains web-specific features usually needs to be broken up so that all the `ServletContextAware` components are in the child context. -Applications that are not already Spring applications might be convertible to Spring -Boot applications, and the previously mentioned guidance may help. However, you may yet -encounter problems. In that case, we suggest -https://stackoverflow.com/questions/tagged/spring-boot[asking questions on Stack Overflow -with a tag of `spring-boot`]. +Applications that are not already Spring applications might be convertible to Spring Boot applications, and the previously mentioned guidance may help. +However, you may yet encounter problems. In that case, we suggest https://stackoverflow.com/questions/tagged/spring-boot[asking questions on Stack Overflow with a tag of `spring-boot`]. [[howto-weblogic]] === Deploying a WAR to WebLogic -To deploy a Spring Boot application to WebLogic, you must ensure that your servlet -initializer *directly* implements `WebApplicationInitializer` (even if you extend from a -base class that already implements it). +To deploy a Spring Boot application to WebLogic, you must ensure that your servlet initializer *directly* implements `WebApplicationInitializer` (even if you extend from a base class that already implements it). A typical initializer for WebLogic should resemble the following example: @@ -3307,9 +2737,8 @@ A typical initializer for WebLogic should resemble the following example: } ---- -If you use Logback, you also need to tell WebLogic to prefer the packaged version -rather than the version that was pre-installed with the server. You can do so by adding a -`WEB-INF/weblogic.xml` file with the following contents: +If you use Logback, you also need to tell WebLogic to prefer the packaged version rather than the version that was pre-installed with the server. +You can do so by adding a `WEB-INF/weblogic.xml` file with the following contents: [source,xml,indent=0] ---- @@ -3333,10 +2762,9 @@ rather than the version that was pre-installed with the server. You can do so by [[howto-use-jedis-instead-of-lettuce]] === Use Jedis Instead of Lettuce -By default, the Spring Boot starter (`spring-boot-starter-data-redis`) uses -https://github.com/lettuce-io/lettuce-core/[Lettuce]. You need to exclude that -dependency and include the https://github.com/xetorthio/jedis/[Jedis] one instead. Spring -Boot manages these dependencies to help make this process as easy as possible. +By default, the Spring Boot starter (`spring-boot-starter-data-redis`) uses https://github.com/lettuce-io/lettuce-core/[Lettuce]. +You need to exclude that dependency and include the https://github.com/xetorthio/jedis/[Jedis] one instead. +Spring Boot manages these dependencies to help make this process as easy as possible. The following example shows how to do so in Maven: diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/index-docinfo.xml b/spring-boot-project/spring-boot-docs/src/main/asciidoc/index-docinfo.xml index 790b18701d2..a05a95b2694 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/index-docinfo.xml +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/index-docinfo.xml @@ -1,7 +1,7 @@ Spring Boot {spring-boot-version} - 2012-2018 + 2012-2019 diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/production-ready-features.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/production-ready-features.adoc index c99a37509c2..db3fe722c28 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/production-ready-features.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/production-ready-features.adoc @@ -3,25 +3,22 @@ [partintro] -- -Spring Boot includes a number of additional features to help you monitor and manage your -application when you push it to production. You can choose to manage and monitor your -application by using HTTP endpoints or with JMX. Auditing, health, and metrics gathering -can also be automatically applied to your application. +Spring Boot includes a number of additional features to help you monitor and manage your application when you push it to production. +You can choose to manage and monitor your application by using HTTP endpoints or with JMX. +Auditing, health, and metrics gathering can also be automatically applied to your application. -- [[production-ready-enabling]] == Enabling Production-ready Features -The {github-code}/spring-boot-project/spring-boot-actuator[`spring-boot-actuator`] module -provides all of Spring Boot's production-ready features. The simplest way to enable the -features is to add a dependency to the `spring-boot-starter-actuator` '`Starter`'. +The {github-code}/spring-boot-project/spring-boot-actuator[`spring-boot-actuator`] module provides all of Spring Boot's production-ready features. +The simplest way to enable the features is to add a dependency to the `spring-boot-starter-actuator` '`Starter`'. .Definition of Actuator **** -An actuator is a manufacturing term that refers to a mechanical device for moving or -controlling something. Actuators can generate a large amount of motion from a small -change. +An actuator is a manufacturing term that refers to a mechanical device for moving or controlling something. +Actuators can generate a large amount of motion from a small change. **** To add the actuator to a Maven based project, add the following '`Starter`' dependency: @@ -49,17 +46,15 @@ For Gradle, use the following declaration: [[production-ready-endpoints]] == Endpoints -Actuator endpoints let you monitor and interact with your application. Spring Boot -includes a number of built-in endpoints and lets you add your own. For example, the -`health` endpoint provides basic application health information. +Actuator endpoints let you monitor and interact with your application. +Spring Boot includes a number of built-in endpoints and lets you add your own. +For example, the `health` endpoint provides basic application health information. -Each individual endpoint can be <>. This controls whether or not the endpoint is created and its bean exists in -the application context. To be remotely accessible an endpoint also has to be -<>. Most -applications choose HTTP, where the ID of the endpoint along with a prefix of `/actuator` -is mapped to a URL. For example, by default, the `health` endpoint is mapped to -`/actuator/health`. +Each individual endpoint can be <>. +This controls whether or not the endpoint is created and its bean exists in the application context. +To be remotely accessible an endpoint also has to be <>. +Most applications choose HTTP, where the ID of the endpoint along with a prefix of `/actuator` is mapped to a URL. +For example, by default, the `health` endpoint is mapped to `/actuator/health`. The following technology-agnostic endpoints are available: @@ -67,135 +62,125 @@ The following technology-agnostic endpoints are available: |=== | ID | Description | Enabled by default -|`auditevents` -|Exposes audit events information for the current application. -|Yes +| `auditevents` +| Exposes audit events information for the current application. +| Yes -|`beans` -|Displays a complete list of all the Spring beans in your application. -|Yes +| `beans` +| Displays a complete list of all the Spring beans in your application. +| Yes -|`caches` -|Exposes available caches. -|Yes +| `caches` +| Exposes available caches. +| Yes -|`conditions` -|Shows the conditions that were evaluated on configuration and auto-configuration -classes and the reasons why they did or did not match. -|Yes +| `conditions` +| Shows the conditions that were evaluated on configuration and auto-configuration classes and the reasons why they did or did not match. +| Yes -|`configprops` -|Displays a collated list of all `@ConfigurationProperties`. -|Yes +| `configprops` +| Displays a collated list of all `@ConfigurationProperties`. +| Yes -|`env` -|Exposes properties from Spring's `ConfigurableEnvironment`. -|Yes +| `env` +| Exposes properties from Spring's `ConfigurableEnvironment`. +| Yes -|`flyway` -|Shows any Flyway database migrations that have been applied. -|Yes +| `flyway` +| Shows any Flyway database migrations that have been applied. +| Yes -|`health` -|Shows application health information. -|Yes +| `health` +| Shows application health information. +| Yes -|`httptrace` -|Displays HTTP trace information (by default, the last 100 HTTP request-response -exchanges). -|Yes +| `httptrace` +| Displays HTTP trace information (by default, the last 100 HTTP request-response exchanges). +| Yes -|`info` -|Displays arbitrary application info. -|Yes +| `info` +| Displays arbitrary application info. +| Yes -|`integrationgraph` -|Shows the Spring Integration graph. -|Yes +| `integrationgraph` +| Shows the Spring Integration graph. +| Yes -|`loggers` -|Shows and modifies the configuration of loggers in the application. -|Yes +| `loggers` +| Shows and modifies the configuration of loggers in the application. +| Yes -|`liquibase` -|Shows any Liquibase database migrations that have been applied. -|Yes +| `liquibase` +| Shows any Liquibase database migrations that have been applied. +| Yes -|`metrics` -|Shows '`metrics`' information for the current application. -|Yes +| `metrics` +| Shows '`metrics`' information for the current application. +| Yes -|`mappings` -|Displays a collated list of all `@RequestMapping` paths. -|Yes +| `mappings` +| Displays a collated list of all `@RequestMapping` paths. +| Yes -|`scheduledtasks` -|Displays the scheduled tasks in your application. -|Yes +| `scheduledtasks` +| Displays the scheduled tasks in your application. +| Yes -|`sessions` -|Allows retrieval and deletion of user sessions from a Spring Session-backed session -store. Not available when using Spring Session's support for reactive web applications. -|Yes +| `sessions` +| Allows retrieval and deletion of user sessions from a Spring Session-backed session store. + Not available when using Spring Session's support for reactive web applications. +| Yes -|`shutdown` -|Lets the application be gracefully shutdown. -|No - -|`threaddump` -|Performs a thread dump. -|Yes +| `shutdown` +| Lets the application be gracefully shutdown. +| No +| `threaddump` +| Performs a thread dump. +| Yes |=== -If your application is a web application (Spring MVC, Spring WebFlux, or Jersey), you can -use the following additional endpoints: +If your application is a web application (Spring MVC, Spring WebFlux, or Jersey), you can use the following additional endpoints: [cols="2,5,2"] |=== | ID | Description | Enabled by default -|`heapdump` -|Returns an `hprof` heap dump file. -|Yes +| `heapdump` +| Returns an `hprof` heap dump file. +| Yes -|`jolokia` -|Exposes JMX beans over HTTP (when Jolokia is on the classpath, not available for WebFlux). -|Yes +| `jolokia` +| Exposes JMX beans over HTTP (when Jolokia is on the classpath, not available for WebFlux). +| Yes -|`logfile` -|Returns the contents of the logfile (if `logging.file` or `logging.path` properties have -been set). Supports the use of the HTTP `Range` header to retrieve part of the log file's -content. -|Yes - -|`prometheus` -|Exposes metrics in a format that can be scraped by a Prometheus server. -|Yes +| `logfile` +| Returns the contents of the logfile (if `logging.file` or `logging.path` properties have been set). + Supports the use of the HTTP `Range` header to retrieve part of the log file's content. +| Yes +| `prometheus` +| Exposes metrics in a format that can be scraped by a Prometheus server. +| Yes |=== -To learn more about the Actuator's endpoints and their request and response formats, -please refer to the separate API documentation ({spring-boot-actuator-api}/html[HTML] or -{spring-boot-actuator-api}/pdf/spring-boot-actuator-web-api.pdf[PDF]). +To learn more about the Actuator's endpoints and their request and response formats, please refer to the separate API documentation ({spring-boot-actuator-api}/html[HTML] or {spring-boot-actuator-api}/pdf/spring-boot-actuator-web-api.pdf[PDF]). [[production-ready-endpoints-enabling-endpoints]] === Enabling Endpoints -By default, all endpoints except for `shutdown` are enabled. To configure the enablement -of an endpoint, use its `management.endpoint..enabled` property. The following -example enables the `shutdown` endpoint: +By default, all endpoints except for `shutdown` are enabled. +To configure the enablement of an endpoint, use its `management.endpoint..enabled` property. +The following example enables the `shutdown` endpoint: [source,properties,indent=0] ---- management.endpoint.shutdown.enabled=true ---- -If you prefer endpoint enablement to be opt-in rather than opt-out, set the -`management.endpoints.enabled-by-default` property to `false` and use individual endpoint -`enabled` properties to opt back in. The following example enables the `info` endpoint and -disables all other endpoints: +If you prefer endpoint enablement to be opt-in rather than opt-out, set the `management.endpoints.enabled-by-default` property to `false` and use individual endpoint `enabled` properties to opt back in. +The following example enables the `info` endpoint and disables all other endpoints: [source,properties,indent=0] ---- @@ -203,153 +188,145 @@ disables all other endpoints: management.endpoint.info.enabled=true ---- -NOTE: Disabled endpoints are removed entirely from the application context. If you want -to change only the technologies over which an endpoint is exposed, use the -<> -instead. +NOTE: Disabled endpoints are removed entirely from the application context. +If you want to change only the technologies over which an endpoint is exposed, use the <> instead. [[production-ready-endpoints-exposing-endpoints]] === Exposing Endpoints -Since Endpoints may contain sensitive information, careful consideration should be given -about when to expose them. The following table shows the default exposure for the built-in -endpoints: +Since Endpoints may contain sensitive information, careful consideration should be given about when to expose them. +The following table shows the default exposure for the built-in endpoints: [cols="1,1,1"] |=== | ID | JMX | Web -|`auditevents` -|Yes -|No +| `auditevents` +| Yes +| No -|`beans` -|Yes -|No +| `beans` +| Yes +| No -|`caches` -|Yes -|No +| `caches` +| Yes +| No -|`conditions` -|Yes -|No +| `conditions` +| Yes +| No -|`configprops` -|Yes -|No +| `configprops` +| Yes +| No -|`env` -|Yes -|No +| `env` +| Yes +| No -|`flyway` -|Yes -|No +| `flyway` +| Yes +| No -|`health` -|Yes -|Yes +| `health` +| Yes +| Yes -|`heapdump` -|N/A -|No +| `heapdump` +| N/A +| No -|`httptrace` -|Yes -|No +| `httptrace` +| Yes +| No -|`info` -|Yes -|Yes +| `info` +| Yes +| Yes -|`integrationgraph` -|Yes -|No +| `integrationgraph` +| Yes +| No -|`jolokia` -|N/A -|No +| `jolokia` +| N/A +| No -|`logfile` -|N/A -|No +| `logfile` +| N/A +| No -|`loggers` -|Yes -|No +| `loggers` +| Yes +| No -|`liquibase` -|Yes -|No +| `liquibase` +| Yes +| No -|`metrics` -|Yes -|No +| `metrics` +| Yes +| No -|`mappings` -|Yes -|No +| `mappings` +| Yes +| No -|`prometheus` -|N/A -|No +| `prometheus` +| N/A +| No -|`scheduledtasks` -|Yes -|No +| `scheduledtasks` +| Yes +| No -|`sessions` -|Yes -|No +| `sessions` +| Yes +| No -|`shutdown` -|Yes -|No - -|`threaddump` -|Yes -|No +| `shutdown` +| Yes +| No +| `threaddump` +| Yes +| No |=== -To change which endpoints are exposed, use the following technology-specific `include` and -`exclude` properties: +To change which endpoints are exposed, use the following technology-specific `include` and `exclude` properties: [cols="3,1"] |=== -|Property | Default +| Property | Default -|`management.endpoints.jmx.exposure.exclude` +| `management.endpoints.jmx.exposure.exclude` | -|`management.endpoints.jmx.exposure.include` +| `management.endpoints.jmx.exposure.include` | `*` -|`management.endpoints.web.exposure.exclude` +| `management.endpoints.web.exposure.exclude` | |`management.endpoints.web.exposure.include` | `info, health` - |=== -The `include` property lists the IDs of the endpoints that are exposed. The `exclude` -property lists the IDs of the endpoints that should not be exposed. The `exclude` -property takes precedence over the `include` property. Both `include` and `exclude` -properties can be configured with a list of endpoint IDs. +The `include` property lists the IDs of the endpoints that are exposed. +The `exclude` property lists the IDs of the endpoints that should not be exposed. +The `exclude` property takes precedence over the `include` property. +Both `include` and `exclude` properties can be configured with a list of endpoint IDs. -For example, to stop exposing all endpoints over JMX and only expose the `health` and -`info` endpoints, use the following property: +For example, to stop exposing all endpoints over JMX and only expose the `health` and `info` endpoints, use the following property: [source,properties,indent=0] ---- management.endpoints.jmx.exposure.include=health,info ---- -`*` can be used to select all endpoints. For example, to expose everything over HTTP -except the `env` and `beans` endpoints, use the following properties: +`*` can be used to select all endpoints. For example, to expose everything over HTTP except the `env` and `beans` endpoints, use the following properties: [source,properties,indent=0] ---- @@ -359,8 +336,7 @@ except the `env` and `beans` endpoints, use the following properties: [NOTE] ==== -`*` has a special meaning in YAML, so be sure to add quotes if you want to include (or -exclude) all endpoints, as shown in the following example: +`*` has a special meaning in YAML, so be sure to add quotes if you want to include (or exclude) all endpoints, as shown in the following example: [source,yaml,indent=0] ---- @@ -372,22 +348,17 @@ exclude) all endpoints, as shown in the following example: ---- ==== -NOTE: If your application is exposed publicly, we strongly recommend that you also -<>. +NOTE: If your application is exposed publicly, we strongly recommend that you also <>. -TIP: If you want to implement your own strategy for when endpoints are exposed, you can -register an `EndpointFilter` bean. +TIP: If you want to implement your own strategy for when endpoints are exposed, you can register an `EndpointFilter` bean. [[production-ready-endpoints-security]] === Securing HTTP Endpoints -You should take care to secure HTTP endpoints in the same way that you would any other -sensitive URL. If Spring Security is present, endpoints are secured by default using -Spring Security’s content-negotiation strategy. If you wish to configure custom security -for HTTP endpoints, for example, only allow users with a certain role to access them, -Spring Boot provides some convenient `RequestMatcher` objects that can be used in -combination with Spring Security. +You should take care to secure HTTP endpoints in the same way that you would any other sensitive URL. +If Spring Security is present, endpoints are secured by default using Spring Security’s content-negotiation strategy. +If you wish to configure custom security for HTTP endpoints, for example, only allow users with a certain role to access them, Spring Boot provides some convenient `RequestMatcher` objects that can be used in combination with Spring Security. A typical Spring Security configuration might look something like the following example: @@ -407,15 +378,12 @@ A typical Spring Security configuration might look something like the following } ---- -The preceding example uses `EndpointRequest.toAnyEndpoint()` to match a request to any -endpoint and then ensures that all have the `ENDPOINT_ADMIN` role. Several other matcher -methods are also available on `EndpointRequest`. See the API documentation -({spring-boot-actuator-api}/html[HTML] or -{spring-boot-actuator-api}/pdf/spring-boot-actuator-web-api.pdf[PDF]) for details. +The preceding example uses `EndpointRequest.toAnyEndpoint()` to match a request to any endpoint and then ensures that all have the `ENDPOINT_ADMIN` role. +Several other matcher methods are also available on `EndpointRequest`. +See the API documentation ({spring-boot-actuator-api}/html[HTML] or {spring-boot-actuator-api}/pdf/spring-boot-actuator-web-api.pdf[PDF]) for details. -If you deploy applications behind a firewall, you may prefer that all your actuator -endpoints can be accessed without requiring authentication. You can do so by changing the -`management.endpoints.web.exposure.include` property, as follows: +If you deploy applications behind a firewall, you may prefer that all your actuator endpoints can be accessed without requiring authentication. +You can do so by changing the `management.endpoints.web.exposure.include` property, as follows: .application.properties [source,properties,indent=0] @@ -423,9 +391,7 @@ endpoints can be accessed without requiring authentication. You can do so by cha management.endpoints.web.exposure.include=* ---- -Additionally, if Spring Security is present, you would need to add custom security -configuration that allows unauthenticated access to the endpoints as shown in the -following example: +Additionally, if Spring Security is present, you would need to add custom security configuration that allows unauthenticated access to the endpoints as shown in the following example: [source,java,indent=0] ---- @@ -445,10 +411,9 @@ following example: [[production-ready-endpoints-caching]] === Configuring Endpoints -Endpoints automatically cache responses to read operations that do not take any -parameters. To configure the amount of time for which an endpoint will cache a response, -use its `cache.time-to-live` property. The following example sets the time-to-live of -the `beans` endpoint's cache to 10 seconds: +Endpoints automatically cache responses to read operations that do not take any parameters. +To configure the amount of time for which an endpoint will cache a response, use its `cache.time-to-live` property. +The following example sets the time-to-live of the `beans` endpoint's cache to 10 seconds: .application.properties [source,properties,indent=0] @@ -456,37 +421,29 @@ the `beans` endpoint's cache to 10 seconds: management.endpoint.beans.cache.time-to-live=10s ---- -NOTE: The prefix `management.endpoint.` is used to uniquely identify the -endpoint that is being configured. +NOTE: The prefix `management.endpoint.` is used to uniquely identify the endpoint that is being configured. -NOTE: When making an authenticated HTTP request, the `Principal` is considered as input to -the endpoint and, therefore, the response will not be cached. +NOTE: When making an authenticated HTTP request, the `Principal` is considered as input to the endpoint and, therefore, the response will not be cached. [[production-ready-endpoints-hypermedia]] === Hypermedia for Actuator Web Endpoints -A "`discovery page`" is added with links to all the endpoints. The "`discovery page`" is -available on `/actuator` by default. +A "`discovery page`" is added with links to all the endpoints. The "`discovery page`" is available on `/actuator` by default. -When a custom management context path is configured, the "`discovery page`" automatically -moves from `/actuator` to the root of the management context. For example, if the -management context path is `/management`, then the discovery page is available from -`/management`. When the management context path is set to `/`, the discovery page is -disabled to prevent the possibility of a clash with other mappings. +When a custom management context path is configured, the "`discovery page`" automatically moves from `/actuator` to the root of the management context. +For example, if the management context path is `/management`, then the discovery page is available from `/management`. +When the management context path is set to `/`, the discovery page is disabled to prevent the possibility of a clash with other mappings. [[production-ready-endpoints-cors]] === CORS Support -https://en.wikipedia.org/wiki/Cross-origin_resource_sharing[Cross-origin resource sharing] -(CORS) is a https://www.w3.org/TR/cors/[W3C specification] that lets you specify in a -flexible way what kind of cross-domain requests are authorized. If you use Spring MVC or -Spring WebFlux, Actuator's web endpoints can be configured to support such scenarios. +https://en.wikipedia.org/wiki/Cross-origin_resource_sharing[Cross-origin resource sharing] (CORS) is a https://www.w3.org/TR/cors/[W3C specification] that lets you specify in a flexible way what kind of cross-domain requests are authorized. +If you use Spring MVC or Spring WebFlux, Actuator's web endpoints can be configured to support such scenarios. -CORS support is disabled by default and is only enabled once the -`management.endpoints.web.cors.allowed-origins` property has been set. The following -configuration permits `GET` and `POST` calls from the `example.com` domain: +CORS support is disabled by default and is only enabled once the `management.endpoints.web.cors.allowed-origins` property has been set. +The following configuration permits `GET` and `POST` calls from the `example.com` domain: [source,properties,indent=0] ---- @@ -494,40 +451,33 @@ configuration permits `GET` and `POST` calls from the `example.com` domain: management.endpoints.web.cors.allowed-methods=GET,POST ---- -TIP: See -{sc-spring-boot-actuator-autoconfigure}/endpoint/web/CorsEndpointProperties.{sc-ext}[CorsEndpointProperties] -for a complete list of options. +TIP: See {sc-spring-boot-actuator-autoconfigure}/endpoint/web/CorsEndpointProperties.{sc-ext}[CorsEndpointProperties] for a complete list of options. [[production-ready-endpoints-custom]] === Implementing Custom Endpoints -If you add a `@Bean` annotated with `@Endpoint`, any methods annotated with -`@ReadOperation`, `@WriteOperation`, or `@DeleteOperation` are automatically exposed over -JMX and, in a web application, over HTTP as well. Endpoints can be exposed over HTTP using -Jersey, Spring MVC, or Spring WebFlux. +If you add a `@Bean` annotated with `@Endpoint`, any methods annotated with `@ReadOperation`, `@WriteOperation`, or `@DeleteOperation` are automatically exposed over JMX and, in a web application, over HTTP as well. +Endpoints can be exposed over HTTP using Jersey, Spring MVC, or Spring WebFlux. -You can also write technology-specific endpoints by using `@JmxEndpoint` or -`@WebEndpoint`. These endpoints are restricted to their respective technologies. For -example, `@WebEndpoint` is exposed only over HTTP and not over JMX. +You can also write technology-specific endpoints by using `@JmxEndpoint` or `@WebEndpoint`. +These endpoints are restricted to their respective technologies. +For example, `@WebEndpoint` is exposed only over HTTP and not over JMX. -You can write technology-specific extensions by using `@EndpointWebExtension` and -`@EndpointJmxExtension`. These annotations let you provide technology-specific operations -to augment an existing endpoint. +You can write technology-specific extensions by using `@EndpointWebExtension` and `@EndpointJmxExtension`. +These annotations let you provide technology-specific operations to augment an existing endpoint. -Finally, if you need access to web-framework-specific functionality, you can implement -Servlet or Spring `@Controller` and `@RestController` endpoints at the cost of them not -being available over JMX or when using a different web framework. +Finally, if you need access to web-framework-specific functionality, you can implement Servlet or Spring `@Controller` and `@RestController` endpoints at the cost of them not being available over JMX or when using a different web framework. [[production-ready-endpoints-custom-input]] ==== Receiving Input -Operations on an endpoint receive input via their parameters. When exposed via the web, -the values for these parameters are taken from the URL's query parameters and from the -JSON request body. When exposed via JMX, the parameters are mapped to the parameters of -the MBean's operations. Parameters are required by default. They can be made optional -by annotating them with `@org.springframework.lang.Nullable`. +Operations on an endpoint receive input via their parameters. +When exposed via the web, the values for these parameters are taken from the URL's query parameters and from the JSON request body. +When exposed via JMX, the parameters are mapped to the parameters of the MBean's operations. +Parameters are required by default. +They can be made optional by annotating them with `@org.springframework.lang.Nullable`. Each root property in the JSON request body can be mapped to a parameter of the endpoint. Consider the following JSON request body: @@ -540,123 +490,105 @@ Consider the following JSON request body: } ---- -This can be used to invoke a write operation that takes `String name` and `int counter` -parameters. +This can be used to invoke a write operation that takes `String name` and `int counter` parameters. -TIP: Because endpoints are technology agnostic, only simple types can be specified in the -method signature. In particular declaring a single parameter with a custom type defining a -`name` and `counter` properties is not supported. +TIP: Because endpoints are technology agnostic, only simple types can be specified in the method signature. +In particular declaring a single parameter with a custom type defining a `name` and `counter` properties is not supported. -NOTE: To allow the input to be mapped to the operation method's parameters, Java code -implementing an endpoint should be compiled with `-parameters`, and Kotlin code -implementing an endpoint should be compiled with `-java-parameters`. This will happen -automatically if you are using Spring Boot's Gradle plugin or if you are using Maven and -`spring-boot-starter-parent`. +NOTE: To allow the input to be mapped to the operation method's parameters, Java code implementing an endpoint should be compiled with `-parameters`, and Kotlin code implementing an endpoint should be compiled with `-java-parameters`. +This will happen automatically if you are using Spring Boot's Gradle plugin or if you are using Maven and `spring-boot-starter-parent`. [[production-ready-endpoints-custom-input-conversion]] ===== Input type conversion -The parameters passed to endpoint operation methods are, if necessary, automatically -converted to the required type. Before calling an operation method, the input received via -JMX or an HTTP request is converted to the required types using an instance of -`ApplicationConversionService`. +The parameters passed to endpoint operation methods are, if necessary, automatically converted to the required type. +Before calling an operation method, the input received via JMX or an HTTP request is converted to the required types using an instance of `ApplicationConversionService`. [[production-ready-endpoints-custom-web]] ==== Custom Web Endpoints -Operations on an `@Endpoint`, `@WebEndpoint`, or `@EndpointWebExtension` are automatically -exposed over HTTP using Jersey, Spring MVC, or Spring WebFlux. +Operations on an `@Endpoint`, `@WebEndpoint`, or `@EndpointWebExtension` are automatically exposed over HTTP using Jersey, Spring MVC, or Spring WebFlux. [[production-ready-endpoints-custom-web-predicate]] ===== Web Endpoint Request Predicates -A request predicate is automatically generated for each operation on a web-exposed -endpoint. +A request predicate is automatically generated for each operation on a web-exposed endpoint. [[production-ready-endpoints-custom-web-predicate-path]] ===== Path -The path of the predicate is determined by the ID of the endpoint and the base path of -web-exposed endpoints. The default base path is `/actuator`. For example, an endpoint with -the ID `sessions` will use `/actuator/sessions` as its path in the predicate. +The path of the predicate is determined by the ID of the endpoint and the base path of web-exposed endpoints. +The default base path is `/actuator`. +For example, an endpoint with the ID `sessions` will use `/actuator/sessions` as its path in the predicate. -The path can be further customized by annotating one or more parameters of the operation -method with `@Selector`. Such a parameter is added to the path predicate as a path -variable. The variable's value is passed into the operation method when the endpoint -operation is invoked. +The path can be further customized by annotating one or more parameters of the operation method with `@Selector`. +Such a parameter is added to the path predicate as a path variable. +The variable's value is passed into the operation method when the endpoint operation is invoked. [[production-ready-endpoints-custom-web-predicate-http-method]] ===== HTTP method - -The HTTP method of the predicate is determined by the operation type, as shown in -the following table: +The HTTP method of the predicate is determined by the operation type, as shown in the following table: [cols="3, 1"] |=== -|Operation |HTTP method +| Operation | HTTP method -|`@ReadOperation` -|`GET` +| `@ReadOperation` +| `GET` -|`@WriteOperation` -|`POST` +| `@WriteOperation` +| `POST` -|`@DeleteOperation` -|`DELETE` +| `@DeleteOperation` +| `DELETE` |=== [[production-ready-endpoints-custom-web-predicate-consumes]] ===== Consumes -For a `@WriteOperation` (HTTP `POST`) that uses the request body, the consumes clause of -the predicate is `application/vnd.spring-boot.actuator.v2+json, application/json`. For -all other operations the consumes clause is empty. +For a `@WriteOperation` (HTTP `POST`) that uses the request body, the consumes clause of the predicate is `application/vnd.spring-boot.actuator.v2+json, application/json`. +For all other operations the consumes clause is empty. [[production-ready-endpoints-custom-web-predicate-produces]] ===== Produces -The produces clause of the predicate can be determined by the `produces` attribute of the -`@DeleteOperation`, `@ReadOperation`, and `@WriteOperation` annotations. The attribute is -optional. If it is not used, the produces clause is determined automatically. +The produces clause of the predicate can be determined by the `produces` attribute of the `@DeleteOperation`, `@ReadOperation`, and `@WriteOperation` annotations. +The attribute is optional. +If it is not used, the produces clause is determined automatically. -If the operation method returns `void` or `Void` the produces clause is empty. If the -operation method returns a `org.springframework.core.io.Resource`, the produces clause is -`application/octet-stream`. For all other operations the produces clause is -`application/vnd.spring-boot.actuator.v2+json, application/json`. +If the operation method returns `void` or `Void` the produces clause is empty. +If the operation method returns a `org.springframework.core.io.Resource`, the produces clause is `application/octet-stream`. +For all other operations the produces clause is `application/vnd.spring-boot.actuator.v2+json, application/json`. [[production-ready-endpoints-custom-web-response-status]] ===== Web Endpoint Response Status -The default response status for an endpoint operation depends on the operation type (read, -write, or delete) and what, if anything, the operation returns. +The default response status for an endpoint operation depends on the operation type (read, write, or delete) and what, if anything, the operation returns. -A `@ReadOperation` returns a value, the response status will be 200 (OK). If it does not -return a value, the response status will be 404 (Not Found). +A `@ReadOperation` returns a value, the response status will be 200 (OK). +If it does not return a value, the response status will be 404 (Not Found). -If a `@WriteOperation` or `@DeleteOperation` returns a value, the response status will be -200 (OK). If it does not return a value the response status will be 204 (No Content). +If a `@WriteOperation` or `@DeleteOperation` returns a value, the response status will be 200 (OK). +If it does not return a value the response status will be 204 (No Content). -If an operation is invoked without a required parameter, or with a parameter that cannot -be converted to the required type, the operation method will not be called and the -response status will be 400 (Bad Request). +If an operation is invoked without a required parameter, or with a parameter that cannot be converted to the required type, the operation method will not be called and the response status will be 400 (Bad Request). [[production-ready-endpoints-custom-web-range-requests]] ===== Web Endpoint Range Requests -An HTTP range request can be used to request part of an HTTP resource. When using Spring -MVC or Spring Web Flux, operations that return a `org.springframework.core.io.Resource` -automatically support range requests. +An HTTP range request can be used to request part of an HTTP resource. +When using Spring MVC or Spring Web Flux, operations that return a `org.springframework.core.io.Resource` automatically support range requests. NOTE: Range requests are not supported when using Jersey. @@ -664,83 +596,64 @@ NOTE: Range requests are not supported when using Jersey. [[production-ready-endpoints-custom-web-security]] ===== Web Endpoint Security -An operation on a web endpoint or a web-specific endpoint extension can receive the -current `java.security.Principal` or -`org.springframework.boot.actuate.endpoint.SecurityContext` as a method parameter. The -former is typically used in conjunction with `@Nullable` to provide different behaviour -for authenticated and unauthenticated users. The latter is typically used to perform -authorization checks using its `isUserInRole(String)` method. +An operation on a web endpoint or a web-specific endpoint extension can receive the current `java.security.Principal` or `org.springframework.boot.actuate.endpoint.SecurityContext` as a method parameter. +The former is typically used in conjunction with `@Nullable` to provide different behavior for authenticated and unauthenticated users. +The latter is typically used to perform authorization checks using its `isUserInRole(String)` method. [[production-ready-endpoints-custom-servlet]] ==== Servlet endpoints -A `Servlet` can be exposed as an endpoint by implementing a class annotated with -`@ServletEndpoint` that also implements `Supplier`. Servlet endpoints -provide deeper integration with the Servlet container but at the expense of portability. -They are intended to be used to expose an existing `Servlet` as an endpoint. For new -endpoints, the `@Endpoint` and `@WebEndpoint` annotations should be preferred whenever -possible. +A `Servlet` can be exposed as an endpoint by implementing a class annotated with `@ServletEndpoint` that also implements `Supplier`. +Servlet endpoints provide deeper integration with the Servlet container but at the expense of portability. +They are intended to be used to expose an existing `Servlet` as an endpoint. +For new endpoints, the `@Endpoint` and `@WebEndpoint` annotations should be preferred whenever possible. [[production-ready-endpoints-custom-controller]] ==== Controller endpoints -`@ControllerEndpoint` and `@RestControllerEndpoint` can be used to implement an endpoint -that is only exposed by Spring MVC or Spring WebFlux. Methods are mapped using the -standard annotations for Spring MVC and Spring WebFlux such as `@RequestMapping` -and `@GetMapping`, with the endpoint's ID being used as a prefix for the path. Controller -endpoints provide deeper integration with Spring's web frameworks but at the expense of -portability. The `@Endpoint` and `@WebEndpoint` annotations should be preferred whenever -possible. +`@ControllerEndpoint` and `@RestControllerEndpoint` can be used to implement an endpoint that is only exposed by Spring MVC or Spring WebFlux. +Methods are mapped using the standard annotations for Spring MVC and Spring WebFlux such as `@RequestMapping` and `@GetMapping`, with the endpoint's ID being used as a prefix for the path. +Controller endpoints provide deeper integration with Spring's web frameworks but at the expense of portability. +The `@Endpoint` and `@WebEndpoint` annotations should be preferred whenever possible. [[production-ready-health]] === Health Information -You can use health information to check the status of your running application. It is -often used by monitoring software to alert someone when a production system goes down. -The information exposed by the `health` endpoint depends on the -`management.endpoint.health.show-details` property which can be configured with one of the -following values: +You can use health information to check the status of your running application. +It is often used by monitoring software to alert someone when a production system goes down. +The information exposed by the `health` endpoint depends on the `management.endpoint.health.show-details` property which can be configured with one of the following values: [cols="1, 3"] |=== -|Name |Description +| Name | Description -|`never` -|Details are never shown. +| `never` +| Details are never shown. -|`when-authorized` -|Details are only shown to authorized users. Authorized roles can be configured using -`management.endpoint.health.roles`. +| `when-authorized` +| Details are only shown to authorized users. + Authorized roles can be configured using `management.endpoint.health.roles`. -|`always` -|Details are shown to all users. +| `always` +| Details are shown to all users. |=== -The default value is `never`. A user is considered to be authorized when they -are in one or more of the endpoint's roles. If the endpoint has no configured roles -(the default) all authenticated users are considered to be authorized. The roles can -be configured using the `management.endpoint.health.roles` property. +The default value is `never`. A user is considered to be authorized when they are in one or more of the endpoint's roles. +If the endpoint has no configured roles (the default) all authenticated users are considered to be authorized. +The roles can be configured using the `management.endpoint.health.roles` property. -NOTE: If you have secured your application and wish to use `always`, your security -configuration must permit access to the health endpoint for both authenticated and -unauthenticated users. +NOTE: If you have secured your application and wish to use `always`, your security configuration must permit access to the health endpoint for both authenticated and unauthenticated users. -Health information is collected from the content of a -{sc-spring-boot-actuator}/health/HealthIndicatorRegistry.{sc-ext}[ -`HealthIndicatorRegistry`] (by default all -{sc-spring-boot-actuator}/health/HealthIndicator.{sc-ext}[`HealthIndicator`] instances -defined in your `ApplicationContext`. Spring Boot includes a number of auto-configured -`HealthIndicators` and you can also write your own. By default, the final system state is -derived by the `HealthAggregator` which sorts the statuses from each `HealthIndicator` -based on an ordered list of statuses. The first status in the sorted list is used as the -overall health status. If no `HealthIndicator` returns a status that is known to the -`HealthAggregator`, an `UNKNOWN` status is used. +Health information is collected from the content of a {sc-spring-boot-actuator}/health/HealthIndicatorRegistry.{sc-ext}[`HealthIndicatorRegistry`] (by default all {sc-spring-boot-actuator}/health/HealthIndicator.{sc-ext}[`HealthIndicator`] instances defined in your `ApplicationContext`. +Spring Boot includes a number of auto-configured `HealthIndicators` and you can also write your own. +By default, the final system state is derived by the `HealthAggregator` which sorts the statuses from each `HealthIndicator` based on an ordered list of statuses. +The first status in the sorted list is used as the overall health status. +If no `HealthIndicator` returns a status that is known to the `HealthAggregator`, an `UNKNOWN` status is used. -TIP: The `HealthIndicatorRegistry` can be used to register and unregister health -indicators at runtime. +TIP: The `HealthIndicatorRegistry` can be used to register and unregister health indicators at runtime. @@ -749,60 +662,56 @@ The following `HealthIndicators` are auto-configured by Spring Boot when appropr [cols="4,6"] |=== -|Name |Description +| Name | Description -|{sc-spring-boot-actuator}/cassandra/CassandraHealthIndicator.{sc-ext}[`CassandraHealthIndicator`] -|Checks that a Cassandra database is up. +| {sc-spring-boot-actuator}/cassandra/CassandraHealthIndicator.{sc-ext}[`CassandraHealthIndicator`] +| Checks that a Cassandra database is up. -|{sc-spring-boot-actuator}/couchbase/CouchbaseHealthIndicator.{sc-ext}[`CouchbaseHealthIndicator`] -|Checks that a Couchbase cluster is up. +| {sc-spring-boot-actuator}/couchbase/CouchbaseHealthIndicator.{sc-ext}[`CouchbaseHealthIndicator`] +| Checks that a Couchbase cluster is up. -|{sc-spring-boot-actuator}/system/DiskSpaceHealthIndicator.{sc-ext}[`DiskSpaceHealthIndicator`] -|Checks for low disk space. +| {sc-spring-boot-actuator}/system/DiskSpaceHealthIndicator.{sc-ext}[`DiskSpaceHealthIndicator`] +| Checks for low disk space. -|{sc-spring-boot-actuator}/jdbc/DataSourceHealthIndicator.{sc-ext}[`DataSourceHealthIndicator`] -|Checks that a connection to `DataSource` can be obtained. +| {sc-spring-boot-actuator}/jdbc/DataSourceHealthIndicator.{sc-ext}[`DataSourceHealthIndicator`] +| Checks that a connection to `DataSource` can be obtained. -|{sc-spring-boot-actuator}/elasticsearch/ElasticsearchHealthIndicator.{sc-ext}[`ElasticsearchHealthIndicator`] -|Checks that an Elasticsearch cluster is up. +| {sc-spring-boot-actuator}/elasticsearch/ElasticsearchHealthIndicator.{sc-ext}[`ElasticsearchHealthIndicator`] +| Checks that an Elasticsearch cluster is up. -|{sc-spring-boot-actuator}/influx/InfluxDbHealthIndicator.{sc-ext}[`InfluxDbHealthIndicator`] -|Checks that an InfluxDB server is up. +| {sc-spring-boot-actuator}/influx/InfluxDbHealthIndicator.{sc-ext}[`InfluxDbHealthIndicator`] +| Checks that an InfluxDB server is up. -|{sc-spring-boot-actuator}/jms/JmsHealthIndicator.{sc-ext}[`JmsHealthIndicator`] -|Checks that a JMS broker is up. +| {sc-spring-boot-actuator}/jms/JmsHealthIndicator.{sc-ext}[`JmsHealthIndicator`] +| Checks that a JMS broker is up. -|{sc-spring-boot-actuator}/mail/MailHealthIndicator.{sc-ext}[`MailHealthIndicator`] -|Checks that a mail server is up. +| {sc-spring-boot-actuator}/mail/MailHealthIndicator.{sc-ext}[`MailHealthIndicator`] +| Checks that a mail server is up. -|{sc-spring-boot-actuator}/mongo/MongoHealthIndicator.{sc-ext}[`MongoHealthIndicator`] -|Checks that a Mongo database is up. +| {sc-spring-boot-actuator}/mongo/MongoHealthIndicator.{sc-ext}[`MongoHealthIndicator`] +| Checks that a Mongo database is up. -|{sc-spring-boot-actuator}/neo4j/Neo4jHealthIndicator.{sc-ext}[`Neo4jHealthIndicator`] -|Checks that a Neo4j server is up. +| {sc-spring-boot-actuator}/neo4j/Neo4jHealthIndicator.{sc-ext}[`Neo4jHealthIndicator`] +| Checks that a Neo4j server is up. -|{sc-spring-boot-actuator}/amqp/RabbitHealthIndicator.{sc-ext}[`RabbitHealthIndicator`] -|Checks that a Rabbit server is up. +| {sc-spring-boot-actuator}/amqp/RabbitHealthIndicator.{sc-ext}[`RabbitHealthIndicator`] +| Checks that a Rabbit server is up. -|{sc-spring-boot-actuator}/redis/RedisHealthIndicator.{sc-ext}[`RedisHealthIndicator`] -|Checks that a Redis server is up. - -|{sc-spring-boot-actuator}/solr/SolrHealthIndicator.{sc-ext}[`SolrHealthIndicator`] -|Checks that a Solr server is up. +| {sc-spring-boot-actuator}/redis/RedisHealthIndicator.{sc-ext}[`RedisHealthIndicator`] +| Checks that a Redis server is up. +| {sc-spring-boot-actuator}/solr/SolrHealthIndicator.{sc-ext}[`SolrHealthIndicator`] +| Checks that a Solr server is up. |=== -TIP: You can disable them all by setting the `management.health.defaults.enabled` -property. +TIP: You can disable them all by setting the `management.health.defaults.enabled` property. ==== Writing Custom HealthIndicators -To provide custom health information, you can register Spring beans that implement the -{sc-spring-boot-actuator}/health/HealthIndicator.{sc-ext}[`HealthIndicator`] interface. -You need to provide an implementation of the `health()` method and return a `Health` -response. The `Health` response should include a status and can optionally include -additional details to be displayed. The following code shows a sample `HealthIndicator` -implementation: +To provide custom health information, you can register Spring beans that implement the {sc-spring-boot-actuator}/health/HealthIndicator.{sc-ext}[`HealthIndicator`] interface. +You need to provide an implementation of the `health()` method and return a `Health` response. +The `Health` response should include a status and can optionally include additional details to be displayed. +The following code shows a sample `HealthIndicator` implementation: [source,java,indent=0] ---- @@ -825,31 +734,22 @@ implementation: } ---- -NOTE: The identifier for a given `HealthIndicator` is the name of the bean without the -`HealthIndicator` suffix, if it exists. In the preceding example, the health information -is available in an entry named `my`. +NOTE: The identifier for a given `HealthIndicator` is the name of the bean without the `HealthIndicator` suffix, if it exists. +In the preceding example, the health information is available in an entry named `my`. -In addition to Spring Boot's predefined -{sc-spring-boot-actuator}/health/Status.{sc-ext}[`Status`] types, it is also possible for -`Health` to return a custom `Status` that represents a new system state. In such cases, a -custom implementation of the -{sc-spring-boot-actuator}/health/HealthAggregator.{sc-ext}[`HealthAggregator`] interface -also needs to be provided, or the default implementation has to be configured by using -the `management.health.status.order` configuration property. +In addition to Spring Boot's predefined {sc-spring-boot-actuator}/health/Status.{sc-ext}[`Status`] types, it is also possible for `Health` to return a custom `Status` that represents a new system state. +In such cases, a custom implementation of the {sc-spring-boot-actuator}/health/HealthAggregator.{sc-ext}[`HealthAggregator`] interface also needs to be provided, or the default implementation has to be configured by using the `management.health.status.order` configuration property. -For example, assume a new `Status` with code `FATAL` is being used in one of your -`HealthIndicator` implementations. To configure the severity order, add the following -property to your application properties: +For example, assume a new `Status` with code `FATAL` is being used in one of your `HealthIndicator` implementations. +To configure the severity order, add the following property to your application properties: [source,properties,indent=0] ---- management.health.status.order=FATAL, DOWN, OUT_OF_SERVICE, UNKNOWN, UP ---- -The HTTP status code in the response reflects the overall health status (for example, -`UP` maps to 200, while `OUT_OF_SERVICE` and `DOWN` map to 503). You might also want to -register custom status mappings if you access the health endpoint over HTTP. For example, -the following property maps `FATAL` to 503 (service unavailable): +The HTTP status code in the response reflects the overall health status (for example, `UP` maps to 200, while `OUT_OF_SERVICE` and `DOWN` map to 503). +You might also want to register custom status mappings if you access the health endpoint over HTTP. For example, the following property maps `FATAL` to 503 (service unavailable): [source,properties,indent=0] ---- @@ -862,43 +762,33 @@ The following table shows the default status mappings for the built-in statuses: [cols="1,3"] |=== -|Status |Mapping +| Status | Mapping -|DOWN -|SERVICE_UNAVAILABLE (503) +| DOWN +| SERVICE_UNAVAILABLE (503) -|OUT_OF_SERVICE -|SERVICE_UNAVAILABLE (503) +| OUT_OF_SERVICE +| SERVICE_UNAVAILABLE (503) -|UP -|No mapping by default, so http status is 200 +| UP +| No mapping by default, so http status is 200 -|UNKNOWN -|No mapping by default, so http status is 200 +| UNKNOWN +| No mapping by default, so http status is 200 |=== [[reactive-health-indicators]] ==== Reactive Health Indicators -For reactive applications, such as those using Spring WebFlux, `ReactiveHealthIndicator` -provides a non-blocking contract for getting application health. Similar to a traditional -`HealthIndicator`, health information is collected from the content of a -{sc-spring-boot-actuator}/health/ReactiveHealthIndicatorRegistry.{sc-ext}[ -`ReactiveHealthIndicatorRegistry`] (by default all -{sc-spring-boot-actuator}/health/HealthIndicator.{sc-ext}[`HealthIndicator`] and -{sc-spring-boot-actuator}/health/ReactiveHealthIndicator.{sc-ext}[ -`ReactiveHealthIndicator`] instances defined in your `ApplicationContext`. Regular -`HealthIndicator` that do not check against a reactive API are executed on the elastic -scheduler. +For reactive applications, such as those using Spring WebFlux, `ReactiveHealthIndicator` provides a non-blocking contract for getting application health. +Similar to a traditional `HealthIndicator`, health information is collected from the content of a {sc-spring-boot-actuator}/health/ReactiveHealthIndicatorRegistry.{sc-ext}[`ReactiveHealthIndicatorRegistry`] (by default all {sc-spring-boot-actuator}/health/HealthIndicator.{sc-ext}[`HealthIndicator`] and {sc-spring-boot-actuator}/health/ReactiveHealthIndicator.{sc-ext}[`ReactiveHealthIndicator`] instances defined in your `ApplicationContext`. +Regular `HealthIndicator` that do not check against a reactive API are executed on the elastic scheduler. -TIP: In a reactive application, The `ReactiveHealthIndicatorRegistry` can be used to -register and unregister health indicators at runtime. +TIP: In a reactive application, The `ReactiveHealthIndicatorRegistry` can be used to register and unregister health indicators at runtime. -To provide custom health information from a reactive API, you can register Spring beans -that implement the -{sc-spring-boot-actuator}/health/ReactiveHealthIndicator.{sc-ext}[`ReactiveHealthIndicator`] -interface. The following code shows a sample `ReactiveHealthIndicator` implementation: +To provide custom health information from a reactive API, you can register Spring beans that implement the {sc-spring-boot-actuator}/health/ReactiveHealthIndicator.{sc-ext}[`ReactiveHealthIndicator`] interface. +The following code shows a sample `ReactiveHealthIndicator` implementation: [source,java,indent=0] ---- @@ -914,71 +804,68 @@ interface. The following code shows a sample `ReactiveHealthIndicator` implement } ---- -TIP: To handle the error automatically, consider extending from -`AbstractReactiveHealthIndicator`. +TIP: To handle the error automatically, consider extending from `AbstractReactiveHealthIndicator`. ==== Auto-configured ReactiveHealthIndicators -The following `ReactiveHealthIndicators` are auto-configured by Spring Boot when -appropriate: +The following `ReactiveHealthIndicators` are auto-configured by Spring Boot when appropriate: [cols="1,4"] |=== -|Name |Description +| Name | Description -|{sc-spring-boot-actuator}/cassandra/CassandraReactiveHealthIndicator.{sc-ext}[`CassandraReactiveHealthIndicator`] -|Checks that a Cassandra database is up. +| {sc-spring-boot-actuator}/cassandra/CassandraReactiveHealthIndicator.{sc-ext}[`CassandraReactiveHealthIndicator`] +| Checks that a Cassandra database is up. -|{sc-spring-boot-actuator}/couchbase/CouchbaseReactiveHealthIndicator.{sc-ext}[`CouchbaseReactiveHealthIndicator`] -|Checks that a Couchbase cluster is up. +| {sc-spring-boot-actuator}/couchbase/CouchbaseReactiveHealthIndicator.{sc-ext}[`CouchbaseReactiveHealthIndicator`] +| Checks that a Couchbase cluster is up. -|{sc-spring-boot-actuator}/mongo/MongoReactiveHealthIndicator.{sc-ext}[`MongoReactiveHealthIndicator`] -|Checks that a Mongo database is up. +| {sc-spring-boot-actuator}/mongo/MongoReactiveHealthIndicator.{sc-ext}[`MongoReactiveHealthIndicator`] +| Checks that a Mongo database is up. -|{sc-spring-boot-actuator}/redis/RedisReactiveHealthIndicator.{sc-ext}[`RedisReactiveHealthIndicator`] -|Checks that a Redis server is up. +| {sc-spring-boot-actuator}/redis/RedisReactiveHealthIndicator.{sc-ext}[`RedisReactiveHealthIndicator`] +| Checks that a Redis server is up. |=== -TIP: If necessary, reactive indicators replace the regular ones. Also, any -`HealthIndicator` that is not handled explicitly is wrapped automatically. +TIP: If necessary, reactive indicators replace the regular ones. +Also, any `HealthIndicator` that is not handled explicitly is wrapped automatically. [[production-ready-application-info]] === Application Information -Application information exposes various information collected from all -{sc-spring-boot-actuator}/info/InfoContributor.{sc-ext}[`InfoContributor`] beans defined -in your `ApplicationContext`. Spring Boot includes a number of auto-configured -`InfoContributor` beans, and you can write your own. +Application information exposes various information collected from all {sc-spring-boot-actuator}/info/InfoContributor.{sc-ext}[`InfoContributor`] beans defined in your `ApplicationContext`. +Spring Boot includes a number of auto-configured `InfoContributor` beans, and you can write your own. + + [[production-ready-application-info-autoconfigure]] ==== Auto-configured InfoContributors - -The following `InfoContributor` beans are auto-configured by Spring Boot, when -appropriate: +The following `InfoContributor` beans are auto-configured by Spring Boot, when appropriate: [cols="1,4"] |=== -|Name |Description +| Name | Description -|{sc-spring-boot-actuator}/info/EnvironmentInfoContributor.{sc-ext}[`EnvironmentInfoContributor`] -|Exposes any key from the `Environment` under the `info` key. +| {sc-spring-boot-actuator}/info/EnvironmentInfoContributor.{sc-ext}[`EnvironmentInfoContributor`] +| Exposes any key from the `Environment` under the `info` key. -|{sc-spring-boot-actuator}/info/GitInfoContributor.{sc-ext}[`GitInfoContributor`] -|Exposes git information if a `git.properties` file is available. +| {sc-spring-boot-actuator}/info/GitInfoContributor.{sc-ext}[`GitInfoContributor`] +| Exposes git information if a `git.properties` file is available. -|{sc-spring-boot-actuator}/info/BuildInfoContributor.{sc-ext}[`BuildInfoContributor`] -|Exposes build information if a `META-INF/build-info.properties` file is available. +| {sc-spring-boot-actuator}/info/BuildInfoContributor.{sc-ext}[`BuildInfoContributor`] +| Exposes build information if a `META-INF/build-info.properties` file is available. |=== -TIP: It is possible to disable them all by setting the `management.info.defaults.enabled` -property. +TIP: It is possible to disable them all by setting the `management.info.defaults.enabled` property. + + [[production-ready-application-info-env]] ==== Custom Application Information -You can customize the data exposed by the `info` endpoint by setting `+info.*+` Spring -properties. All `Environment` properties under the `info` key are automatically exposed. +You can customize the data exposed by the `info` endpoint by setting `+info.*+` Spring properties. +All `Environment` properties under the `info` key are automatically exposed. For example, you could add the following settings to your `application.properties` file: [source,properties,indent=0] @@ -990,8 +877,7 @@ For example, you could add the following settings to your `application.propertie [TIP] ==== -Rather than hardcoding those values, you could also -<>. +Rather than hardcoding those values, you could also <>. Assuming you use Maven, you could rewrite the preceding example as follows: @@ -1007,17 +893,13 @@ Assuming you use Maven, you could rewrite the preceding example as follows: [[production-ready-application-info-git]] ==== Git Commit Information -Another useful feature of the `info` endpoint is its ability to publish information about -the state of your `git` source code repository when the project was built. If a -`GitProperties` bean is available, the `git.branch`, `git.commit.id`, and -`git.commit.time` properties are exposed. +Another useful feature of the `info` endpoint is its ability to publish information about the state of your `git` source code repository when the project was built. +If a `GitProperties` bean is available, the `git.branch`, `git.commit.id`, and `git.commit.time` properties are exposed. -TIP: A `GitProperties` bean is auto-configured if a `git.properties` file is available at -the root of the classpath. See -"<>" for more details. +TIP: A `GitProperties` bean is auto-configured if a `git.properties` file is available at the root of the classpath. +See "<>" for more details. -If you want to display the full git information (that is, the full content of -`git.properties`), use the `management.info.git.mode` property, as follows: +If you want to display the full git information (that is, the full content of `git.properties`), use the `management.info.git.mode` property, as follows: [source,properties,indent=0] ---- @@ -1028,18 +910,17 @@ If you want to display the full git information (that is, the full content of [[production-ready-application-info-build]] ==== Build Information -If a `BuildProperties` bean is available, the `info` endpoint can also publish -information about your build. This happens if a `META-INF/build-info.properties` file is -available in the classpath. +If a `BuildProperties` bean is available, the `info` endpoint can also publish information about your build. +This happens if a `META-INF/build-info.properties` file is available in the classpath. + +TIP: The Maven and Gradle plugins can both generate that file. +See "<>" for more details. -TIP: The Maven and Gradle plugins can both generate that file. See -"<>" for more details. [[production-ready-application-info-custom]] ==== Writing Custom InfoContributors -To provide custom application information, you can register Spring beans that implement -the {sc-spring-boot-actuator}/info/InfoContributor.{sc-ext}[`InfoContributor`] interface. +To provide custom application information, you can register Spring beans that implement the {sc-spring-boot-actuator}/info/InfoContributor.{sc-ext}[`InfoContributor`] interface. The following example contributes an `example` entry with a single value: @@ -1063,8 +944,7 @@ The following example contributes an `example` entry with a single value: } ---- -If you reach the `info` endpoint, you should see a response that contains the following -additional entry: +If you reach the `info` endpoint, you should see a response that contains the following additional entry: [source,json,indent=0] ---- @@ -1076,40 +956,34 @@ additional entry: ---- + [[production-ready-monitoring]] == Monitoring and Management over HTTP -If you are developing a web application, Spring Boot Actuator auto-configures all -enabled endpoints to be exposed over HTTP. The default convention is to use the `id` of -the endpoint with a prefix of `/actuator` as the URL path. For example, `health` is -exposed as `/actuator/health`. +If you are developing a web application, Spring Boot Actuator auto-configures all enabled endpoints to be exposed over HTTP. +The default convention is to use the `id` of the endpoint with a prefix of `/actuator` as the URL path. +For example, `health` is exposed as `/actuator/health`. + TIP: Actuator is supported natively with Spring MVC, Spring WebFlux, and Jersey. [[production-ready-customizing-management-server-context-path]] === Customizing the Management Endpoint Paths -Sometimes, it is useful to customize the prefix for the management endpoints. For -example, your application might already use `/actuator` for another purpose. You can -use the `management.endpoints.web.base-path` property to change the prefix for your -management endpoint, as shown in the following example: +Sometimes, it is useful to customize the prefix for the management endpoints. +For example, your application might already use `/actuator` for another purpose. +You can use the `management.endpoints.web.base-path` property to change the prefix for your management endpoint, as shown in the following example: [source,properties,indent=0] ---- management.endpoints.web.base-path=/manage ---- -The preceding `application.properties` example changes the endpoint from -`/actuator/\{id}` to `/manage/\{id}` (for example, `/manage/info`). +The preceding `application.properties` example changes the endpoint from `/actuator/\{id}` to `/manage/\{id}` (for example, `/manage/info`). -NOTE: Unless the management port has been configured to -<>, `management.endpoints.web.base-path` is relative to -`server.servlet.context-path`. If `management.server.port` is configured, -`management.endpoints.web.base-path` is relative to -`management.server.servlet.context-path`. +NOTE: Unless the management port has been configured to <>, `management.endpoints.web.base-path` is relative to `server.servlet.context-path`. +If `management.server.port` is configured, `management.endpoints.web.base-path` is relative to `management.server.servlet.context-path`. -If you want to map endpoints to a different path, you can use the -`management.endpoints.web.path-mapping` property. +If you want to map endpoints to a different path, you can use the `management.endpoints.web.path-mapping` property. The following example remaps `/actuator/health` to `/healthcheck`: @@ -1124,30 +998,25 @@ The following example remaps `/actuator/health` to `/healthcheck`: [[production-ready-customizing-management-server-port]] === Customizing the Management Server Port -Exposing management endpoints by using the default HTTP port is a sensible choice for -cloud-based deployments. If, however, your application runs inside your own data center, -you may prefer to expose endpoints by using a different HTTP port. +Exposing management endpoints by using the default HTTP port is a sensible choice for cloud-based deployments. +If, however, your application runs inside your own data center, you may prefer to expose endpoints by using a different HTTP port. -You can set the `management.server.port` property to change the HTTP port, as shown in -the following example: +You can set the `management.server.port` property to change the HTTP port, as shown in the following example: [source,properties,indent=0] ---- management.server.port=8081 ---- -NOTE: On Cloud Foundry, applications only receive requests on port 8080 for both HTTP and TCP -routing, by default. If you want to use a custom management port on Cloud Foundry, you will need -to explicitly set up the application's routes to forward traffic to the custom port. +NOTE: On Cloud Foundry, applications only receive requests on port 8080 for both HTTP and TCP routing, by default. +If you want to use a custom management port on Cloud Foundry, you will need to explicitly set up the application's routes to forward traffic to the custom port. [[production-ready-management-specific-ssl]] === Configuring Management-specific SSL -When configured to use a custom port, the management server can also be configured with -its own SSL by using the various `management.server.ssl.*` properties. For example, doing -so lets a management server be available over HTTP while the main application uses HTTPS, -as shown in the following property settings: +When configured to use a custom port, the management server can also be configured with its own SSL by using the various `management.server.ssl.*` properties. +For example, doing so lets a management server be available over HTTP while the main application uses HTTPS, as shown in the following property settings: [source,properties,indent=0] ---- @@ -1159,8 +1028,7 @@ as shown in the following property settings: management.server.ssl.enabled=false ---- -Alternatively, both the main server and the management server can use SSL but with -different key stores, as follows: +Alternatively, both the main server and the management server can use SSL but with different key stores, as follows: [source,properties,indent=0] ---- @@ -1178,16 +1046,12 @@ different key stores, as follows: [[production-ready-customizing-management-server-address]] === Customizing the Management Server Address -You can customize the address that the management endpoints are available on by setting -the `management.server.address` property. Doing so can be useful if you want to listen -only on an internal or ops-facing network or to listen only for connections from -`localhost`. +You can customize the address that the management endpoints are available on by setting the `management.server.address` property. +Doing so can be useful if you want to listen only on an internal or ops-facing network or to listen only for connections from `localhost`. -NOTE: You can listen on a different address only when the port differs from the main -server port. +NOTE: You can listen on a different address only when the port differs from the main server port. -The following example `application.properties` does not allow remote management -connections: +The following example `application.properties` does not allow remote management connections: [source,properties,indent=0] ---- @@ -1199,16 +1063,14 @@ connections: [[production-ready-disabling-http-endpoints]] === Disabling HTTP Endpoints -If you do not want to expose endpoints over HTTP, you can set the management port to -`-1`, as shown in the following example: +If you do not want to expose endpoints over HTTP, you can set the management port to `-1`, as shown in the following example: [source,properties,indent=0] ---- management.server.port=-1 ---- -This can be achieved using the `management.endpoints.web.exposure.exclude` property as well, as shown in -following example: +This can be achieved using the `management.endpoints.web.exposure.exclude` property as well, as shown in following example: [source,properties,indent=0] ---- @@ -1219,23 +1081,21 @@ following example: [[production-ready-jmx]] == Monitoring and Management over JMX -Java Management Extensions (JMX) provide a standard mechanism to monitor and manage -applications. By default, Spring Boot exposes management endpoints as JMX MBeans under -the `org.springframework.boot` domain. +Java Management Extensions (JMX) provide a standard mechanism to monitor and manage applications. +By default, Spring Boot exposes management endpoints as JMX MBeans under the `org.springframework.boot` domain. [[production-ready-custom-mbean-names]] === Customizing MBean Names -The name of the MBean is usually generated from the `id` of the endpoint. For example, the -`health` endpoint is exposed as `org.springframework.boot:type=Endpoint,name=Health`. +The name of the MBean is usually generated from the `id` of the endpoint. +For example, the `health` endpoint is exposed as `org.springframework.boot:type=Endpoint,name=Health`. -If your application contains more than one Spring `ApplicationContext`, you may find that -names clash. To solve this problem, you can set the `spring.jmx.unique-names` property to -`true` so that MBean names are always unique. +If your application contains more than one Spring `ApplicationContext`, you may find that names clash. +To solve this problem, you can set the `spring.jmx.unique-names` property to `true` so that MBean names are always unique. -You can also customize the JMX domain under which endpoints are exposed. The following -settings show an example of doing so in `application.properties`: +You can also customize the JMX domain under which endpoints are exposed. +The following settings show an example of doing so in `application.properties`: [source,properties,indent=0] ---- @@ -1247,9 +1107,7 @@ settings show an example of doing so in `application.properties`: [[production-ready-disable-jmx-endpoints]] === Disabling JMX Endpoints -If you do not want to expose endpoints over JMX, you can set the -`management.endpoints.jmx.exposure.exclude` property to `*`, as shown in the following -example: +If you do not want to expose endpoints over JMX, you can set the `management.endpoints.jmx.exposure.exclude` property to `*`, as shown in the following example: [source,properties,indent=0] ---- @@ -1261,8 +1119,8 @@ example: [[production-ready-jolokia]] === Using Jolokia for JMX over HTTP Jolokia is a JMX-HTTP bridge that provides an alternative method of accessing JMX beans. -To use Jolokia, include a dependency to `org.jolokia:jolokia-core`. For example, with -Maven, you would add the following dependency: +To use Jolokia, include a dependency to `org.jolokia:jolokia-core`. +For example, with Maven, you would add the following dependency: [source,xml,indent=0] ---- @@ -1272,18 +1130,16 @@ Maven, you would add the following dependency: ---- -The Jolokia endpoint can then be exposed by adding `jolokia` or `*` to the -`management.endpoints.web.exposure.include` property. You can then access it by using -`/actuator/jolokia` on your management HTTP server. +The Jolokia endpoint can then be exposed by adding `jolokia` or `*` to the `management.endpoints.web.exposure.include` property. +You can then access it by using `/actuator/jolokia` on your management HTTP server. [[production-ready-customizing-jolokia]] ==== Customizing Jolokia -Jolokia has a number of settings that you would traditionally configure by setting servlet -parameters. With Spring Boot, you can use your `application.properties` file. To do so, -prefix the parameter with `management.endpoint.jolokia.config.`, as shown in the following -example: +Jolokia has a number of settings that you would traditionally configure by setting servlet parameters. +With Spring Boot, you can use your `application.properties` file. +To do so, prefix the parameter with `management.endpoint.jolokia.config.`, as shown in the following example: [source,properties,indent=0] ---- @@ -1294,8 +1150,7 @@ example: [[production-ready-disabling-jolokia]] ==== Disabling Jolokia -If you use Jolokia but do not want Spring Boot to configure it, set the -`management.endpoint.jolokia.enabled` property to `false`, as follows: +If you use Jolokia but do not want Spring Boot to configure it, set the `management.endpoint.jolokia.enabled` property to `false`, as follows: [source,properties,indent=0] ---- @@ -1306,11 +1161,9 @@ If you use Jolokia but do not want Spring Boot to configure it, set the [[production-ready-loggers]] == Loggers -Spring Boot Actuator includes the ability to view and configure the log levels of your -application at runtime. You can view either the entire list or an individual logger's -configuration, which is made up of both the explicitly configured logging level as well -as the effective logging level given to it by the logging framework. These levels can be -one of: +Spring Boot Actuator includes the ability to view and configure the log levels of your application at runtime. +You can view either the entire list or an individual logger's configuration, which is made up of both the explicitly configured logging level as well as the effective logging level given to it by the logging framework. +These levels can be one of: * `TRACE` * `DEBUG` @@ -1327,8 +1180,7 @@ one of: [[production-ready-logger-configuration]] === Configure a Logger -To configure a given logger, `POST` a partial entity to the resource's URI, as shown in -the following example: +To configure a given logger, `POST` a partial entity to the resource's URI, as shown in the following example: [source,json,indent=0] ---- @@ -1337,16 +1189,13 @@ the following example: } ---- -TIP: To "`reset`" the specific level of the logger (and use the default configuration -instead), you can pass a value of `null` as the `configuredLevel`. +TIP: To "`reset`" the specific level of the logger (and use the default configuration instead), you can pass a value of `null` as the `configuredLevel`. [[production-ready-metrics]] == Metrics -Spring Boot Actuator provides dependency management and auto-configuration for -https://micrometer.io[Micrometer], an application metrics facade that supports numerous -monitoring systems, including: +Spring Boot Actuator provides dependency management and auto-configuration for https://micrometer.io[Micrometer], an application metrics facade that supports numerous monitoring systems, including: - <> - <> @@ -1366,39 +1215,32 @@ monitoring systems, including: - <> - <> -TIP: To learn more about Micrometer's capabilities, please refer to its -https://micrometer.io/docs[reference documentation], in particular the -{micrometer-concepts-documentation}[concepts section]. +TIP: To learn more about Micrometer's capabilities, please refer to its https://micrometer.io/docs[reference documentation], in particular the {micrometer-concepts-documentation}[concepts section]. [[production-ready-metrics-getting-started]] === Getting started -Spring Boot auto-configures a composite `MeterRegistry` and adds a registry to the -composite for each of the supported implementations that it finds on the classpath. Having -a dependency on `micrometer-registry-\{system}` in your runtime classpath is enough for -Spring Boot to configure the registry. +Spring Boot auto-configures a composite `MeterRegistry` and adds a registry to the composite for each of the supported implementations that it finds on the classpath. +Having a dependency on `micrometer-registry-\{system}` in your runtime classpath is enough for Spring Boot to configure the registry. -Most registries share common features. For instance, you can disable a particular registry -even if the Micrometer registry implementation is on the classpath. For instance, to -disable Datadog: +Most registries share common features. +For instance, you can disable a particular registry even if the Micrometer registry implementation is on the classpath. +For example, to disable Datadog: [source,properties,indent=0] ---- management.metrics.export.datadog.enabled=false ---- -Spring Boot will also add any auto-configured registries to the global static composite -registry on the `Metrics` class unless you explicitly tell it not to: +Spring Boot will also add any auto-configured registries to the global static composite registry on the `Metrics` class unless you explicitly tell it not to: [source,properties,indent=0] ---- management.metrics.use-global-registry=false ---- -You can register any number of `MeterRegistryCustomizer` beans to further configure the -registry, such as applying common tags, before any meters are registered with the -registry: +You can register any number of `MeterRegistryCustomizer` beans to further configure the registry, such as applying common tags, before any meters are registered with the registry: [source,java,indent=0] ---- @@ -1408,8 +1250,7 @@ registry: } ---- -You can apply customizations to particular registry implementations by being more specific -about the generic type: +You can apply customizations to particular registry implementations by being more specific about the generic type: [source,java,indent=0] ---- @@ -1419,17 +1260,14 @@ about the generic type: } ---- -With that setup in place you can inject `MeterRegistry` in your components and register -metrics: +With that setup in place you can inject `MeterRegistry` in your components and register metrics: [source,java,indent=0] ---- include::{code-examples}/actuate/metrics/SampleBean.java[tag=example] ---- -Spring Boot also <> -(i.e. `MeterBinder` implementations) that you can control via configuration or dedicated -annotation markers. +Spring Boot also <> (i.e. `MeterBinder` implementations) that you can control via configuration or dedicated annotation markers. @@ -1440,9 +1278,8 @@ annotation markers. [[production-ready-metrics-export-appoptics]] ==== AppOptics -By default, the AppOptics registry pushes metrics to -https://api.appoptics.com/v1/measurements periodically. To export metrics to SaaS -{micrometer-registry-documentation}/appoptics[AppOptics], your API token must be provided: +By default, the AppOptics registry pushes metrics to https://api.appoptics.com/v1/measurements periodically. +To export metrics to SaaS {micrometer-registry-documentation}/appoptics[AppOptics], your API token must be provided: [source,properties,indent=0] ---- @@ -1453,9 +1290,8 @@ https://api.appoptics.com/v1/measurements periodically. To export metrics to Saa [[production-ready-metrics-export-atlas]] ==== Atlas -By default, metrics are exported to {micrometer-registry-documentation}/atlas[Atlas] -running on your local machine. The location of the -https://github.com/Netflix/atlas[Atlas server] to use can be provided using: +By default, metrics are exported to {micrometer-registry-documentation}/atlas[Atlas] running on your local machine. +The location of the https://github.com/Netflix/atlas[Atlas server] to use can be provided using: [source,properties,indent=0] ---- @@ -1466,9 +1302,8 @@ https://github.com/Netflix/atlas[Atlas server] to use can be provided using: [[production-ready-metrics-export-datadog]] ==== Datadog -Datadog registry pushes metrics to https://www.datadoghq.com[datadoghq] periodically. To -export metrics to {micrometer-registry-documentation}/datadog[Datadog], your API key must -be provided: +Datadog registry pushes metrics to https://www.datadoghq.com[datadoghq] periodically. +To export metrics to {micrometer-registry-documentation}/datadog[Datadog], your API key must be provided: [source,properties,indent=0] ---- @@ -1486,9 +1321,8 @@ You can also change the interval at which metrics are sent to Datadog: [[production-ready-metrics-export-dynatrace]] ==== Dynatrace -Dynatrace registry pushes metrics to the configured URI periodically. To export metrics to -{micrometer-registry-documentation}/dynatrace[Dynatrace], your API token, device ID, and -URI must be provided: +Dynatrace registry pushes metrics to the configured URI periodically. +To export metrics to {micrometer-registry-documentation}/dynatrace[Dynatrace], your API token, device ID, and URI must be provided: [source,properties,indent=0] ---- @@ -1508,9 +1342,8 @@ You can also change the interval at which metrics are sent to Dynatrace: [[production-ready-metrics-export-elastic]] ==== Elastic -By default, metrics are exported to {micrometer-registry-documentation}/elastic[Elastic] -running on your local machine. The location of the Elastic server to use can be provided -using the following property: +By default, metrics are exported to {micrometer-registry-documentation}/elastic[Elastic] running on your local machine. +The location of the Elastic server to use can be provided using the following property: [source,properties,indent=0] ---- @@ -1521,9 +1354,8 @@ using the following property: [[production-ready-metrics-export-ganglia]] ==== Ganglia -By default, metrics are exported to {micrometer-registry-documentation}/ganglia[Ganglia] -running on your local machine. The http://ganglia.sourceforge.net[Ganglia server] host and -port to use can be provided using: +By default, metrics are exported to {micrometer-registry-documentation}/ganglia[Ganglia] running on your local machine. +The http://ganglia.sourceforge.net[Ganglia server] host and port to use can be provided using: [source,properties,indent=0] ---- @@ -1535,9 +1367,8 @@ port to use can be provided using: [[production-ready-metrics-export-graphite]] ==== Graphite -By default, metrics are exported to {micrometer-registry-documentation}/graphite[Graphite] -running on your local machine. The https://graphiteapp.org[Graphite server] host and port -to use can be provided using: +By default, metrics are exported to {micrometer-registry-documentation}/graphite[Graphite] running on your local machine. +The https://graphiteapp.org[Graphite server] host and port to use can be provided using: [source,properties,indent=0] ---- @@ -1545,13 +1376,10 @@ to use can be provided using: management.metrics.export.graphite.port=9004 ---- -Micrometer provides a default `HierarchicalNameMapper` that governs how a dimensional -meter id is {micrometer-registry-documentation}/graphite#_hierarchical_name_mapping[mapped -to flat hierarchical names]. +Micrometer provides a default `HierarchicalNameMapper` that governs how a dimensional meter id is {micrometer-registry-documentation}/graphite#_hierarchical_name_mapping[mapped to flat hierarchical names]. -TIP: To take control over this behaviour, define your `GraphiteMeterRegistry` and supply -your own `HierarchicalNameMapper`. An auto-configured `GraphiteConfig` and `Clock` beans -are provided unless you define your own: +TIP: To take control over this behaviour, define your `GraphiteMeterRegistry` and supply your own `HierarchicalNameMapper`. +An auto-configured `GraphiteConfig` and `Clock` beans are provided unless you define your own: [source,java] ---- @@ -1565,17 +1393,15 @@ public GraphiteMeterRegistry graphiteMeterRegistry(GraphiteConfig config, Clock [[production-ready-metrics-export-humio]] ==== Humio -By default, the Humio registry pushes metrics to https://cloud.humio.com periodically. To -export metrics to SaaS {micrometer-registry-documentation}/humio[Humio], your API token -must be provided: +By default, the Humio registry pushes metrics to https://cloud.humio.com periodically. +To export metrics to SaaS {micrometer-registry-documentation}/humio[Humio], your API token must be provided: [source,properties,indent=0] ---- management.metrics.export.humio.api-token=YOUR_TOKEN ---- -You should also configure one or more tags to identify the data source to which metrics -will be pushed: +You should also configure one or more tags to identify the data source to which metrics will be pushed: [source,properties,indent=0] ---- @@ -1587,9 +1413,8 @@ will be pushed: [[production-ready-metrics-export-influx]] ==== Influx -By default, metrics are exported to {micrometer-registry-documentation}/influx[Influx] -running on your local machine. The location of the https://www.influxdata.com[Influx -server] to use can be provided using: +By default, metrics are exported to {micrometer-registry-documentation}/influx[Influx] running on your local machine. +The location of the https://www.influxdata.com[Influx server] to use can be provided using: [source,properties,indent=0] ---- @@ -1600,23 +1425,19 @@ server] to use can be provided using: [[production-ready-metrics-export-jmx]] ==== JMX -Micrometer provides a hierarchical mapping to -{micrometer-registry-documentation}/jmx[JMX], primarily as a cheap and portable way to -view metrics locally. By default, metrics are exported to the `metrics` JMX domain. The -domain to use can be provided using: +Micrometer provides a hierarchical mapping to {micrometer-registry-documentation}/jmx[JMX], primarily as a cheap and portable way to view metrics locally. +By default, metrics are exported to the `metrics` JMX domain. +The domain to use can be provided using: [source,properties,indent=0] ---- management.metrics.export.jmx.domain=com.example.app.metrics ---- -Micrometer provides a default `HierarchicalNameMapper` that governs how a dimensional -meter id is {micrometer-registry-documentation}/jmx#_hierarchical_name_mapping[mapped to -flat hierarchical names]. +Micrometer provides a default `HierarchicalNameMapper` that governs how a dimensional meter id is {micrometer-registry-documentation}/jmx#_hierarchical_name_mapping[mapped to flat hierarchical names]. -TIP: To take control over this behaviour, define your `JmxMeterRegistry` and supply your -own `HierarchicalNameMapper`. An auto-configured `JmxConfig` and `Clock` beans are -provided unless you define your own: +TIP: To take control over this behaviour, define your `JmxMeterRegistry` and supply your own `HierarchicalNameMapper`. +An auto-configured `JmxConfig` and `Clock` beans are provided unless you define your own: [source,java] ---- @@ -1630,9 +1451,8 @@ public JmxMeterRegistry jmxMeterRegistry(JmxConfig config, Clock clock) { [[production-ready-metrics-export-kairos]] ==== KairosDB -By default, metrics are exported to {micrometer-registry-documentation}/kairos[KairosDB] -running on your local machine. The location of the https://kairosdb.github.io/[KairosDB -server] to use can be provided using: +By default, metrics are exported to {micrometer-registry-documentation}/kairos[KairosDB] running on your local machine. +The location of the https://kairosdb.github.io/[KairosDB server] to use can be provided using: [source,properties,indent=0] ---- @@ -1643,9 +1463,8 @@ server] to use can be provided using: [[production-ready-metrics-export-newrelic]] ==== New Relic -New Relic registry pushes metrics to {micrometer-registry-documentation}/new-relic[New -Relic] periodically. To export metrics to https://newrelic.com[New Relic], your API key -and account id must be provided: +New Relic registry pushes metrics to {micrometer-registry-documentation}/new-relic[New Relic] periodically. +To export metrics to https://newrelic.com[New Relic], your API key and account id must be provided: [source,properties,indent=0] ---- @@ -1664,13 +1483,10 @@ You can also change the interval at which metrics are sent to New Relic: [[production-ready-metrics-export-prometheus]] ==== Prometheus -{micrometer-registry-documentation}/prometheus[Prometheus] expects to scrape or poll -individual app instances for metrics. Spring Boot provides an actuator endpoint available -at `/actuator/prometheus` to present a https://prometheus.io[Prometheus scrape] with the -appropriate format. +{micrometer-registry-documentation}/prometheus[Prometheus] expects to scrape or poll individual app instances for metrics. +Spring Boot provides an actuator endpoint available at `/actuator/prometheus` to present a https://prometheus.io[Prometheus scrape] with the appropriate format. -TIP: The endpoint is not available by default and must be exposed, see -<> for more details. +TIP: The endpoint is not available by default and must be exposed, see <> for more details. Here is an example `scrape_config` to add to `prometheus.yml`: @@ -1683,10 +1499,8 @@ Here is an example `scrape_config` to add to `prometheus.yml`: - targets: ['HOST:PORT'] ---- -For ephemeral or batch jobs which may not exist long enough to be scraped, -https://github.com/prometheus/pushgateway[Prometheus Pushgateway] support can be used to -expose their metrics to Prometheus. To enable Prometheus Pushgateway support, add the following -dependency to your project: +For ephemeral or batch jobs which may not exist long enough to be scraped, https://github.com/prometheus/pushgateway[Prometheus Pushgateway] support can be used to expose their metrics to Prometheus. +To enable Prometheus Pushgateway support, add the following dependency to your project: [source,xml,indent=0] ---- @@ -1696,8 +1510,8 @@ dependency to your project: ---- -When the Prometheus Pushgateway dependency is present on the classpath, Spring Boot auto-configures -a `PrometheusPushGatewayManager` bean. This manages the pushing of metrics to a Prometheus Pushgateway. +When the Prometheus Pushgateway dependency is present on the classpath, Spring Boot auto-configures a `PrometheusPushGatewayManager` bean. +This manages the pushing of metrics to a Prometheus Pushgateway. The `PrometheusPushGatewayManager` can be tuned using properties under `management.metrics.export.prometheus.pushgateway`. For advanced configuration, you can also provide your own `PrometheusPushGatewayManager` bean. @@ -1705,9 +1519,8 @@ For advanced configuration, you can also provide your own `PrometheusPushGateway [[production-ready-metrics-export-signalfx]] ==== SignalFx -SignalFx registry pushes metrics to {micrometer-registry-documentation}/signalfx[SignalFx] -periodically. To export metrics to https://signalfx.com[SignalFx], your access token must -be provided: +SignalFx registry pushes metrics to {micrometer-registry-documentation}/signalfx[SignalFx] periodically. +To export metrics to https://signalfx.com[SignalFx], your access token must be provided: [source,properties,indent=0] ---- @@ -1725,12 +1538,11 @@ You can also change the interval at which metrics are sent to SignalFx: [[production-ready-metrics-export-simple]] ==== Simple -Micrometer ships with a simple, in-memory backend that is automatically used as a fallback -if no other registry is configured. This allows you to see what metrics are collected in -the <>. +Micrometer ships with a simple, in-memory backend that is automatically used as a fallback if no other registry is configured. +This allows you to see what metrics are collected in the <>. -The in-memory backend disables itself as soon as you're using any of the other available -backend. You can also disable it explicitly: +The in-memory backend disables itself as soon as you're using any of the other available backend. +You can also disable it explicitly: [source,properties,indent=0] ---- @@ -1741,9 +1553,9 @@ backend. You can also disable it explicitly: [[production-ready-metrics-export-statsd]] ==== StatsD -The StatsD registry pushes metrics over UDP to a StatsD agent eagerly. By default, metrics -are exported to a {micrometer-registry-documentation}/statsd[StatsD] agent running on your -local machine. The StatsD agent host and port to use can be provided using: +The StatsD registry pushes metrics over UDP to a StatsD agent eagerly. +By default, metrics are exported to a {micrometer-registry-documentation}/statsd[StatsD] agent running on your local machine. +The StatsD agent host and port to use can be provided using: [source,properties,indent=0] ---- @@ -1762,27 +1574,22 @@ You can also change the StatsD line protocol to use (default to Datadog): [[production-ready-metrics-export-wavefront]] ==== Wavefront -Wavefront registry pushes metrics to -{micrometer-registry-documentation}/wavefront[Wavefront] periodically. If you are -exporting metrics to https://www.wavefront.com/[Wavefront] directly, your API token must -be provided: +Wavefront registry pushes metrics to {micrometer-registry-documentation}/wavefront[Wavefront] periodically. +If you are exporting metrics to https://www.wavefront.com/[Wavefront] directly, your API token must be provided: [source,properties,indent=0] ---- management.metrics.export.wavefront.api-token=YOUR_API_TOKEN ---- -Alternatively, you may use a Wavefront sidecar or an internal proxy set up in your -environment that forwards metrics data to the Wavefront API host: +Alternatively, you may use a Wavefront sidecar or an internal proxy set up in your environment that forwards metrics data to the Wavefront API host: [source,properties,indent=0] ---- management.metrics.export.wavefront.uri=proxy://localhost:2878 ---- -TIP: If publishing metrics to a Wavefront proxy (as described in -https://docs.wavefront.com/proxies_installing.html[the documentation]), the host must be -in the `proxy://HOST:PORT` format. +TIP: If publishing metrics to a Wavefront proxy (as described in https://docs.wavefront.com/proxies_installing.html[the documentation]), the host must be in the `proxy://HOST:PORT` format. You can also change the interval at which metrics are sent to Wavefront: @@ -1807,8 +1614,7 @@ Spring Boot registers the following core metrics when applicable: * Kafka consumer metrics * Log4j2 metrics: record the number of events logged to Log4j2 at each level * Logback metrics: record the number of events logged to Logback at each level -* Uptime metrics: report a gauge for uptime and a fixed gauge representing the -application's absolute start time +* Uptime metrics: report a gauge for uptime and a fixed gauge representing the application's absolute start time * Tomcat metrics * {spring-integration-reference}#micrometer-integration[Spring Integration] metrics @@ -1816,10 +1622,9 @@ application's absolute start time [[production-ready-metrics-spring-mvc]] ==== Spring MVC Metrics -Auto-configuration enables the instrumentation of requests handled by Spring MVC. When -`management.metrics.web.server.auto-time-requests` is `true`, this instrumentation occurs -for all requests. Alternatively, when set to `false`, you can enable instrumentation by -adding `@Timed` to a request-handling method: +Auto-configuration enables the instrumentation of requests handled by Spring MVC. +When `management.metrics.web.server.auto-time-requests` is `true`, this instrumentation occurs for all requests. +Alternatively, when set to `false`, you can enable instrumentation by adding `@Timed` to a request-handling method: [source,java,indent=0] ---- @@ -1835,37 +1640,33 @@ adding `@Timed` to a request-handling method: } ---- <1> A controller class to enable timings on every request handler in the controller. -<2> A method to enable for an individual endpoint. This is not necessary if you have it on -the class, but can be used to further customize the timer for this particular endpoint. -<3> A method with `longTask = true` to enable a long task timer for the method. Long task -timers require a separate metric name, and can be stacked with a short task timer. +<2> A method to enable for an individual endpoint. + This is not necessary if you have it on the class, but can be used to further customize the timer for this particular endpoint. +<3> A method with `longTask = true` to enable a long task timer for the method. + Long task timers require a separate metric name, and can be stacked with a short task timer. -By default, metrics are generated with the name, `http.server.requests`. The name can be -customized by setting the `management.metrics.web.server.requests-metric-name` property. +By default, metrics are generated with the name, `http.server.requests`. +The name can be customized by setting the `management.metrics.web.server.requests-metric-name` property. By default, Spring MVC-related metrics are tagged with the following information: |=== -|Tag |Description +| Tag | Description -|`exception` -|Simple class name of any exception that was thrown while handling the request. +| `exception` +| Simple class name of any exception that was thrown while handling the request. -|`method` -|Request's method (for example, `GET` or `POST`) +| `method` +| Request's method (for example, `GET` or `POST`) -|`outcome` -|Request's outcome based on the status code of the response. 1xx is -`INFORMATIONAL`, 2xx is `SUCCESS`, 3xx is `REDIRECTION`, 4xx `CLIENT_ERROR`, and 5xx is -`SERVER_ERROR` +| `outcome` +| Request's outcome based on the status code of the response. 1xx is `INFORMATIONAL`, 2xx is `SUCCESS`, 3xx is `REDIRECTION`, 4xx `CLIENT_ERROR`, and 5xx is `SERVER_ERROR` -|`status` -|Response's HTTP status code (for example, `200` or `500`) - -|`uri` -|Request's URI template prior to variable substitution, if possible (for example, -`/api/person/\{id}`) +| `status` +| Response's HTTP status code (for example, `200` or `500`) +| `uri` +| Request's URI template prior to variable substitution, if possible (for example, `/api/person/\{id}`) |=== To customize the tags, provide a `@Bean` that implements `WebMvcTagsProvider`. @@ -1874,35 +1675,30 @@ To customize the tags, provide a `@Bean` that implements `WebMvcTagsProvider`. [[production-ready-metrics-web-flux]] ==== Spring WebFlux Metrics -Auto-configuration enables the instrumentation of all requests handled by WebFlux -controllers and functional handlers. +Auto-configuration enables the instrumentation of all requests handled by WebFlux controllers and functional handlers. -By default, metrics are generated with the name `http.server.requests`. You can customize -the name by setting the `management.metrics.web.server.requests-metric-name` property. +By default, metrics are generated with the name `http.server.requests`. +You can customize the name by setting the `management.metrics.web.server.requests-metric-name` property. By default, WebFlux-related metrics are tagged with the following information: |=== -|Tag |Description +| Tag | Description -|`exception` -|Simple class name of any exception that was thrown while handling the request. +| `exception` +| Simple class name of any exception that was thrown while handling the request. -|`method` -|Request's method (for example, `GET` or `POST`) +| `method` +| Request's method (for example, `GET` or `POST`) -|`outcome` -|Request's outcome based on the status code of the response. 1xx is -`INFORMATIONAL`, 2xx is `SUCCESS`, 3xx is `REDIRECTION`, 4xx `CLIENT_ERROR`, and 5xx is -`SERVER_ERROR` +| `outcome` +| Request's outcome based on the status code of the response. 1xx is `INFORMATIONAL`, 2xx is `SUCCESS`, 3xx is `REDIRECTION`, 4xx `CLIENT_ERROR`, and 5xx is `SERVER_ERROR` -|`status` -|Response's HTTP status code (for example, `200` or `500`) - -|`uri` -|Request's URI template prior to variable substitution, if possible (for example, -`/api/person/\{id}`) +| `status` +| Response's HTTP status code (for example, `200` or `500`) +| `uri` +| Request's URI template prior to variable substitution, if possible (for example, `/api/person/\{id}`) |=== To customize the tags, provide a `@Bean` that implements `WebFluxTagsProvider`. @@ -1911,10 +1707,9 @@ To customize the tags, provide a `@Bean` that implements `WebFluxTagsProvider`. [[production-ready-metrics-jersey-server]] ==== Jersey Server Metrics -Auto-configuration enables the instrumentation of requests handled by the Jersey JAX-RS -implementation. When `management.metrics.web.server.auto-time-requests` is `true`, this -instrumentation occurs for all requests. Alternatively, when set to `false`, you can -enable instrumentation by adding `@Timed` to a request-handling method: +Auto-configuration enables the instrumentation of requests handled by the Jersey JAX-RS implementation. +When `management.metrics.web.server.auto-time-requests` is `true`, this instrumentation occurs for all requests. +Alternatively, when set to `false`, you can enable instrumentation by adding `@Timed` to a request-handling method: [source,java,indent=0] ---- @@ -1929,37 +1724,33 @@ enable instrumentation by adding `@Timed` to a request-handling method: } ---- <1> On a resource class to enable timings on every request handler in the resource. -<2> On a method to enable for an individual endpoint. This is not necessary if you have it on -the class, but can be used to further customize the timer for this particular endpoint. -<3> On a method with `longTask = true` to enable a long task timer for the method. Long task -timers require a separate metric name, and can be stacked with a short task timer. +<2> On a method to enable for an individual endpoint. + This is not necessary if you have it on the class, but can be used to further customize the timer for this particular endpoint. +<3> On a method with `longTask = true` to enable a long task timer for the method. + Long task timers require a separate metric name, and can be stacked with a short task timer. -By default, metrics are generated with the name, `http.server.requests`. The name can be -customized by setting the `management.metrics.web.server.requests-metric-name` property. +By default, metrics are generated with the name, `http.server.requests`. +The name can be customized by setting the `management.metrics.web.server.requests-metric-name` property. By default, Jersey server metrics are tagged with the following information: |=== -|Tag |Description +| Tag | Description -|`exception` -|Simple class name of any exception that was thrown while handling the request. +| `exception` +| Simple class name of any exception that was thrown while handling the request. -|`method` -|Request's method (for example, `GET` or `POST`) +| `method` +| Request's method (for example, `GET` or `POST`) -|`outcome` -|Request's outcome based on the status code of the response. 1xx is -`INFORMATIONAL`, 2xx is `SUCCESS`, 3xx is `REDIRECTION`, 4xx `CLIENT_ERROR`, and 5xx is -`SERVER_ERROR` +| `outcome` +| Request's outcome based on the status code of the response. 1xx is `INFORMATIONAL`, 2xx is `SUCCESS`, 3xx is `REDIRECTION`, 4xx `CLIENT_ERROR`, and 5xx is `SERVER_ERROR` -|`status` -|Response's HTTP status code (for example, `200` or `500`) - -|`uri` -|Request's URI template prior to variable substitution, if possible (for example, -`/api/person/\{id}`) +| `status` +| Response's HTTP status code (for example, `200` or `500`) +| `uri` +| Request's URI template prior to variable substitution, if possible (for example, `/api/person/\{id}`) |=== To customize the tags, provide a `@Bean` that implements `JerseyTagsProvider`. @@ -1969,39 +1760,33 @@ To customize the tags, provide a `@Bean` that implements `JerseyTagsProvider`. [[production-ready-metrics-http-clients]] ==== HTTP Client Metrics Spring Boot Actuator manages the instrumentation of both `RestTemplate` and `WebClient`. -For that, you have to get injected with an auto-configured builder -and use it to create instances: +For that, you have to get injected with an auto-configured builder and use it to create instances: * `RestTemplateBuilder` for `RestTemplate` * `WebClient.Builder` for `WebClient` -It is also possible to apply manually the customizers responsible for this instrumentation, -namely `MetricsRestTemplateCustomizer` and `MetricsWebClientCustomizer`. +It is also possible to apply manually the customizers responsible for this instrumentation, namely `MetricsRestTemplateCustomizer` and `MetricsWebClientCustomizer`. -By default, metrics are generated with the name, `http.client.requests`. The name can be -customized by setting the `management.metrics.web.client.requests-metric-name` property. +By default, metrics are generated with the name, `http.client.requests`. +The name can be customized by setting the `management.metrics.web.client.requests-metric-name` property. -By default, metrics generated by an instrumented client are tagged with the -following information: +By default, metrics generated by an instrumented client are tagged with the following information: * `method`, the request's method (for example, `GET` or `POST`). -* `uri`, the request's URI template prior to variable substitution, if possible (for -example, `/api/person/\{id}`). +* `uri`, the request's URI template prior to variable substitution, if possible (for example, `/api/person/\{id}`). * `status`, the response's HTTP status code (for example, `200` or `500`). * `clientName`, the host portion of the URI. -To customize the tags, and depending on your choice of client, you can provide -a `@Bean` that implements `RestTemplateExchangeTagsProvider` or -`WebClientExchangeTagsProvider`. There are convenience static functions in -`RestTemplateExchangeTags` and `WebClientExchangeTags`. +To customize the tags, and depending on your choice of client, you can provide a `@Bean` that implements `RestTemplateExchangeTagsProvider` or `WebClientExchangeTagsProvider`. +There are convenience static functions in `RestTemplateExchangeTags` and `WebClientExchangeTags`. [[production-ready-metrics-cache]] ==== Cache Metrics -Auto-configuration enables the instrumentation of all available ``Cache``s on startup -with metrics prefixed with `cache`. Cache instrumentation is standardized for a basic set -of metrics. Additional, cache-specific metrics are also available. +Auto-configuration enables the instrumentation of all available ``Cache``s on startup with metrics prefixed with `cache`. +Cache instrumentation is standardized for a basic set of metrics. +Additional, cache-specific metrics are also available. The following cache libraries are supported: @@ -2010,45 +1795,37 @@ The following cache libraries are supported: * Hazelcast * Any compliant JCache (JSR-107) implementation -Metrics are tagged by the name of the cache and by the name of the `CacheManager` that is -derived from the bean name. +Metrics are tagged by the name of the cache and by the name of the `CacheManager` that is derived from the bean name. -NOTE: Only caches that are available on startup are bound to the registry. For caches -created on-the-fly or programmatically after the startup phase, an explicit registration -is required. A `CacheMetricsRegistrar` bean is made available to make that process easier. +NOTE: Only caches that are available on startup are bound to the registry. +For caches created on-the-fly or programmatically after the startup phase, an explicit registration is required. +A `CacheMetricsRegistrar` bean is made available to make that process easier. [[production-ready-metrics-jdbc]] ==== DataSource Metrics -Auto-configuration enables the instrumentation of all available `DataSource` objects with -metrics prefixed with `jdbc.connections`. Data source instrumentation results in gauges -representing the currently active, maximum allowed, and minimum allowed connections in the -pool. +Auto-configuration enables the instrumentation of all available `DataSource` objects with metrics prefixed with `jdbc.connections`. +Data source instrumentation results in gauges representing the currently active, maximum allowed, and minimum allowed connections in the pool. Metrics are also tagged by the name of the `DataSource` computed based on the bean name. -TIP: By default, Spring Boot provides metadata for all supported data sources; you can -add additional `DataSourcePoolMetadataProvider` beans if your favorite data source isn't -supported out of the box. See `DataSourcePoolMetadataProvidersConfiguration` for examples. +TIP: By default, Spring Boot provides metadata for all supported data sources; you can add additional `DataSourcePoolMetadataProvider` beans if your favorite data source isn't supported out of the box. +See `DataSourcePoolMetadataProvidersConfiguration` for examples. -Also, Hikari-specific metrics are exposed with a `hikaricp` prefix. Each metric is tagged -by the name of the Pool (can be controlled with `spring.datasource.name`). +Also, Hikari-specific metrics are exposed with a `hikaricp` prefix. +Each metric is tagged by the name of the Pool (can be controlled with `spring.datasource.name`). [[production-ready-metrics-hibernate]] ==== Hibernate Metrics -Auto-configuration enables the instrumentation of all available Hibernate -`EntityManagerFactory` instances that have statistics enabled with a metric named -`hibernate`. +Auto-configuration enables the instrumentation of all available Hibernate `EntityManagerFactory` instances that have statistics enabled with a metric named `hibernate`. -Metrics are also tagged by the name of the `EntityManagerFactory` that is derived from -the bean name. +Metrics are also tagged by the name of the `EntityManagerFactory` that is derived from the bean name. -To enable statistics, the standard JPA property `hibernate.generate_statistics` must be -set to `true`. You can enable that on the auto-configured `EntityManagerFactory` as shown -in the following example: +To enable statistics, the standard JPA property `hibernate.generate_statistics` must be set to `true`. +You can enable that on the auto-configured `EntityManagerFactory` as shown in the following example: [source,properties,indent=0] ---- @@ -2059,47 +1836,42 @@ in the following example: [[production-ready-metrics-rabbitmq]] ==== RabbitMQ Metrics -Auto-configuration will enable the instrumentation of all available RabbitMQ connection -factories with a metric named `rabbitmq`. +Auto-configuration will enable the instrumentation of all available RabbitMQ connection factories with a metric named `rabbitmq`. [[production-ready-metrics-custom]] === Registering custom metrics -To register custom metrics, inject `MeterRegistry` into your component, as shown in the -following example: +To register custom metrics, inject `MeterRegistry` into your component, as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/actuate/metrics/MetricsMeterRegistryInjectionExample.java[tag=component] ---- -If you find that you repeatedly instrument a suite of metrics across components or -applications, you may encapsulate this suite in a `MeterBinder` implementation. By -default, metrics from all `MeterBinder` beans will be automatically bound to -the Spring-managed `MeterRegistry`. +If you find that you repeatedly instrument a suite of metrics across components or applications, you may encapsulate this suite in a `MeterBinder` implementation. +By default, metrics from all `MeterBinder` beans will be automatically bound to the Spring-managed `MeterRegistry`. + [[production-ready-metrics-per-meter-properties]] === Customizing individual metrics -If you need to apply customizations to specific `Meter` instances you can use the -`io.micrometer.core.instrument.config.MeterFilter` interface. By default, all -`MeterFilter` beans will be automatically applied to the micrometer -`MeterRegistry.Config`. +If you need to apply customizations to specific `Meter` instances you can use the `io.micrometer.core.instrument.config.MeterFilter` interface. +By default, all `MeterFilter` beans will be automatically applied to the micrometer `MeterRegistry.Config`. -For example, if you want to rename the `mytag.region` tag to `mytag.area` for -all meter IDs beginning with `com.example`, you can do the following: +For example, if you want to rename the `mytag.region` tag to `mytag.area` for all meter IDs beginning with `com.example`, you can do the following: [source,java,indent=0] ---- include::{code-examples}/actuate/metrics/MetricsFilterBeanExample.java[tag=configuration] ---- + + [[production-ready-metrics-common-tags]] ==== Common tags -Common tags are generally used for dimensional drill-down on the operating environment like -host, instance, region, stack, etc. Commons tags are applied to all meters and can be -configured as shown in the following example: +Common tags are generally used for dimensional drill-down on the operating environment like host, instance, region, stack, etc. +Commons tags are applied to all meters and can be configured as shown in the following example: [source,properties,indent=0] ---- @@ -2107,20 +1879,17 @@ configured as shown in the following example: management.metrics.tags.stack=prod ---- -The example above adds `region` and `stack` tags to all meters with a value of -`us-east-1` and `prod` respectively. +The example above adds `region` and `stack` tags to all meters with a value of `us-east-1` and `prod` respectively. -NOTE: The order of common tags is important if you are using Graphite. As the order of -common tags cannot be guaranteed using this approach, Graphite users are advised to define -a custom `MeterFilter` instead. +NOTE: The order of common tags is important if you are using Graphite. +As the order of common tags cannot be guaranteed using this approach, Graphite users are advised to define a custom `MeterFilter` instead. ==== Per-meter properties -In addition to `MeterFilter` beans, it's also possible to apply a limited set of -customization on a per-meter basis using properties. Per-meter customizations apply to -any all meter IDs that start with the given name. For example, the following will disable -any meters that have an ID starting with `example.remote` +In addition to `MeterFilter` beans, it's also possible to apply a limited set of customization on a per-meter basis using properties. +Per-meter customizations apply to any all meter IDs that start with the given name. +For example, the following will disable any meters that have an ID starting with `example.remote` [source,properties,indent=0] ---- @@ -2137,11 +1906,9 @@ The following properties allow per-meter customization: | Whether to deny meters from emitting any metrics. | `management.metrics.distribution.percentiles-histogram` -| Whether to publish a histogram suitable for computing aggregable (across dimension) -percentile approximations. +| Whether to publish a histogram suitable for computing aggregable (across dimension) percentile approximations. -| `management.metrics.distribution.minimum-expected-value`, - `management.metrics.distribution.maximum-expected-value` +| `management.metrics.distribution.minimum-expected-value`, `management.metrics.distribution.maximum-expected-value` | Publish less histogram buckets by clamping the range of expected values. | `management.metrics.distribution.percentiles` @@ -2149,97 +1916,72 @@ percentile approximations. | `management.metrics.distribution.sla` | Publish a cumulative histogram with buckets defined by your SLAs. - |=== -For more details on concepts behind `percentiles-histogram`, `percentiles` and `sla` -refer to the {micrometer-concepts-documentation}#_histograms_and_percentiles["Histograms -and percentiles" section] of the micrometer documentation. +For more details on concepts behind `percentiles-histogram`, `percentiles` and `sla` refer to the {micrometer-concepts-documentation}#_histograms_and_percentiles["Histograms and percentiles" section] of the micrometer documentation. [[production-ready-metrics-endpoint]] === Metrics endpoint -Spring Boot provides a `metrics` endpoint that can be used diagnostically to examine the -metrics collected by an application. The endpoint is not available by default and must be -exposed, see <> for more -details. +Spring Boot provides a `metrics` endpoint that can be used diagnostically to examine the metrics collected by an application. +The endpoint is not available by default and must be exposed, see <> for more details. -Navigating to `/actuator/metrics` displays a list of available meter names. You can drill -down to view information about a particular meter by providing its name as a selector, -e.g. `/actuator/metrics/jvm.memory.max`. +Navigating to `/actuator/metrics` displays a list of available meter names. +You can drill down to view information about a particular meter by providing its name as a selector, e.g. `/actuator/metrics/jvm.memory.max`. [TIP] ==== -The name you use here should match the name used in the code, not the name after it has -been naming-convention normalized for a monitoring system it is shipped to. In other -words, if `jvm.memory.max` appears as `jvm_memory_max` in Prometheus because of its snake -case naming convention, you should still use `jvm.memory.max` as the selector when -inspecting the meter in the `metrics` endpoint. +The name you use here should match the name used in the code, not the name after it has been naming-convention normalized for a monitoring system it is shipped to. +In other words, if `jvm.memory.max` appears as `jvm_memory_max` in Prometheus because of its snake case naming convention, you should still use `jvm.memory.max` as the selector when inspecting the meter in the `metrics` endpoint. ==== -You can also add any number of `tag=KEY:VALUE` query parameters to the end of the URL to -dimensionally drill down on a meter, e.g. -`/actuator/metrics/jvm.memory.max?tag=area:nonheap`. +You can also add any number of `tag=KEY:VALUE` query parameters to the end of the URL to dimensionally drill down on a meter, e.g. `/actuator/metrics/jvm.memory.max?tag=area:nonheap`. [TIP] ==== -The reported measurements are the _sum_ of the statistics of all meters matching the meter -name and any tags that have been applied. So in the example above, the returned "Value" -statistic is the sum of the maximum memory footprints of "Code Cache", -"Compressed Class Space", and "Metaspace" areas of the heap. If you just wanted to see the -maximum size for the "Metaspace", you could add an additional `tag=id:Metaspace`, i.e. -`/actuator/metrics/jvm.memory.max?tag=area:nonheap&tag=id:Metaspace`. +The reported measurements are the _sum_ of the statistics of all meters matching the meter name and any tags that have been applied. +So in the example above, the returned "Value" statistic is the sum of the maximum memory footprints of "Code Cache", "Compressed Class Space", and "Metaspace" areas of the heap. +If you just wanted to see the maximum size for the "Metaspace", you could add an additional `tag=id:Metaspace`, i.e. `/actuator/metrics/jvm.memory.max?tag=area:nonheap&tag=id:Metaspace`. ==== [[production-ready-auditing]] == Auditing -Once Spring Security is in play, Spring Boot Actuator has a flexible audit framework that -publishes events (by default, "`authentication success`", "`failure`" and -"`access denied`" exceptions). This feature can be very useful for reporting and for -implementing a lock-out policy based on authentication failures. To customize published -security events, you can provide your own implementations of -`AbstractAuthenticationAuditListener` and `AbstractAuthorizationAuditListener`. +Once Spring Security is in play, Spring Boot Actuator has a flexible audit framework that publishes events (by default, "`authentication success`", "`failure`" and "`access denied`" exceptions). +This feature can be very useful for reporting and for implementing a lock-out policy based on authentication failures. +To customize published security events, you can provide your own implementations of `AbstractAuthenticationAuditListener` and `AbstractAuthorizationAuditListener`. -You can also use the audit services for your own business events. To do so, either inject -the existing `AuditEventRepository` into your own components and use that directly or -publish an `AuditApplicationEvent` with the Spring `ApplicationEventPublisher` (by -implementing `ApplicationEventPublisherAware`). +You can also use the audit services for your own business events. +To do so, either inject the existing `AuditEventRepository` into your own components and use that directly or publish an `AuditApplicationEvent` with the Spring `ApplicationEventPublisher` (by implementing `ApplicationEventPublisherAware`). [[production-ready-http-tracing]] == HTTP Tracing -Tracing is automatically enabled for all HTTP requests. You can view the `httptrace` -endpoint and obtain basic information about the last 100 request-response exchanges. +Tracing is automatically enabled for all HTTP requests. +You can view the `httptrace` endpoint and obtain basic information about the last 100 request-response exchanges. [[production-ready-http-tracing-custom]] === Custom HTTP tracing -To customize the items that are included in each trace, use the -`management.trace.http.include` configuration property. For advanced customization, -consider registering your own `HttpExchangeTracer` implementation. +To customize the items that are included in each trace, use the `management.trace.http.include` configuration property. +For advanced customization, consider registering your own `HttpExchangeTracer` implementation. -By default, an `InMemoryHttpTraceRepository` that stores traces for the last 100 -request-response exchanges is used. If you need to expand the capacity, you can define -your own instance of the `InMemoryHttpTraceRepository` bean. You can also create your own -alternative `HttpTraceRepository` implementation. +By default, an `InMemoryHttpTraceRepository` that stores traces for the last 100 request-response exchanges is used. +If you need to expand the capacity, you can define your own instance of the `InMemoryHttpTraceRepository` bean. +You can also create your own alternative `HttpTraceRepository` implementation. [[production-ready-process-monitoring]] == Process Monitoring -In the `spring-boot` module, you can find two classes to create files that are often -useful for process monitoring: +In the `spring-boot` module, you can find two classes to create files that are often useful for process monitoring: -* `ApplicationPidFileWriter` creates a file containing the application PID (by default, -in the application directory with a file name of `application.pid`). -* `WebServerPortFileWriter` creates a file (or files) containing the ports of the -running web server (by default, in the application directory with a file name of -`application.port`). +* `ApplicationPidFileWriter` creates a file containing the application PID (by default, in the application directory with a file name of `application.pid`). +* `WebServerPortFileWriter` creates a file (or files) containing the ports of the running web server (by default, in the application directory with a file name of `application.port`). By default, these writers are not activated, but you can enable: @@ -2250,8 +1992,7 @@ By default, these writers are not activated, but you can enable: [[production-ready-process-monitoring-configuration]] === Extending Configuration -In the `META-INF/spring.factories` file, you can activate the listener(s) that writes a -PID file, as shown in the following example: +In the `META-INF/spring.factories` file, you can activate the listener(s) that writes a PID file, as shown in the following example: [indent=0] ---- @@ -2264,22 +2005,18 @@ PID file, as shown in the following example: [[production-ready-process-monitoring-programmatically]] === Programmatically -You can also activate a listener by invoking the `SpringApplication.addListeners(...)` -method and passing the appropriate `Writer` object. This method also lets you customize -the file name and path in the `Writer` constructor. +You can also activate a listener by invoking the `SpringApplication.addListeners(...)` method and passing the appropriate `Writer` object. +This method also lets you customize the file name and path in the `Writer` constructor. [[production-ready-cloudfoundry]] == Cloud Foundry Support -Spring Boot's actuator module includes additional support that is activated when you -deploy to a compatible Cloud Foundry instance. The `/cloudfoundryapplication` path -provides an alternative secured route to all `@Endpoint` beans. +Spring Boot's actuator module includes additional support that is activated when you deploy to a compatible Cloud Foundry instance. +The `/cloudfoundryapplication` path provides an alternative secured route to all `@Endpoint` beans. -The extended support lets Cloud Foundry management UIs (such as the web application that -you can use to view deployed applications) be augmented with Spring Boot actuator -information. For example, an application status page may include full health information -instead of the typical "`running`" or "`stopped`" status. +The extended support lets Cloud Foundry management UIs (such as the web application that you can use to view deployed applications) be augmented with Spring Boot actuator information. +For example, an application status page may include full health information instead of the typical "`running`" or "`stopped`" status. NOTE: The `/cloudfoundryapplication` path is not directly accessible to regular users. In order to use the endpoint, a valid UAA token must be passed with the request. @@ -2288,8 +2025,7 @@ In order to use the endpoint, a valid UAA token must be passed with the request. [[production-ready-cloudfoundry-disable]] === Disabling Extended Cloud Foundry Actuator Support -If you want to fully disable the `/cloudfoundryapplication` endpoints, you can add the -following setting to your `application.properties` file: +If you want to fully disable the `/cloudfoundryapplication` endpoints, you can add the following setting to your `application.properties` file: .application.properties @@ -2302,9 +2038,8 @@ following setting to your `application.properties` file: [[production-ready-cloudfoundry-ssl]] === Cloud Foundry Self-signed Certificates -By default, the security verification for `/cloudfoundryapplication` endpoints makes SSL -calls to various Cloud Foundry services. If your Cloud Foundry UAA or Cloud Controller -services use self-signed certificates, you need to set the following property: +By default, the security verification for `/cloudfoundryapplication` endpoints makes SSL calls to various Cloud Foundry services. +If your Cloud Foundry UAA or Cloud Controller services use self-signed certificates, you need to set the following property: .application.properties [source,properties,indent=0] @@ -2315,16 +2050,11 @@ services use self-signed certificates, you need to set the following property: === Custom context path +If the server's context-path has been configured to anything other than `/`, the Cloud Foundry endpoints will not be available at the root of the application. +For example, if `server.servlet.context-path=/app`, Cloud Foundry endpoints will be available at `/app/cloudfoundryapplication/*`. -If the server's context-path has been configured to anything other than `/`, the Cloud -Foundry endpoints will not be available at the root of the application. For example, if -`server.servlet.context-path=/app`, Cloud Foundry endpoints will be available at -`/app/cloudfoundryapplication/*`. - -If you expect the Cloud Foundry endpoints to always be available at -`/cloudfoundryapplication/*`, regardless of the server's context-path, you will need to -explicitly configure that in your application. The configuration will differ depending on -the web server in use. For Tomcat, the following configuration can be added: +If you expect the Cloud Foundry endpoints to always be available at `/cloudfoundryapplication/*`, regardless of the server's context-path, you will need to explicitly configure that in your application. +The configuration will differ depending on the web server in use. For Tomcat, the following configuration can be added: [source,java,indent=0] ---- @@ -2335,10 +2065,7 @@ include::{code-examples}/cloudfoundry/CloudFoundryCustomContextPathExample.java[ [[production-ready-whats-next]] == What to Read Next -If you want to explore some of the concepts discussed in this chapter, you can take a -look at the actuator {github-code}/spring-boot-samples[sample applications]. You also -might want to read about graphing tools such as https://graphite.wikidot.com/[Graphite]. +If you want to explore some of the concepts discussed in this chapter, you can take a look at the actuator {github-code}/spring-boot-samples[sample applications]. +You also might want to read about graphing tools such as https://graphite.wikidot.com/[Graphite]. -Otherwise, you can continue on, to read about <> or jump ahead for some in-depth information about Spring Boot's -_<>_. +Otherwise, you can continue on, to read about <> or jump ahead for some in-depth information about Spring Boot's _<>_. diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-cli.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-cli.adoc index cf24b7dce6d..82bf51c9456 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-cli.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-cli.adoc @@ -3,28 +3,24 @@ [partintro] -- -The Spring Boot CLI is a command line tool that you can use if you want to quickly develop -a Spring application. It lets you run Groovy scripts, which means that you have a familiar -Java-like syntax without so much boilerplate code. You can also bootstrap a new project or -write your own command for it. +The Spring Boot CLI is a command line tool that you can use if you want to quickly develop a Spring application. +It lets you run Groovy scripts, which means that you have a familiar Java-like syntax without so much boilerplate code. +You can also bootstrap a new project or write your own command for it. -- [[cli-installation]] == Installing the CLI -The Spring Boot CLI (Command-Line Interface) can be installed manually by using SDKMAN! -(the SDK Manager) or by using Homebrew or MacPorts if you are an OSX user. See -_<>_ in the "`Getting started`" -section for comprehensive installation instructions. +The Spring Boot CLI (Command-Line Interface) can be installed manually by using SDKMAN! (the SDK Manager) or by using Homebrew or MacPorts if you are an OSX user. +See _<>_ in the "`Getting started`" section for comprehensive installation instructions. [[cli-using-the-cli]] == Using the CLI -Once you have installed the CLI, you can run it by typing `spring` and pressing Enter at -the command line. If you run `spring` without any arguments, a simple help screen is -displayed, as follows: +Once you have installed the CLI, you can run it by typing `spring` and pressing Enter at the command line. +If you run `spring` without any arguments, a simple help screen is displayed, as follows: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -40,8 +36,7 @@ displayed, as follows: _... more command help is shown here_ ---- -You can type `spring help` to get more details about any of the supported commands, as -shown in the following example: +You can type `spring help` to get more details about any of the supported commands, as shown in the following example: [indent=0] ---- @@ -65,8 +60,7 @@ shown in the following example: --watch Watch the specified file for changes ---- -The `version` command provides a quick way to check which version of Spring Boot you are -using, as follows: +The `version` command provides a quick way to check which version of Spring Boot you are using, as follows: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -78,8 +72,8 @@ using, as follows: [[cli-run]] === Running Applications with the CLI -You can compile and run Groovy source code by using the `run` command. The Spring Boot CLI -is completely self-contained, so you do not need any external Groovy installation. +You can compile and run Groovy source code by using the `run` command. +The Spring Boot CLI is completely self-contained, so you do not need any external Groovy installation. The following example shows a "`hello world`" web application written in Groovy: @@ -104,122 +98,108 @@ To compile and run the application, type the following command: $ spring run hello.groovy ---- -To pass command-line arguments to the application, use `--` to separate the commands -from the "`spring`" command arguments, as shown in the following example: +To pass command-line arguments to the application, use `--` to separate the commands from the "`spring`" command arguments, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- $ spring run hello.groovy -- --server.port=9000 ---- -To set JVM command line arguments, you can use the `JAVA_OPTS` environment variable, as -shown in the following example: +To set JVM command line arguments, you can use the `JAVA_OPTS` environment variable, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- $ JAVA_OPTS=-Xmx1024m spring run hello.groovy ---- -NOTE: When setting `JAVA_OPTS` on Microsoft Windows, make sure to quote the entire -instruction, such as `set "JAVA_OPTS=-Xms256m -Xmx2048m"`. Doing so ensures the values -are properly passed to the process. +NOTE: When setting `JAVA_OPTS` on Microsoft Windows, make sure to quote the entire instruction, such as `set "JAVA_OPTS=-Xms256m -Xmx2048m"`. +Doing so ensures the values are properly passed to the process. + + [[cli-deduced-grab-annotations]] ==== Deduced "`grab`" Dependencies -Standard Groovy includes a `@Grab` annotation, which lets you declare dependencies on -third-party libraries. This useful technique lets Groovy download jars in the same way as -Maven or Gradle would but without requiring you to use a build tool. +Standard Groovy includes a `@Grab` annotation, which lets you declare dependencies on third-party libraries. +This useful technique lets Groovy download jars in the same way as Maven or Gradle would but without requiring you to use a build tool. -Spring Boot extends this technique further and tries to deduce which libraries to "`grab`" -based on your code. For example, since the `WebApplication` code shown previously uses -`@RestController` annotations, Spring Boot grabs "Tomcat" and "Spring MVC". +Spring Boot extends this technique further and tries to deduce which libraries to "`grab`" based on your code. +For example, since the `WebApplication` code shown previously uses `@RestController` annotations, Spring Boot grabs "Tomcat" and "Spring MVC". The following items are used as "`grab hints`": |=== | Items | Grabs -|`JdbcTemplate`, `NamedParameterJdbcTemplate`, `DataSource` -|JDBC Application. +| `JdbcTemplate`, `NamedParameterJdbcTemplate`, `DataSource` +| JDBC Application. -|`@EnableJms` -|JMS Application. +| `@EnableJms` +| JMS Application. -|`@EnableCaching` -|Caching abstraction. +| `@EnableCaching` +| Caching abstraction. -|`@Test` -|JUnit. +| `@Test` +| JUnit. -|`@EnableRabbit` -|RabbitMQ. +| `@EnableRabbit` +| RabbitMQ. -|extends `Specification` -|Spock test. +| extends `Specification` +| Spock test. -|`@EnableBatchProcessing` -|Spring Batch. +| `@EnableBatchProcessing` +| Spring Batch. -|`@MessageEndpoint` `@EnableIntegration` -|Spring Integration. +| `@MessageEndpoint` `@EnableIntegration` +| Spring Integration. -|`@Controller` `@RestController` `@EnableWebMvc` -|Spring MVC + Embedded Tomcat. +| `@Controller` `@RestController` `@EnableWebMvc` +| Spring MVC + Embedded Tomcat. -|`@EnableWebSecurity` -|Spring Security. +| `@EnableWebSecurity` +| Spring Security. -|`@EnableTransactionManagement` -|Spring Transaction Management. +| `@EnableTransactionManagement` +| Spring Transaction Management. |=== -TIP: See subclasses of -{sc-spring-boot-cli}/compiler/CompilerAutoConfiguration.{sc-ext}[`CompilerAutoConfiguration`] -in the Spring Boot CLI source code to understand exactly how customizations are applied. +TIP: See subclasses of {sc-spring-boot-cli}/compiler/CompilerAutoConfiguration.{sc-ext}[`CompilerAutoConfiguration`] in the Spring Boot CLI source code to understand exactly how customizations are applied. [[cli-default-grab-deduced-coordinates]] ==== Deduced "`grab`" Coordinates -Spring Boot extends Groovy's standard `@Grab` support by letting you specify a dependency -without a group or version (for example, `@Grab('freemarker')`). Doing so consults Spring -Boot's default dependency metadata to deduce the artifact's group and version. +Spring Boot extends Groovy's standard `@Grab` support by letting you specify a dependency without a group or version (for example, `@Grab('freemarker')`). +Doing so consults Spring Boot's default dependency metadata to deduce the artifact's group and version. -NOTE: The default metadata is tied to the version of the CLI that you use. it changes only -when you move to a new version of the CLI, putting you in control of when the versions of -your dependencies may change. A table showing the dependencies and their versions that are -included in the default metadata can be found in the <>. +NOTE: The default metadata is tied to the version of the CLI that you use. it changes only when you move to a new version of the CLI, putting you in control of when the versions of your dependencies may change. +A table showing the dependencies and their versions that are included in the default metadata can be found in the <>. [[cli-default-import-statements]] ==== Default Import Statements -To help reduce the size of your Groovy code, several `import` statements are automatically -included. Notice how the preceding example refers to `@Component`, `@RestController`, and -`@RequestMapping` without needing to use fully-qualified names or `import` statements. +To help reduce the size of your Groovy code, several `import` statements are automatically included. +Notice how the preceding example refers to `@Component`, `@RestController`, and `@RequestMapping` without needing to use fully-qualified names or `import` statements. -TIP: Many Spring annotations work without using `import` statements. Try running your -application to see what fails before adding imports. +TIP: Many Spring annotations work without using `import` statements. +Try running your application to see what fails before adding imports. [[cli-automatic-main-method]] ==== Automatic Main Method -Unlike the equivalent Java application, you do not need to include a -`public static void main(String[] args)` method with your `Groovy` scripts. A -`SpringApplication` is automatically created, with your compiled code acting as the -`source`. +Unlike the equivalent Java application, you do not need to include a `public static void main(String[] args)` method with your `Groovy` scripts. +A `SpringApplication` is automatically created, with your compiled code acting as the `source`. [[cli-default-grab-deduced-coordinates-custom-dependency-management]] ==== Custom Dependency Management -By default, the CLI uses the dependency management declared in `spring-boot-dependencies` -when resolving `@Grab` dependencies. Additional dependency management, which overrides -the default dependency management, can be configured by using the -`@DependencyManagementBom` annotation. The annotation's value should specify the -coordinates (`groupId:artifactId:version`) of one or more Maven BOMs. +By default, the CLI uses the dependency management declared in `spring-boot-dependencies` when resolving `@Grab` dependencies. +Additional dependency management, which overrides the default dependency management, can be configured by using the `@DependencyManagementBom` annotation. +The annotation's value should specify the coordinates (`groupId:artifactId:version`) of one or more Maven BOMs. For example, consider the following declaration: @@ -228,11 +208,9 @@ For example, consider the following declaration: @DependencyManagementBom("com.example.custom-bom:1.0.0") ---- -The preceding declaration picks up `custom-bom-1.0.0.pom` in a Maven repository under -`com/example/custom-versions/1.0.0/`. +The preceding declaration picks up `custom-bom-1.0.0.pom` in a Maven repository under `com/example/custom-versions/1.0.0/`. -When you specify multiple BOMs, they are applied in the order in which you declare them, -as shown in the following example: +When you specify multiple BOMs, they are applied in the order in which you declare them, as shown in the following example: [source,java,indent=0] ---- @@ -240,15 +218,11 @@ as shown in the following example: "com.example.another-bom:1.0.0"]) ---- -The preceding example indicates that the dependency management in `another-bom` overrides -the dependency management in `custom-bom`. +The preceding example indicates that the dependency management in `another-bom` overrides the dependency management in `custom-bom`. -You can use `@DependencyManagementBom` anywhere that you can use `@Grab`. However, to -ensure consistent ordering of the dependency management, you can use -`@DependencyManagementBom` at most once in your application. A useful source of dependency -management (which is a superset of Spring Boot's dependency management) is the -https://platform.spring.io/[Spring IO Platform], which you might include with the following -line: +You can use `@DependencyManagementBom` anywhere that you can use `@Grab`. +However, to ensure consistent ordering of the dependency management, you can use `@DependencyManagementBom` at most once in your application. +A useful source of dependency management (which is a superset of Spring Boot's dependency management) is the https://platform.spring.io/[Spring IO Platform], which you might include with the following line: [source,java,indent=0] ---- @@ -258,8 +232,8 @@ line: [[cli-multiple-source-files]] === Applications with Multiple Source Files -You can use "`shell globbing`" with all commands that accept file input. Doing so lets -you use multiple files from a single directory, as shown in the following example: +You can use "`shell globbing`" with all commands that accept file input. +Doing so lets you use multiple files from a single directory, as shown in the following example: [indent=0] ---- @@ -270,20 +244,18 @@ you use multiple files from a single directory, as shown in the following exampl [[cli-jar]] === Packaging Your Application -You can use the `jar` command to package your application into a self-contained executable -jar file, as shown in the following example: +You can use the `jar` command to package your application into a self-contained executable jar file, as shown in the following example: [indent=0] ---- $ spring jar my-app.jar *.groovy ---- -The resulting jar contains the classes produced by compiling the application and all of -the application's dependencies so that it can then be run by using `java -jar`. The jar -file also contains entries from the application's classpath. You can add and remove -explicit paths to the jar by using `--include` and `--exclude`. Both are comma-separated, -and both accept prefixes, in the form of "`+`" and "`-`", to signify that they should be -removed from the defaults. The default includes are as follows: +The resulting jar contains the classes produced by compiling the application and all of the application's dependencies so that it can then be run by using `java -jar`. +The jar file also contains entries from the application's classpath. +You can add and remove explicit paths to the jar by using `--include` and `--exclude`. +Both are comma-separated, and both accept prefixes, in the form of "`+`" and "`-`", to signify that they should be removed from the defaults. +The default includes are as follows: [indent=0] ---- @@ -303,8 +275,7 @@ Type `spring help jar` on the command line for more information. [[cli-init]] === Initialize a New Project -The `init` command lets you create a new project by using https://start.spring.io without -leaving the shell, as shown in the following example: +The `init` command lets you create a new project by using https://start.spring.io without leaving the shell, as shown in the following example: [indent=0] ---- @@ -313,9 +284,8 @@ leaving the shell, as shown in the following example: Project extracted to '/Users/developer/example/my-project' ---- -The preceding example creates a `my-project` directory with a Maven-based project that -uses `spring-boot-starter-web` and `spring-boot-starter-data-jpa`. You can list the -capabilities of the service by using the `--list` flag, as shown in the following example: +The preceding example creates a `my-project` directory with a Maven-based project that uses `spring-boot-starter-web` and `spring-boot-starter-data-jpa`. +You can list the capabilities of the service by using the `--list` flag, as shown in the following example: [indent=0] ---- @@ -342,9 +312,9 @@ capabilities of the service by using the `--list` flag, as shown in the followin ... ---- -The `init` command supports many options. See the `help` output for more details. For -instance, the following command creates a Gradle project that uses Java 8 and `war` -packaging: +The `init` command supports many options. +See the `help` output for more details. +For instance, the following command creates a Gradle project that uses Java 8 and `war` packaging: [indent=0] ---- @@ -357,9 +327,8 @@ packaging: [[cli-shell]] === Using the Embedded Shell -Spring Boot includes command-line completion scripts for the BASH and zsh shells. If you -do not use either of these shells (perhaps you are a Windows user), you can use the -`shell` command to launch an integrated shell, as shown in the following example: +Spring Boot includes command-line completion scripts for the BASH and zsh shells. +If you do not use either of these shells (perhaps you are a Windows user), you can use the `shell` command to launch an integrated shell, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -376,40 +345,34 @@ From inside the embedded shell, you can run other commands directly: Spring CLI v{spring-boot-version} ---- -The embedded shell supports ANSI color output as well as `tab` completion. If you need to -run a native command, you can use the `!` prefix. To exit the embedded shell, press -`ctrl-c`. +The embedded shell supports ANSI color output as well as `tab` completion. +If you need to run a native command, you can use the `!` prefix. +To exit the embedded shell, press `ctrl-c`. [[cli-install-uninstall]] === Adding Extensions to the CLI -You can add extensions to the CLI by using the `install` command. The command takes one -or more sets of artifact coordinates in the format `group:artifact:version`, as shown in -the following example: +You can add extensions to the CLI by using the `install` command. +The command takes one or more sets of artifact coordinates in the format `group:artifact:version`, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- $ spring install com.example:spring-boot-cli-extension:1.0.0.RELEASE ---- -In addition to installing the artifacts identified by the coordinates you supply, all of -the artifacts' dependencies are also installed. +In addition to installing the artifacts identified by the coordinates you supply, all of the artifacts' dependencies are also installed. -To uninstall a dependency, use the `uninstall` command. As with the `install` command, it -takes one or more sets of artifact coordinates in the format of `group:artifact:version`, -as shown in the following example: +To uninstall a dependency, use the `uninstall` command. As with the `install` command, it takes one or more sets of artifact coordinates in the format of `group:artifact:version`, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- $ spring uninstall com.example:spring-boot-cli-extension:1.0.0.RELEASE ---- -It uninstalls the artifacts identified by the coordinates you supply and their -dependencies. +It uninstalls the artifacts identified by the coordinates you supply and their dependencies. -To uninstall all additional dependencies, you can use the `--all` option, as shown in the -following example: +To uninstall all additional dependencies, you can use the `--all` option, as shown in the following example: [indent=0,subs="verbatim,quotes,attributes"] ---- @@ -420,10 +383,8 @@ following example: [[cli-groovy-beans-dsl]] == Developing Applications with the Groovy Beans DSL -Spring Framework 4.0 has native support for a `beans{}` "`DSL`" (borrowed from -https://grails.org/[Grails]), and you can embed bean definitions in your Groovy application -scripts by using the same format. This is sometimes a good way to include external -features like middleware declarations, as shown in the following example: +Spring Framework 4.0 has native support for a `beans{}` "`DSL`" (borrowed from https://grails.org/[Grails]), and you can embed bean definitions in your Groovy application scripts by using the same format. +This is sometimes a good way to include external features like middleware declarations, as shown in the following example: [source,groovy,indent=0] ---- @@ -449,16 +410,15 @@ features like middleware declarations, as shown in the following example: } ---- -You can mix class declarations with `beans{}` in the same file as long as they stay at -the top level, or, if you prefer, you can put the beans DSL in a separate file. +You can mix class declarations with `beans{}` in the same file as long as they stay at the top level, or, if you prefer, you can put the beans DSL in a separate file. [[cli-maven-settings]] == Configuring the CLI with `settings.xml` -The Spring Boot CLI uses Aether, Maven's dependency resolution engine, to resolve -dependencies. The CLI makes use of the Maven configuration found in `~/.m2/settings.xml` -to configure Aether. The following configuration settings are honored by the CLI: +The Spring Boot CLI uses Aether, Maven's dependency resolution engine, to resolve dependencies. +The CLI makes use of the Maven configuration found in `~/.m2/settings.xml` to configure Aether. +The following configuration settings are honored by the CLI: * Offline * Mirrors @@ -469,18 +429,14 @@ to configure Aether. The following configuration settings are honored by the CLI ** Repositories * Active profiles -See https://maven.apache.org/settings.html[Maven's settings documentation] for further -information. +See https://maven.apache.org/settings.html[Maven's settings documentation] for further information. [[cli-whats-next]] == What to Read Next -There are some {github-code}/spring-boot-project/spring-boot-cli/samples[sample groovy -scripts] available from the GitHub repository that you can use to try out the Spring Boot -CLI. There is also extensive Javadoc throughout the {sc-spring-boot-cli}[source code]. +There are some {github-code}/spring-boot-project/spring-boot-cli/samples[sample groovy scripts] available from the GitHub repository that you can use to try out the Spring Boot CLI. +There is also extensive Javadoc throughout the {sc-spring-boot-cli}[source code]. -If you find that you reach the limit of the CLI tool, you probably want to look at -converting your application to a full Gradle or Maven built "`Groovy project`". The -next section covers Spring Boot's "<>", which you can use with Gradle or Maven. +If you find that you reach the limit of the CLI tool, you probably want to look at converting your application to a full Gradle or Maven built "`Groovy project`". +The next section covers Spring Boot's "<>", which you can use with Gradle or Maven. diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc index a72a507b4e5..8b173be4b19 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc @@ -3,20 +3,17 @@ [partintro] -- -This section dives into the details of Spring Boot. Here you can learn about the key -features that you may want to use and customize. If you have not already done so, you -might want to read the "<>" and -"<>" sections, so that you have a good grounding of the -basics. +This section dives into the details of Spring Boot. +Here you can learn about the key features that you may want to use and customize. +If you have not already done so, you might want to read the "<>" and "<>" sections, so that you have a good grounding of the basics. -- [[boot-features-spring-application]] == SpringApplication -The `SpringApplication` class provides a convenient way to bootstrap a Spring application -that is started from a `main()` method. In many situations, you can delegate to the -static `SpringApplication.run` method, as shown in the following example: +The `SpringApplication` class provides a convenient way to bootstrap a Spring application that is started from a `main()` method. +In many situations, you can delegate to the static `SpringApplication.run` method, as shown in the following example: [source,java,indent=0] ---- @@ -37,24 +34,21 @@ When your application starts, you should see something similar to the following =========|_|==============|___/=/_/_/_/ :: Spring Boot :: v{spring-boot-version} -2013-07-31 00:08:16.117 INFO 56603 --- [ main] o.s.b.s.app.SampleApplication : Starting SampleApplication v0.1.0 on mycomputer with PID 56603 (/apps/myapp.jar started by pwebb) -2013-07-31 00:08:16.166 INFO 56603 --- [ main] ationConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@6e5a8246: startup date [Wed Jul 31 00:08:16 PDT 2013]; root of context hierarchy -2014-03-04 13:09:54.912 INFO 41370 --- [ main] .t.TomcatServletWebServerFactory : Server initialized with port: 8080 -2014-03-04 13:09:56.501 INFO 41370 --- [ main] o.s.b.s.app.SampleApplication : Started SampleApplication in 2.992 seconds (JVM running for 3.658) +2019-04-31 13:09:54.117 INFO 56603 --- [ main] o.s.b.s.app.SampleApplication : Starting SampleApplication v0.1.0 on mycomputer with PID 56603 (/apps/myapp.jar started by pwebb) +2019-04-31 13:09:54.166 INFO 56603 --- [ main] ationConfigServletWebServerApplicationContext : Refreshing org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext@6e5a8246: startup date [Wed Jul 31 00:08:16 PDT 2013]; root of context hierarchy +2019-04-01 13:09:56.912 INFO 41370 --- [ main] .t.TomcatServletWebServerFactory : Server initialized with port: 8080 +2019-04-01 13:09:57.501 INFO 41370 --- [ main] o.s.b.s.app.SampleApplication : Started SampleApplication in 2.992 seconds (JVM running for 3.658) ---- -By default, `INFO` logging messages are shown, including some relevant startup details, -such as the user that launched the application. If you need a log level other than `INFO`, -you can set it, as described in <>, +By default, `INFO` logging messages are shown, including some relevant startup details, such as the user that launched the application. +If you need a log level other than `INFO`, you can set it, as described in <>. [[boot-features-startup-failure]] === Startup Failure -If your application fails to start, registered `FailureAnalyzers` get a chance to provide -a dedicated error message and a concrete action to fix the problem. For instance, if you -start a web application on port `8080` and that port is already in use, you should see -something similar to the following message: +If your application fails to start, registered `FailureAnalyzers` get a chance to provide a dedicated error message and a concrete action to fix the problem. +For instance, if you start a web application on port `8080` and that port is already in use, you should see something similar to the following message: [indent=0] ---- @@ -71,17 +65,12 @@ something similar to the following message: Identify and stop the process that's listening on port 8080 or configure this application to listen on another port. ---- -NOTE: Spring Boot provides numerous `FailureAnalyzer` implementations, and you can -<>. +NOTE: Spring Boot provides numerous `FailureAnalyzer` implementations, and you can <>. -If no failure analyzers are able to handle the exception, you can still display the full -conditions report to better understand what went wrong. To do so, you need to -<> or -<> for -`org.springframework.boot.autoconfigure.logging.ConditionEvaluationReportLoggingListener`. +If no failure analyzers are able to handle the exception, you can still display the full conditions report to better understand what went wrong. +To do so, you need to <> or <> for `org.springframework.boot.autoconfigure.logging.ConditionEvaluationReportLoggingListener`. -For instance, if you are running your application by using `java -jar`, you can enable -the `debug` property as follows: +For instance, if you are running your application by using `java -jar`, you can enable the `debug` property as follows: [indent=0,subs="attributes"] ---- @@ -92,12 +81,10 @@ the `debug` property as follows: [[boot-features-banner]] === Customizing the Banner -The banner that is printed on start up can be changed by adding a `banner.txt` file to -your classpath or by setting the `spring.banner.location` property to the location of such -a file. If the file has an encoding other than UTF-8, you can set `spring.banner.charset`. -In addition to a text file, you can also add a `banner.gif`, `banner.jpg`, or `banner.png` -image file to your classpath or set the `spring.banner.image.location` property. Images -are converted into an ASCII art representation and printed above any text banner. +The banner that is printed on start up can be changed by adding a `banner.txt` file to your classpath or by setting the `spring.banner.location` property to the location of such a file. +If the file has an encoding other than UTF-8, you can set `spring.banner.charset`. +In addition to a text file, you can also add a `banner.gif`, `banner.jpg`, or `banner.png` image file to your classpath or set the `spring.banner.image.location` property. +Images are converted into an ASCII art representation and printed above any text banner. Inside your `banner.txt` file, you can use any of the following placeholders: @@ -105,45 +92,39 @@ Inside your `banner.txt` file, you can use any of the following placeholders: |=== | Variable | Description -|`${application.version}` -|The version number of your application, as declared in `MANIFEST.MF`. For example, -`Implementation-Version: 1.0` is printed as `1.0`. +| `${application.version}` +| The version number of your application, as declared in `MANIFEST.MF`. + For example, `Implementation-Version: 1.0` is printed as `1.0`. -|`${application.formatted-version}` -|The version number of your application, as declared in `MANIFEST.MF` and formatted for -display (surrounded with brackets and prefixed with `v`). For example `(v1.0)`. +| `${application.formatted-version}` +| The version number of your application, as declared in `MANIFEST.MF` and formatted for display (surrounded with brackets and prefixed with `v`). For example `(v1.0)`. -|`${spring-boot.version}` -|The Spring Boot version that you are using. For example `{spring-boot-version}`. +| `${spring-boot.version}` +| The Spring Boot version that you are using. For example `{spring-boot-version}`. -|`${spring-boot.formatted-version}` -|The Spring Boot version that you are using, formatted for display (surrounded with -brackets and prefixed with `v`). For example `(v{spring-boot-version})`. +| `${spring-boot.formatted-version}` +| The Spring Boot version that you are using, formatted for display (surrounded with brackets and prefixed with `v`). + For example `(v{spring-boot-version})`. -|`${Ansi.NAME}` (or `${AnsiColor.NAME}`, `${AnsiBackground.NAME}`, `${AnsiStyle.NAME}`) -|Where `NAME` is the name of an ANSI escape code. See -{sc-spring-boot}/ansi/AnsiPropertySource.{sc-ext}[`AnsiPropertySource`] for details. +| `${Ansi.NAME}` (or `${AnsiColor.NAME}`, `${AnsiBackground.NAME}`, `${AnsiStyle.NAME}`) +| Where `NAME` is the name of an ANSI escape code. + See {sc-spring-boot}/ansi/AnsiPropertySource.{sc-ext}[`AnsiPropertySource`] for details. -|`${application.title}` -|The title of your application, as declared in `MANIFEST.MF`. For example -`Implementation-Title: MyApp` is printed as `MyApp`. +| `${application.title}` +| The title of your application, as declared in `MANIFEST.MF`. + For example `Implementation-Title: MyApp` is printed as `MyApp`. |=== -TIP: The `SpringApplication.setBanner(...)` method can be used if you want to generate -a banner programmatically. Use the `org.springframework.boot.Banner` interface and -implement your own `printBanner()` method. +TIP: The `SpringApplication.setBanner(...)` method can be used if you want to generate a banner programmatically. +Use the `org.springframework.boot.Banner` interface and implement your own `printBanner()` method. -You can also use the `spring.main.banner-mode` property to determine if the banner has -to be printed on `System.out` (`console`), sent to the configured logger (`log`), or not -produced at all (`off`). +You can also use the `spring.main.banner-mode` property to determine if the banner has to be printed on `System.out` (`console`), sent to the configured logger (`log`), or not produced at all (`off`). -The printed banner is registered as a singleton bean under the following name: -`springBootBanner`. +The printed banner is registered as a singleton bean under the following name: `springBootBanner`. [NOTE] ==== -YAML maps `off` to `false`, so be sure to add quotes if you want to disable the banner in -your application, as shown in the following example: +YAML maps `off` to `false`, so be sure to add quotes if you want to disable the banner in your application, as shown in the following example: [source,yaml,indent=0] ---- @@ -153,10 +134,12 @@ your application, as shown in the following example: ---- ==== + + [[boot-features-customizing-spring-application]] === Customizing SpringApplication -If the `SpringApplication` defaults are not to your taste, you can instead create a local -instance and customize it. For example, to turn off the banner, you could write: +If the `SpringApplication` defaults are not to your taste, you can instead create a local instance and customize it. +For example, to turn off the banner, you could write: [source,java,indent=0] ---- @@ -167,58 +150,43 @@ instance and customize it. For example, to turn off the banner, you could write: } ---- -NOTE: The constructor arguments passed to `SpringApplication` are configuration sources -for Spring beans. In most cases, these are references to `@Configuration` classes, but -they could also be references to XML configuration or to packages that should be scanned. +NOTE: The constructor arguments passed to `SpringApplication` are configuration sources for Spring beans. +In most cases, these are references to `@Configuration` classes, but they could also be references to XML configuration or to packages that should be scanned. -It is also possible to configure the `SpringApplication` by using an -`application.properties` file. See _<>_ for details. +It is also possible to configure the `SpringApplication` by using an `application.properties` file. +See _<>_ for details. -For a complete list of the configuration options, see the -{dc-spring-boot}/SpringApplication.{dc-ext}[`SpringApplication` Javadoc]. +For a complete list of the configuration options, see the {dc-spring-boot}/SpringApplication.{dc-ext}[`SpringApplication` Javadoc]. [[boot-features-fluent-builder-api]] === Fluent Builder API -If you need to build an `ApplicationContext` hierarchy (multiple contexts with a -parent/child relationship) or if you prefer using a "`fluent`" builder API, you can -use the `SpringApplicationBuilder`. +If you need to build an `ApplicationContext` hierarchy (multiple contexts with a parent/child relationship) or if you prefer using a "`fluent`" builder API, you can use the `SpringApplicationBuilder`. -The `SpringApplicationBuilder` lets you chain together multiple method calls and includes -`parent` and `child` methods that let you create a hierarchy, as shown in the following -example: +The `SpringApplicationBuilder` lets you chain together multiple method calls and includes `parent` and `child` methods that let you create a hierarchy, as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/builder/SpringApplicationBuilderExample.java[tag=hierarchy] ---- -NOTE: There are some restrictions when creating an `ApplicationContext` hierarchy. For -example, Web components *must* be contained within the child context, and the same -`Environment` is used for both parent and child contexts. See the -{dc-spring-boot}/builder/SpringApplicationBuilder.{dc-ext}[`SpringApplicationBuilder` -Javadoc] for full details. +NOTE: There are some restrictions when creating an `ApplicationContext` hierarchy. +For example, Web components *must* be contained within the child context, and the same `Environment` is used for both parent and child contexts. +See the {dc-spring-boot}/builder/SpringApplicationBuilder.{dc-ext}[`SpringApplicationBuilder` Javadoc] for full details. [[boot-features-application-events-and-listeners]] === Application Events and Listeners -In addition to the usual Spring Framework events, such as -{spring-javadoc}/context/event/ContextRefreshedEvent.{dc-ext}[`ContextRefreshedEvent`], -a `SpringApplication` sends some additional application events. +In addition to the usual Spring Framework events, such as {spring-javadoc}/context/event/ContextRefreshedEvent.{dc-ext}[`ContextRefreshedEvent`], a `SpringApplication` sends some additional application events. [NOTE] ==== -Some events are actually triggered before the `ApplicationContext` is created, so you -cannot register a listener on those as a `@Bean`. You can register them with the -`SpringApplication.addListeners(...)` method or the -`SpringApplicationBuilder.listeners(...)` method. +Some events are actually triggered before the `ApplicationContext` is created, so you cannot register a listener on those as a `@Bean`. +You can register them with the `SpringApplication.addListeners(...)` method or the `SpringApplicationBuilder.listeners(...)` method. -If you want those listeners to be registered automatically, regardless of the way the -application is created, you can add a `META-INF/spring.factories` file to your project -and reference your listener(s) by using the -`org.springframework.context.ApplicationListener` key, as shown in the following example: +If you want those listeners to be registered automatically, regardless of the way the application is created, you can add a `META-INF/spring.factories` file to your project and reference your listener(s) by using the `org.springframework.context.ApplicationListener` key, as shown in the following example: [indent=0] ---- @@ -229,65 +197,48 @@ and reference your listener(s) by using the Application events are sent in the following order, as your application runs: -. An `ApplicationStartingEvent` is sent at the start of a run but before any processing, -except for the registration of listeners and initializers. -. An `ApplicationEnvironmentPreparedEvent` is sent when the `Environment` to be used in -the context is known but before the context is created. -. An `ApplicationPreparedEvent` is sent just before the refresh is started but after bean -definitions have been loaded. -. An `ApplicationStartedEvent` is sent after the context has been refreshed but before any -application and command-line runners have been called. -. An `ApplicationReadyEvent` is sent after any application and command-line runners have -been called. It indicates that the application is ready to service requests. +. An `ApplicationStartingEvent` is sent at the start of a run but before any processing, except for the registration of listeners and initializers. +. An `ApplicationEnvironmentPreparedEvent` is sent when the `Environment` to be used in the context is known but before the context is created. +. An `ApplicationPreparedEvent` is sent just before the refresh is started but after bean definitions have been loaded. +. An `ApplicationStartedEvent` is sent after the context has been refreshed but before any application and command-line runners have been called. +. An `ApplicationReadyEvent` is sent after any application and command-line runners have been called. + It indicates that the application is ready to service requests. . An `ApplicationFailedEvent` is sent if there is an exception on startup. -TIP: You often need not use application events, but it can be handy to know that they -exist. Internally, Spring Boot uses events to handle a variety of tasks. +TIP: You often need not use application events, but it can be handy to know that they exist. +Internally, Spring Boot uses events to handle a variety of tasks. -Application events are sent by using Spring Framework's event publishing mechanism. Part -of this mechanism ensures that an event published to the listeners in a child context is -also published to the listeners in any ancestor contexts. As a result of this, if your -application uses a hierarchy of `SpringApplication` instances, a listener may receive -multiple instances of the same type of application event. +Application events are sent by using Spring Framework's event publishing mechanism. +Part of this mechanism ensures that an event published to the listeners in a child context is also published to the listeners in any ancestor contexts. +As a result of this, if your application uses a hierarchy of `SpringApplication` instances, a listener may receive multiple instances of the same type of application event. -To allow your listener to distinguish between an event for its context and an event for -a descendant context, it should request that its application context is injected and then -compare the injected context with the context of the event. The context can be injected -by implementing `ApplicationContextAware` or, if the listener is a bean, by using -`@Autowired`. +To allow your listener to distinguish between an event for its context and an event for a descendant context, it should request that its application context is injected and then compare the injected context with the context of the event. +The context can be injected by implementing `ApplicationContextAware` or, if the listener is a bean, by using `@Autowired`. [[boot-features-web-environment]] === Web Environment -A `SpringApplication` attempts to create the right type of `ApplicationContext` on your -behalf. The algorithm used to determine a `WebApplicationType` is fairly simple: +A `SpringApplication` attempts to create the right type of `ApplicationContext` on your behalf. +The algorithm used to determine a `WebApplicationType` is fairly simple: -* If Spring MVC is present, an `AnnotationConfigServletWebServerApplicationContext` is -used -* If Spring MVC is not present and Spring WebFlux is present, an -`AnnotationConfigReactiveWebServerApplicationContext` is used +* If Spring MVC is present, an `AnnotationConfigServletWebServerApplicationContext` is used +* If Spring MVC is not present and Spring WebFlux is present, an `AnnotationConfigReactiveWebServerApplicationContext` is used * Otherwise, `AnnotationConfigApplicationContext` is used -This means that if you are using Spring MVC and the new `WebClient` from Spring WebFlux in -the same application, Spring MVC will be used by default. You can override that easily -by calling `setWebApplicationType(WebApplicationType)`. +This means that if you are using Spring MVC and the new `WebClient` from Spring WebFlux in the same application, Spring MVC will be used by default. +You can override that easily by calling `setWebApplicationType(WebApplicationType)`. -It is also possible to take complete control of the `ApplicationContext` type that is -used by calling `setApplicationContextClass(...)`. +It is also possible to take complete control of the `ApplicationContext` type that is used by calling `setApplicationContextClass(...)`. -TIP: It is often desirable to call `setWebApplicationType(WebApplicationType.NONE)` when -using `SpringApplication` within a JUnit test. +TIP: It is often desirable to call `setWebApplicationType(WebApplicationType.NONE)` when using `SpringApplication` within a JUnit test. [[boot-features-application-arguments]] === Accessing Application Arguments -If you need to access the application arguments that were passed to -`SpringApplication.run(...)`, you can inject a -`org.springframework.boot.ApplicationArguments` bean. The `ApplicationArguments` -interface provides access to both the raw `String[]` arguments as well as parsed `option` -and `non-option` arguments, as shown in the following example: +If you need to access the application arguments that were passed to `SpringApplication.run(...)`, you can inject a `org.springframework.boot.ApplicationArguments` bean. +The `ApplicationArguments` interface provides access to both the raw `String[]` arguments as well as parsed `option` and `non-option` arguments, as shown in the following example: [source,java,indent=0] ---- @@ -308,22 +259,18 @@ and `non-option` arguments, as shown in the following example: } ---- -TIP: Spring Boot also registers a `CommandLinePropertySource` with the Spring -`Environment`. This lets you also inject single application arguments by using the -`@Value` annotation. +TIP: Spring Boot also registers a `CommandLinePropertySource` with the Spring `Environment`. +This lets you also inject single application arguments by using the `@Value` annotation. [[boot-features-command-line-runner]] === Using the ApplicationRunner or CommandLineRunner -If you need to run some specific code once the `SpringApplication` has started, you can -implement the `ApplicationRunner` or `CommandLineRunner` interfaces. Both interfaces work -in the same way and offer a single `run` method, which is called just before -`SpringApplication.run(...)` completes. +If you need to run some specific code once the `SpringApplication` has started, you can implement the `ApplicationRunner` or `CommandLineRunner` interfaces. +Both interfaces work in the same way and offer a single `run` method, which is called just before `SpringApplication.run(...)` completes. -The `CommandLineRunner` interfaces provides access to application arguments as a simple -string array, whereas the `ApplicationRunner` uses the `ApplicationArguments` interface -discussed earlier. The following example shows a `CommandLineRunner` with a `run` method: +The `CommandLineRunner` interfaces provides access to application arguments as a simple string array, whereas the `ApplicationRunner` uses the `ApplicationArguments` interface discussed earlier. +The following example shows a `CommandLineRunner` with a `run` method: [source,java,indent=0] ---- @@ -340,98 +287,70 @@ discussed earlier. The following example shows a `CommandLineRunner` with a `run } ---- -If several `CommandLineRunner` or `ApplicationRunner` beans are defined that must be -called in a specific order, you can additionally implement the -`org.springframework.core.Ordered` interface or use the -`org.springframework.core.annotation.Order` annotation. +If several `CommandLineRunner` or `ApplicationRunner` beans are defined that must be called in a specific order, you can additionally implement the `org.springframework.core.Ordered` interface or use the `org.springframework.core.annotation.Order` annotation. [[boot-features-application-exit]] === Application Exit -Each `SpringApplication` registers a shutdown hook with the JVM to ensure that the -`ApplicationContext` closes gracefully on exit. All the standard Spring lifecycle -callbacks (such as the `DisposableBean` interface or the `@PreDestroy` annotation) can be -used. +Each `SpringApplication` registers a shutdown hook with the JVM to ensure that the `ApplicationContext` closes gracefully on exit. +All the standard Spring lifecycle callbacks (such as the `DisposableBean` interface or the `@PreDestroy` annotation) can be used. -In addition, beans may implement the `org.springframework.boot.ExitCodeGenerator` -interface if they wish to return a specific exit code when `SpringApplication.exit()` is -called. This exit code can then be passed to `System.exit()` to return it as a status -code, as shown in the following example: +In addition, beans may implement the `org.springframework.boot.ExitCodeGenerator` interface if they wish to return a specific exit code when `SpringApplication.exit()` is called. +This exit code can then be passed to `System.exit()` to return it as a status code, as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/ExitCodeApplication.java[tag=example] ---- -Also, the `ExitCodeGenerator` interface may be implemented by exceptions. When such an -exception is encountered, Spring Boot returns the exit code provided by the implemented -`getExitCode()` method. +Also, the `ExitCodeGenerator` interface may be implemented by exceptions. +When such an exception is encountered, Spring Boot returns the exit code provided by the implemented `getExitCode()` method. + [[boot-features-application-admin]] === Admin Features -It is possible to enable admin-related features for the application by specifying the -`spring.application.admin.enabled` property. This exposes the -{sc-spring-boot}/admin/SpringApplicationAdminMXBean.{sc-ext}[`SpringApplicationAdminMXBean`] -on the platform `MBeanServer`. You could use this feature to administer your Spring Boot -application remotely. This feature could also be useful for any service wrapper -implementation. +It is possible to enable admin-related features for the application by specifying the `spring.application.admin.enabled` property. +This exposes the {sc-spring-boot}/admin/SpringApplicationAdminMXBean.{sc-ext}[`SpringApplicationAdminMXBean`] on the platform `MBeanServer`. +You could use this feature to administer your Spring Boot application remotely. +This feature could also be useful for any service wrapper implementation. -TIP: If you want to know on which HTTP port the application is running, get the property -with a key of `local.server.port`. +TIP: If you want to know on which HTTP port the application is running, get the property with a key of `local.server.port`. -CAUTION: Take care when enabling this feature, as the MBean exposes a method to shutdown -the application. +CAUTION: Take care when enabling this feature, as the MBean exposes a method to shutdown the application. [[boot-features-external-config]] == Externalized Configuration -Spring Boot lets you externalize your configuration so that you can work with the same -application code in different environments. You can use properties files, YAML files, -environment variables, and command-line arguments to externalize configuration. Property -values can be injected directly into your beans by using the `@Value` annotation, -accessed through Spring's `Environment` abstraction, or be -<> through `@ConfigurationProperties`. +Spring Boot lets you externalize your configuration so that you can work with the same application code in different environments. +You can use properties files, YAML files, environment variables, and command-line arguments to externalize configuration. +Property values can be injected directly into your beans by using the `@Value` annotation, accessed through Spring's `Environment` abstraction, or be <> through `@ConfigurationProperties`. -Spring Boot uses a very particular `PropertySource` order that is designed to allow -sensible overriding of values. Properties are considered in the following order: +Spring Boot uses a very particular `PropertySource` order that is designed to allow sensible overriding of values. +Properties are considered in the following order: -. <> -on your home directory (`~/.spring-boot-devtools.properties` when devtools is active). -. {spring-javadoc}/test/context/TestPropertySource.{dc-ext}[`@TestPropertySource`] -annotations on your tests. -. `properties` attribute on your tests. Available on -{dc-spring-boot-test}/context/SpringBootTest.{dc-ext}[`@SpringBootTest`] and the -<>. +. <> on your home directory (`~/.spring-boot-devtools.properties` when devtools is active). +. {spring-javadoc}/test/context/TestPropertySource.{dc-ext}[`@TestPropertySource`] annotations on your tests. +. `properties` attribute on your tests. + Available on {dc-spring-boot-test}/context/SpringBootTest.{dc-ext}[`@SpringBootTest`] and the <>. . Command line arguments. -. Properties from `SPRING_APPLICATION_JSON` (inline JSON embedded in an environment -variable or system property). +. Properties from `SPRING_APPLICATION_JSON` (inline JSON embedded in an environment variable or system property). . `ServletConfig` init parameters. . `ServletContext` init parameters. . JNDI attributes from `java:comp/env`. . Java System properties (`System.getProperties()`). . OS environment variables. . A `RandomValuePropertySource` that has properties only in `+random.*+`. -. <> outside of your packaged jar -(`application-\{profile}.properties` and YAML variants). -. <> packaged inside your jar (`application-\{profile}.properties` -and YAML variants). -. Application properties outside of your packaged jar (`application.properties` and YAML -variants). -. Application properties packaged inside your jar (`application.properties` and YAML -variants). -. {spring-javadoc}/context/annotation/PropertySource.{dc-ext}[`@PropertySource`] -annotations on your `@Configuration` classes. +. <> outside of your packaged jar (`application-\{profile}.properties` and YAML variants). +. <> packaged inside your jar (`application-\{profile}.properties` and YAML variants). +. Application properties outside of your packaged jar (`application.properties` and YAML variants). +. Application properties packaged inside your jar (`application.properties` and YAML variants). +. {spring-javadoc}/context/annotation/PropertySource.{dc-ext}[`@PropertySource`] annotations on your `@Configuration` classes. . Default properties (specified by setting `SpringApplication.setDefaultProperties`). -To provide a concrete example, suppose you develop a `@Component` that uses a `name` -property, as shown in the following example: +To provide a concrete example, suppose you develop a `@Component` that uses a `name` property, as shown in the following example: [source,java,indent=0] ---- @@ -449,48 +368,44 @@ property, as shown in the following example: } ---- -On your application classpath (for example, inside your jar) you can have an -`application.properties` file that provides a sensible default property value for `name`. -When running in a new environment, an `application.properties` file can be provided -outside of your jar that overrides the `name`. For one-off testing, you can launch with a -specific command line switch (for example, `java -jar app.jar --name="Spring"`). +On your application classpath (for example, inside your jar) you can have an `application.properties` file that provides a sensible default property value for `name`. +When running in a new environment, an `application.properties` file can be provided outside of your jar that overrides the `name`. +For one-off testing, you can launch with a specific command line switch (for example, `java -jar app.jar --name="Spring"`). [TIP] ==== -The `SPRING_APPLICATION_JSON` properties can be supplied on the command line with an -environment variable. For example, you could use the following line in a UN{asterisk}X -shell: +The `SPRING_APPLICATION_JSON` properties can be supplied on the command line with an environment variable. +For example, you could use the following line in a UN{asterisk}X shell: +[indent=0] ---- -$ SPRING_APPLICATION_JSON='{"acme":{"name":"test"}}' java -jar myapp.jar + $ SPRING_APPLICATION_JSON='{"acme":{"name":"test"}}' java -jar myapp.jar ---- In the preceding example, you end up with `acme.name=test` in the Spring `Environment`. -You can also supply the JSON as `spring.application.json` in a System property, as shown -in the following example: +You can also supply the JSON as `spring.application.json` in a System property, as shown in the following example: +[indent=0] ---- -$ java -Dspring.application.json='{"name":"test"}' -jar myapp.jar + $ java -Dspring.application.json='{"name":"test"}' -jar myapp.jar ---- -You can also supply the JSON by using a command line argument, as shown in the following -example: +You can also supply the JSON by using a command line argument, as shown in the following example: +[indent=0] ---- -$ java -jar myapp.jar --spring.application.json='{"name":"test"}' + $ java -jar myapp.jar --spring.application.json='{"name":"test"}' ---- -You can also supply the JSON as a JNDI variable, as follows: -`java:comp/env/spring.application.json`. +You can also supply the JSON as a JNDI variable, as follows: `java:comp/env/spring.application.json`. ==== [[boot-features-external-config-random-values]] === Configuring Random Values -The `RandomValuePropertySource` is useful for injecting random values (for example, into -secrets or test cases). It can produce integers, longs, uuids, or strings, as shown in the -following example: +The `RandomValuePropertySource` is useful for injecting random values (for example, into secrets or test cases). +It can produce integers, longs, uuids, or strings, as shown in the following example: [source,properties,indent=0] ---- @@ -502,45 +417,36 @@ following example: my.number.in.range=${random.int[1024,65536]} ---- -The `+random.int*+` syntax is `OPEN value (,max) CLOSE` where the `OPEN,CLOSE` are any -character and `value,max` are integers. If `max` is provided, then `value` is the minimum -value and `max` is the maximum value (exclusive). +The `+random.int*+` syntax is `OPEN value (,max) CLOSE` where the `OPEN,CLOSE` are any character and `value,max` are integers. +If `max` is provided, then `value` is the minimum value and `max` is the maximum value (exclusive). [[boot-features-external-config-command-line-args]] === Accessing Command Line Properties -By default, `SpringApplication` converts any command line option arguments (that is, -arguments starting with `--`, such as `--server.port=9000`) to a `property` and adds -them to the Spring `Environment`. As mentioned previously, command line properties always -take precedence over other property sources. +By default, `SpringApplication` converts any command line option arguments (that is, arguments starting with `--`, such as `--server.port=9000`) to a `property` and adds them to the Spring `Environment`. +As mentioned previously, command line properties always take precedence over other property sources. -If you do not want command line properties to be added to the `Environment`, you can -disable them by using `SpringApplication.setAddCommandLineProperties(false)`. +If you do not want command line properties to be added to the `Environment`, you can disable them by using `SpringApplication.setAddCommandLineProperties(false)`. [[boot-features-external-config-application-property-files]] === Application Property Files -`SpringApplication` loads properties from `application.properties` files in the following -locations and adds them to the Spring `Environment`: +`SpringApplication` loads properties from `application.properties` files in the following locations and adds them to the Spring `Environment`: . A `/config` subdirectory of the current directory . The current directory . A classpath `/config` package . The classpath root -The list is ordered by precedence (properties defined in locations higher in the list -override those defined in lower locations). +The list is ordered by precedence (properties defined in locations higher in the list override those defined in lower locations). -NOTE: You can also <> as an -alternative to '.properties'. +NOTE: You can also <> as an alternative to '.properties'. -If you do not like `application.properties` as the configuration file name, you can -switch to another file name by specifying a `spring.config.name` environment property. -You can also refer to an explicit location by using the `spring.config.location` -environment property (which is a comma-separated list of directory locations or file -paths). The following example shows how to specify a different file name: +If you do not like `application.properties` as the configuration file name, you can switch to another file name by specifying a `spring.config.name` environment property. +You can also refer to an explicit location by using the `spring.config.location` environment property (which is a comma-separated list of directory locations or file paths). +The following example shows how to specify a different file name: [indent=0] ---- @@ -554,39 +460,30 @@ The following example shows how to specify two locations: $ java -jar myproject.jar --spring.config.location=classpath:/default.properties,classpath:/override.properties ---- -WARNING: `spring.config.name` and `spring.config.location` are used very early to -determine which files have to be loaded, so they must be defined as an environment -property (typically an OS environment variable, a system property, or a command-line -argument). +WARNING: `spring.config.name` and `spring.config.location` are used very early to determine which files have to be loaded. +They must be defined as an environment property (typically an OS environment variable, a system property, or a command-line argument). -If `spring.config.location` contains directories (as opposed to files), they should end -in `/` (and, at runtime, be appended with the names generated from `spring.config.name` -before being loaded, including profile-specific file names). Files specified in -`spring.config.location` are used as-is, with no support for profile-specific variants, -and are overridden by any profile-specific properties. +If `spring.config.location` contains directories (as opposed to files), they should end in `/` (and, at runtime, be appended with the names generated from `spring.config.name` before being loaded, including profile-specific file names). +Files specified in `spring.config.location` are used as-is, with no support for profile-specific variants, and are overridden by any profile-specific properties. -Config locations are searched in reverse order. By default, the configured locations are -`classpath:/,classpath:/config/,file:./,file:./config/`. The resulting search order is -the following: +Config locations are searched in reverse order. +By default, the configured locations are `classpath:/,classpath:/config/,file:./,file:./config/`. +The resulting search order is the following: . `file:./config/` . `file:./` . `classpath:/config/` . `classpath:/` -When custom config locations are configured by using `spring.config.location`, they -replace the default locations. For example, if `spring.config.location` is configured with -the value `classpath:/custom-config/,file:./custom-config/`, the search order becomes the -following: +When custom config locations are configured by using `spring.config.location`, they replace the default locations. +For example, if `spring.config.location` is configured with the value `classpath:/custom-config/,file:./custom-config/`, the search order becomes the following: . `file:./custom-config/` . `classpath:custom-config/` -Alternatively, when custom config locations are configured by using -`spring.config.additional-location`, they are used in addition to the default locations. -Additional locations are searched before the default locations. For example, if -additional locations of `classpath:/custom-config/,file:./custom-config/` are configured, -the search order becomes the following: +Alternatively, when custom config locations are configured by using `spring.config.additional-location`, they are used in addition to the default locations. +Additional locations are searched before the default locations. +For example, if additional locations of `classpath:/custom-config/,file:./custom-config/` are configured, the search order becomes the following: . `file:./custom-config/` . `classpath:custom-config/` @@ -595,50 +492,34 @@ the search order becomes the following: . `classpath:/config/` . `classpath:/` -This search ordering lets you specify default values in one configuration file and then -selectively override those values in another. You can provide default values for your -application in `application.properties` (or whatever other basename you choose with -`spring.config.name`) in one of the default locations. These default values can then be -overridden at runtime with a different file located in one of the custom locations. +This search ordering lets you specify default values in one configuration file and then selectively override those values in another. +You can provide default values for your application in `application.properties` (or whatever other basename you choose with `spring.config.name`) in one of the default locations. +These default values can then be overridden at runtime with a different file located in one of the custom locations. -NOTE: If you use environment variables rather than system properties, most operating -systems disallow period-separated key names, but you can use underscores instead (for -example, `SPRING_CONFIG_NAME` instead of `spring.config.name`). +NOTE: If you use environment variables rather than system properties, most operating systems disallow period-separated key names, but you can use underscores instead (for example, `SPRING_CONFIG_NAME` instead of `spring.config.name`). -NOTE: If your application runs in a container, then JNDI properties (in `java:comp/env`) -or servlet context initialization parameters can be used instead of, or as well as, -environment variables or system properties. +NOTE: If your application runs in a container, then JNDI properties (in `java:comp/env`) or servlet context initialization parameters can be used instead of, or as well as, environment variables or system properties. [[boot-features-external-config-profile-specific-properties]] === Profile-specific Properties -In addition to `application.properties` files, profile-specific properties can also be -defined by using the following naming convention: `application-\{profile}.properties`. The -`Environment` has a set of default profiles (by default, `[default]`) that are used if no -active profiles are set. In other words, if no profiles are explicitly activated, then -properties from `application-default.properties` are loaded. +In addition to `application.properties` files, profile-specific properties can also be defined by using the following naming convention: `application-\{profile}.properties`. +The `Environment` has a set of default profiles (by default, `[default]`) that are used if no active profiles are set. In other words, if no profiles are explicitly activated, then properties from `application-default.properties` are loaded. -Profile-specific properties are loaded from the same locations as standard -`application.properties`, with profile-specific files always overriding the non-specific -ones, whether or not the profile-specific files are inside or outside your -packaged jar. +Profile-specific properties are loaded from the same locations as standard `application.properties`, with profile-specific files always overriding the non-specific ones, whether or not the profile-specific files are inside or outside your packaged jar. -If several profiles are specified, a last-wins strategy applies. For example, profiles -specified by the `spring.profiles.active` property are added after those configured -through the `SpringApplication` API and therefore take precedence. +If several profiles are specified, a last-wins strategy applies. +For example, profiles specified by the `spring.profiles.active` property are added after those configured through the `SpringApplication` API and therefore take precedence. -NOTE: If you have specified any files in `spring.config.location`, profile-specific -variants of those files are not considered. Use directories in -`spring.config.location` if you want to also use profile-specific properties. +NOTE: If you have specified any files in `spring.config.location`, profile-specific variants of those files are not considered. +Use directories in `spring.config.location` if you want to also use profile-specific properties. [[boot-features-external-config-placeholders-in-properties]] === Placeholders in Properties -The values in `application.properties` are filtered through the existing `Environment` -when they are used, so you can refer back to previously defined values (for example, from -System properties). +The values in `application.properties` are filtered through the existing `Environment` when they are used, so you can refer back to previously defined values (for example, from System properties). [source,properties,indent=0] ---- @@ -646,44 +527,34 @@ System properties). app.description=${app.name} is a Spring Boot application ---- -TIP: You can also use this technique to create "`short`" variants of existing Spring Boot -properties. See the _<>_ how-to for -details. +TIP: You can also use this technique to create "`short`" variants of existing Spring Boot properties. +See the _<>_ how-to for details. [[boot-features-encrypting-properties]] === Encrypting Properties -Spring Boot does not provide any built in support for encrypting property values, however, -it does provide the hook points necessary to modify values contained in the Spring -`Environment`. The `EnvironmentPostProcessor` interface allows you to manipulate the -`Environment` before the application starts. See <> -for details. +Spring Boot does not provide any built in support for encrypting property values, however, it does provide the hook points necessary to modify values contained in the Spring `Environment`. +The `EnvironmentPostProcessor` interface allows you to manipulate the `Environment` before the application starts. +See <> for details. -If you're looking for a secure way to store credentials and passwords, the -https://cloud.spring.io/spring-cloud-vault/[Spring Cloud Vault] project provides -support for storing externalized configuration in -https://www.vaultproject.io/[HashiCorp Vault]. +If you're looking for a secure way to store credentials and passwords, the https://cloud.spring.io/spring-cloud-vault/[Spring Cloud Vault] project provides support for storing externalized configuration in https://www.vaultproject.io/[HashiCorp Vault]. [[boot-features-external-config-yaml]] === Using YAML Instead of Properties -https://yaml.org[YAML] is a superset of JSON and, as such, is a convenient format for -specifying hierarchical configuration data. The `SpringApplication` class automatically -supports YAML as an alternative to properties whenever you have the -https://bitbucket.org/asomov/snakeyaml[SnakeYAML] library on your classpath. +https://yaml.org[YAML] is a superset of JSON and, as such, is a convenient format for specifying hierarchical configuration data. +The `SpringApplication` class automatically supports YAML as an alternative to properties whenever you have the https://bitbucket.org/asomov/snakeyaml[SnakeYAML] library on your classpath. -NOTE: If you use "`Starters`", SnakeYAML is automatically provided by -`spring-boot-starter`. +NOTE: If you use "`Starters`", SnakeYAML is automatically provided by `spring-boot-starter`. [[boot-features-external-config-loading-yaml]] ==== Loading YAML Spring Framework provides two convenient classes that can be used to load YAML documents. -The `YamlPropertiesFactoryBean` loads YAML as `Properties` and the `YamlMapFactoryBean` -loads YAML as a `Map`. +The `YamlPropertiesFactoryBean` loads YAML as `Properties` and the `YamlMapFactoryBean` loads YAML as a `Map`. For example, consider the following YAML document: @@ -708,8 +579,8 @@ The preceding example would be transformed into the following properties: environments.prod.name=My Cool App ---- -YAML lists are represented as property keys with `[index]` dereferencers. For example, -consider the following YAML: +YAML lists are represented as property keys with `[index]` dereferencers. +For example, consider the following YAML: [source,yaml,indent=0] ---- @@ -727,11 +598,8 @@ The preceding example would be transformed into these properties: my.servers[1]=another.example.com ---- -To bind to properties like that by using Spring Boot's `Binder` utilities (which is what -`@ConfigurationProperties` does), you need to have a property in the target bean of type -`java.util.List` (or `Set`) and you either need to provide a setter or initialize it with -a mutable value. For example, the following example binds to the properties shown -previously: +To bind to properties like that by using Spring Boot's `Binder` utilities (which is what `@ConfigurationProperties` does), you need to have a property in the target bean of type `java.util.List` (or `Set`) and you either need to provide a setter or initialize it with a mutable value. +For example, the following example binds to the properties shown previously: [source,java,indent=0] ---- @@ -750,17 +618,14 @@ previously: [[boot-features-external-config-exposing-yaml-to-spring]] ==== Exposing YAML as Properties in the Spring Environment -The `YamlPropertySourceLoader` class can be used to expose YAML as a `PropertySource` in -the Spring `Environment`. Doing so lets you use the `@Value` annotation with placeholders -syntax to access YAML properties. +The `YamlPropertySourceLoader` class can be used to expose YAML as a `PropertySource` in the Spring `Environment`. +Doing so lets you use the `@Value` annotation with placeholders syntax to access YAML properties. [[boot-features-external-config-multi-profile-yaml]] ==== Multi-profile YAML Documents -You can specify multiple profile-specific YAML documents in a single file by using a -`spring.profiles` key to indicate when the document applies, as shown in the following -example: +You can specify multiple profile-specific YAML documents in a single file by using a `spring.profiles` key to indicate when the document applies, as shown in the following example: [source,yaml,indent=0] ---- @@ -778,24 +643,19 @@ example: address: 192.168.1.120 ---- -In the preceding example, if the `development` profile is active, the `server.address` -property is `127.0.0.1`. Similarly, if the `production` *and* `eu-central` profiles are -active, the `server.address` property is `192.168.1.120`. If the `development`, -`production` and `eu-central` profiles are *not* enabled, then the value for the property -is `192.168.1.100`. +In the preceding example, if the `development` profile is active, the `server.address` property is `127.0.0.1`. +Similarly, if the `production` *and* `eu-central` profiles are active, the `server.address` property is `192.168.1.120`. +If the `development`, `production` and `eu-central` profiles are *not* enabled, then the value for the property is `192.168.1.100`. [NOTE] ==== -`spring.profiles` can therefore contain a simple profile name (for example `production`) -or a profile expression. A profile expression allows for more complicated profile logic -to be expressed, for example `production & (eu-central | eu-west)`. Check the -{spring-reference}core.html#beans-definition-profiles-java[reference guide] for more -details. +`spring.profiles` can therefore contain a simple profile name (for example `production`) or a profile expression. +A profile expression allows for more complicated profile logic to be expressed, for example `production & (eu-central | eu-west)`. +Check the {spring-reference}core.html#beans-definition-profiles-java[reference guide] for more details. ==== -If none are explicitly active when the application context starts, the default profiles -are activated. So, in the following YAML, we set a value for `spring.security.user.password` -that is available *only* in the "default" profile: +If none are explicitly active when the application context starts, the default profiles are activated. +So, in the following YAML, we set a value for `spring.security.user.password` that is available *only* in the "default" profile: [source,yaml,indent=0] ---- @@ -809,9 +669,7 @@ that is available *only* in the "default" profile: password: weak ---- -Whereas, in the following example, the password is always set because it is not attached -to any profile, and it would have to be explicitly reset in all other profiles as -necessary: +Whereas, in the following example, the password is always set because it is not attached to any profile, and it would have to be explicitly reset in all other profiles as necessary: [source,yaml,indent=0] ---- @@ -823,21 +681,18 @@ necessary: password: weak ---- -Spring profiles designated by using the `spring.profiles` element may optionally be -negated by using the `!` character. If both negated and non-negated profiles are -specified for a single document, at least one non-negated profile must match, and no -negated profiles may match. +Spring profiles designated by using the `spring.profiles` element may optionally be negated by using the `!` character. +If both negated and non-negated profiles are specified for a single document, at least one non-negated profile must match, and no negated profiles may match. [[boot-features-external-config-yaml-shortcomings]] ==== YAML Shortcomings -YAML files cannot be loaded by using the `@PropertySource` annotation. So, in the case -that you need to load values that way, you need to use a properties file. +YAML files cannot be loaded by using the `@PropertySource` annotation. +So, in the case that you need to load values that way, you need to use a properties file. -Using the multi YAML document syntax in profile-specific YAML files can lead to unexpected -behavior. For example, consider the following config in a file called `application-dev.yml`, -with the `dev` profile being active: +Using the multi YAML document syntax in profile-specific YAML files can lead to unexpected behavior. +For example, consider the following config in a file called `application-dev.yml`, with the `dev` profile being active: [source,yaml,indent=0] ---- @@ -852,18 +707,14 @@ with the `dev` profile being active: ---- In the example above, profile negation and profile expressions will not behave as expected. -We recommend that you don't combine profile-specific YAML files and multiple YAML documents and stick -to using only one of them. +We recommend that you don't combine profile-specific YAML files and multiple YAML documents and stick to using only one of them. [[boot-features-external-config-typesafe-configuration-properties]] === Type-safe Configuration Properties -Using the `@Value("$\{property}")` annotation to inject configuration properties can -sometimes be cumbersome, especially if you are working with multiple properties or your -data is hierarchical in nature. Spring Boot provides an alternative method of working -with properties that lets strongly typed beans govern and validate the configuration of -your application, as shown in the following example: +Using the `@Value("$\{property}")` annotation to inject configuration properties can sometimes be cumbersome, especially if you are working with multiple properties or your data is hierarchical in nature. +Spring Boot provides an alternative method of working with properties that lets strongly typed beans govern and validate the configuration of your application, as shown in the following example: [source,java,indent=0] ---- @@ -923,47 +774,37 @@ The preceding POJO defines the following properties: * `acme.enabled`, with a value of `false` by default. * `acme.remote-address`, with a type that can be coerced from `String`. -* `acme.security.username`, with a nested "security" object whose name is determined by -the name of the property. In particular, the return type is not used at all there and -could have been `SecurityProperties`. +* `acme.security.username`, with a nested "security" object whose name is determined by the name of the property. + In particular, the return type is not used at all there and could have been `SecurityProperties`. * `acme.security.password`. * `acme.security.roles`, with a collection of `String`. -NOTE: Spring Boot auto-configuration heavily makes use of `@ConfigurationProperties` for easily -configuring auto-configured beans. Similar to auto-configuration classes, `@ConfigurationProperties` -classes available in Spring Boot are for internal use only. The properties that map to the class, -which are configured via properties files, YAML files, environment variables etc., are public API but -the content of the class itself is not meant to be used directly. +NOTE: Spring Boot auto-configuration heavily makes use of `@ConfigurationProperties` for easily configuring auto-configured beans. +Similar to auto-configuration classes, `@ConfigurationProperties` classes available in Spring Boot are for internal use only. +The properties that map to the class, which are configured via properties files, YAML files, environment variables etc., are public API but the content of the class itself is not meant to be used directly. [NOTE] ==== -Getters and setters are usually mandatory, since binding is through standard Java Beans -property descriptors, just like in Spring MVC. A setter may be omitted in the following -cases: +Getters and setters are usually mandatory, since binding is through standard Java Beans property descriptors, just like in Spring MVC. +A setter may be omitted in the following cases: -* Maps, as long as they are initialized, need a getter but not necessarily a setter, -since they can be mutated by the binder. -* Collections and arrays can be accessed either through an index (typically with YAML) or -by using a single comma-separated value (properties). In the latter case, a setter is -mandatory. We recommend to always add a setter for such types. If you initialize a -collection, make sure it is not immutable (as in the preceding example). -* If nested POJO properties are initialized (like the `Security` field in the preceding -example), a setter is not required. If you want the binder to create the instance on the -fly by using its default constructor, you need a setter. +* Maps, as long as they are initialized, need a getter but not necessarily a setter, since they can be mutated by the binder. +* Collections and arrays can be accessed either through an index (typically with YAML) or by using a single comma-separated value (properties). + In the latter case, a setter is mandatory. + We recommend to always add a setter for such types. + If you initialize a collection, make sure it is not immutable (as in the preceding example). +* If nested POJO properties are initialized (like the `Security` field in the preceding example), a setter is not required. + If you want the binder to create the instance on the fly by using its default constructor, you need a setter. -Some people use Project Lombok to add getters and setters automatically. Make sure that -Lombok does not generate any particular constructor for such a type, as it is used -automatically by the container to instantiate the object. +Some people use Project Lombok to add getters and setters automatically. +Make sure that Lombok does not generate any particular constructor for such a type, as it is used automatically by the container to instantiate the object. -Finally, only standard Java Bean properties are considered and binding on static -properties is not supported. +Finally, only standard Java Bean properties are considered and binding on static properties is not supported. ==== -TIP: See also the <>. +TIP: See also the <>. -You also need to list the properties classes to register in the -`@EnableConfigurationProperties` annotation, as shown in the following example: +You also need to list the properties classes to register in the `@EnableConfigurationProperties` annotation, as shown in the following example: [source,java,indent=0] ---- @@ -975,23 +816,16 @@ You also need to list the properties classes to register in the [NOTE] ==== -When the `@ConfigurationProperties` bean is registered that way, the bean has a -conventional name: `-`, where `` is the environment key prefix -specified in the `@ConfigurationProperties` annotation and `` is the fully qualified -name of the bean. If the annotation does not provide any prefix, only the fully qualified -name of the bean is used. +When the `@ConfigurationProperties` bean is registered that way, the bean has a conventional name: `-`, where `` is the environment key prefix specified in the `@ConfigurationProperties` annotation and `` is the fully qualified name of the bean. +If the annotation does not provide any prefix, only the fully qualified name of the bean is used. The bean name in the example above is `acme-com.example.AcmeProperties`. ==== -The preceding configuration creates a regular bean for `AcmeProperties`. We recommend that -`@ConfigurationProperties` only deal with the environment and, in particular, does not -inject other beans from the context. Keep in mind that the -`@EnableConfigurationProperties` annotation is _also_ automatically applied to your -project so that any _existing_ bean annotated with `@ConfigurationProperties` is -configured from the `Environment`. Instead of annotating `MyConfiguration` with -`@EnableConfigurationProperties(AcmeProperties.class)`, you could make `AcmeProperties` -a bean, as shown in the following example: +The preceding configuration creates a regular bean for `AcmeProperties`. +We recommend that `@ConfigurationProperties` only deal with the environment and, in particular, does not inject other beans from the context. +Keep in mind that the `@EnableConfigurationProperties` annotation is _also_ automatically applied to your project so that any _existing_ bean annotated with `@ConfigurationProperties` is configured from the `Environment`. +Instead of annotating `MyConfiguration` with `@EnableConfigurationProperties(AcmeProperties.class)`, you could make `AcmeProperties` a bean, as shown in the following example: [source,java,indent=0] ---- @@ -1004,8 +838,7 @@ a bean, as shown in the following example: } ---- -This style of configuration works particularly well with the `SpringApplication` external -YAML configuration, as shown in the following example: +This style of configuration works particularly well with the `SpringApplication` external YAML configuration, as shown in the following example: [source,yaml,indent=0] ---- @@ -1022,8 +855,7 @@ YAML configuration, as shown in the following example: # additional configuration as required ---- -To work with `@ConfigurationProperties` beans, you can inject them in the same way -as any other bean, as shown in the following example: +To work with `@ConfigurationProperties` beans, you can inject them in the same way as any other bean, as shown in the following example: [source,java,indent=0] ---- @@ -1048,20 +880,17 @@ as any other bean, as shown in the following example: } ---- -TIP: Using `@ConfigurationProperties` also lets you generate metadata files that can be -used by IDEs to offer auto-completion for your own keys. See the -<> appendix for details. +TIP: Using `@ConfigurationProperties` also lets you generate metadata files that can be used by IDEs to offer auto-completion for your own keys. +See the <> appendix for details. [[boot-features-external-config-3rd-party-configuration]] ==== Third-party Configuration -As well as using `@ConfigurationProperties` to annotate a class, you can also use it on -public `@Bean` methods. Doing so can be particularly useful when you want to bind -properties to third-party components that are outside of your control. +As well as using `@ConfigurationProperties` to annotate a class, you can also use it on public `@Bean` methods. +Doing so can be particularly useful when you want to bind properties to third-party components that are outside of your control. -To configure a bean from the `Environment` properties, add `@ConfigurationProperties` to -its bean registration, as shown in the following example: +To configure a bean from the `Environment` properties, add `@ConfigurationProperties` to its bean registration, as shown in the following example: [source,java,indent=0] ---- @@ -1072,21 +901,16 @@ its bean registration, as shown in the following example: } ---- -Any property defined with the `another` prefix is mapped onto that `AnotherComponent` bean -in manner similar to the preceding `AcmeProperties` example. +Any property defined with the `another` prefix is mapped onto that `AnotherComponent` bean in manner similar to the preceding `AcmeProperties` example. [[boot-features-external-config-relaxed-binding]] ==== Relaxed Binding -Spring Boot uses some relaxed rules for binding `Environment` properties to -`@ConfigurationProperties` beans, so there does not need to be an exact match between the -`Environment` property name and the bean property name. Common examples where this is -useful include dash-separated environment properties (for example, `context-path` binds -to `contextPath`), and capitalized environment properties (for example, `PORT` binds to -`port`). +Spring Boot uses some relaxed rules for binding `Environment` properties to `@ConfigurationProperties` beans, so there does not need to be an exact match between the `Environment` property name and the bean property name. +Common examples where this is useful include dash-separated environment properties (for example, `context-path` binds to `contextPath`), and capitalized environment properties (for example, `PORT` binds to `port`). -For example, consider the following `@ConfigurationProperties` class: +As an example, consider the following `@ConfigurationProperties` class: [source,java,indent=0] ---- @@ -1106,60 +930,55 @@ For example, consider the following `@ConfigurationProperties` class: } ---- -In the preceding example, the following properties names can all be used: +With the preceding code, the following properties names can all be used: .relaxed binding [cols="1,4"] |=== | Property | Note -|`acme.my-project.person.first-name` -|Kebab case, which is recommended for use in `.properties` and `.yml` files. +| `acme.my-project.person.first-name` +| Kebab case, which is recommended for use in `.properties` and `.yml` files. -|`acme.myProject.person.firstName` -|Standard camel case syntax. +| `acme.myProject.person.firstName` +| Standard camel case syntax. -|`acme.my_project.person.first_name` -|Underscore notation, which is an alternative format for use in `.properties` and `.yml` -files. +| `acme.my_project.person.first_name` +| Underscore notation, which is an alternative format for use in `.properties` and `.yml` files. -|`ACME_MYPROJECT_PERSON_FIRSTNAME` -|Upper case format, which is recommended when using system environment variables. +| `ACME_MYPROJECT_PERSON_FIRSTNAME` +| Upper case format, which is recommended when using system environment variables. |=== -NOTE: The `prefix` value for the annotation _must_ be in kebab case (lowercase and -separated by `-`, such as `acme.my-project.person`). +NOTE: The `prefix` value for the annotation _must_ be in kebab case (lowercase and separated by `-`, such as `acme.my-project.person`). .relaxed binding rules per property source [cols="2,4,4"] |=== | Property Source | Simple | List -|Properties Files -|Camel case, kebab case, or underscore notation -|Standard list syntax using `[ ]` or comma-separated values +| Properties Files +| Camel case, kebab case, or underscore notation +| Standard list syntax using `[ ]` or comma-separated values -|YAML Files -|Camel case, kebab case, or underscore notation -|Standard YAML list syntax or comma-separated values +| YAML Files +| Camel case, kebab case, or underscore notation +| Standard YAML list syntax or comma-separated values -|Environment Variables -|Upper case format with underscore as the delimiter. `_` should not be used within a -property name -|Numeric values surrounded by underscores, such as `MY_ACME_1_OTHER = my.acme[1].other` +| Environment Variables +| Upper case format with underscore as the delimiter. `_` should not be used within a property name +| Numeric values surrounded by underscores, such as `MY_ACME_1_OTHER = my.acme[1].other` -|System properties -|Camel case, kebab case, or underscore notation -|Standard list syntax using `[ ]` or comma-separated values +| System properties +| Camel case, kebab case, or underscore notation +| Standard list syntax using `[ ]` or comma-separated values |=== -TIP: We recommend that, when possible, properties are stored in lower-case kebab format, -such as `my.property-name=acme`. +TIP: We recommend that, when possible, properties are stored in lower-case kebab format, such as `my.property-name=acme`. -When binding to `Map` properties, if the `key` contains anything other than lowercase -alpha-numeric characters or `-`, you need to use the bracket notation so that the original -value is preserved. If the key is not surrounded by `[]`, any characters that are not alpha-numeric -or `-` are removed. For example, consider binding the following properties to a `Map`: +When binding to `Map` properties, if the `key` contains anything other than lowercase alpha-numeric characters or `-`, you need to use the bracket notation so that the original value is preserved. +If the key is not surrounded by `[]`, any characters that are not alpha-numeric or `-` are removed. +For example, consider binding the following properties to a `Map`: [source,yaml,indent=0] ---- @@ -1176,12 +995,10 @@ The properties above will bind to a `Map` with `/key1`, `/key2` and `key3` as th [[boot-features-external-config-complex-type-merge]] ==== Merging Complex Types -When lists are configured in more than one place, overriding works by replacing the entire -list. +When lists are configured in more than one place, overriding works by replacing the entire list. -For example, assume a `MyPojo` object with `name` and `description` attributes that are -`null` by default. The following example exposes a list of `MyPojo` objects from -`AcmeProperties`: +For example, assume a `MyPojo` object with `name` and `description` attributes that are `null` by default. +The following example exposes a list of `MyPojo` objects from `AcmeProperties`: [source,java,indent=0] ---- @@ -1213,14 +1030,12 @@ Consider the following configuration: - name: my another name ---- -If the `dev` profile is not active, `AcmeProperties.list` contains one `MyPojo` entry, -as previously defined. If the `dev` profile is enabled, however, the `list` _still_ -contains only one entry (with a name of `my another name` and a description of `null`). -This configuration _does not_ add a second `MyPojo` instance to the list, and it does not -merge the items. +If the `dev` profile is not active, `AcmeProperties.list` contains one `MyPojo` entry, as previously defined. +If the `dev` profile is enabled, however, the `list` _still_ contains only one entry (with a name of `my another name` and a description of `null`). +This configuration _does not_ add a second `MyPojo` instance to the list, and it does not merge the items. -When a `List` is specified in multiple profiles, the one with the highest priority -(and only that one) is used. Consider the following example: +When a `List` is specified in multiple profiles, the one with the highest priority (and only that one) is used. +Consider the following example: [source,yaml,indent=0] ---- @@ -1238,13 +1053,11 @@ When a `List` is specified in multiple profiles, the one with the highest priori - name: my another name ---- -In the preceding example, if the `dev` profile is active, `AcmeProperties.list` contains -_one_ `MyPojo` entry (with a name of `my another name` and a description of `null`). -For YAML, both comma-separated lists and YAML lists can be used for -completely overriding the contents of the list. +In the preceding example, if the `dev` profile is active, `AcmeProperties.list` contains _one_ `MyPojo` entry (with a name of `my another name` and a description of `null`). +For YAML, both comma-separated lists and YAML lists can be used for completely overriding the contents of the list. -For `Map` properties, you can bind with property values drawn from multiple sources. However, -for the same property in multiple sources, the one with the highest priority is used. +For `Map` properties, you can bind with property values drawn from multiple sources. +However, for the same property in multiple sources, the one with the highest priority is used. The following example exposes a `Map` from `AcmeProperties`: [source,java,indent=0] @@ -1282,44 +1095,32 @@ Consider the following configuration: description: dev description 2 ---- -If the `dev` profile is not active, `AcmeProperties.map` contains one entry with key `key1` -(with a name of `my name 1` and a description of `my description 1`). -If the `dev` profile is enabled, however, `map` contains two entries with keys `key1` -(with a name of `dev name 1` and a description of `my description 1`) and -`key2` (with a name of `dev name 2` and a description of `dev description 2`). +If the `dev` profile is not active, `AcmeProperties.map` contains one entry with key `key1` (with a name of `my name 1` and a description of `my description 1`). +If the `dev` profile is enabled, however, `map` contains two entries with keys `key1` (with a name of `dev name 1` and a description of `my description 1`) and `key2` (with a name of `dev name 2` and a description of `dev description 2`). + +NOTE: The preceding merging rules apply to properties from all property sources and not just YAML files. + -NOTE: The preceding merging rules apply to properties from all property sources and not just -YAML files. [[boot-features-external-config-conversion]] ==== Properties Conversion -Spring Boot attempts to coerce the external application properties to the right type when -it binds to the `@ConfigurationProperties` beans. If you need custom type conversion, you -can provide a `ConversionService` bean (with a bean named `conversionService`) or custom -property editors (through a `CustomEditorConfigurer` bean) or custom `Converters` (with -bean definitions annotated as `@ConfigurationPropertiesBinding`). +Spring Boot attempts to coerce the external application properties to the right type when it binds to the `@ConfigurationProperties` beans. +If you need custom type conversion, you can provide a `ConversionService` bean (with a bean named `conversionService`) or custom property editors (through a `CustomEditorConfigurer` bean) or custom `Converters` (with bean definitions annotated as `@ConfigurationPropertiesBinding`). -NOTE: As this bean is requested very early during the application lifecycle, make sure to -limit the dependencies that your `ConversionService` is using. Typically, any dependency -that you require may not be fully initialized at creation time. You may want to rename -your custom `ConversionService` if it is not required for configuration keys coercion and -only rely on custom converters qualified with `@ConfigurationPropertiesBinding`. +NOTE: As this bean is requested very early during the application lifecycle, make sure to limit the dependencies that your `ConversionService` is using. +Typically, any dependency that you require may not be fully initialized at creation time. +You may want to rename your custom `ConversionService` if it is not required for configuration keys coercion and only rely on custom converters qualified with `@ConfigurationPropertiesBinding`. [[boot-features-external-config-conversion-duration]] ===== Converting durations -Spring Boot has dedicated support for expressing durations. If you expose a -`java.time.Duration` property, the following formats in application properties are -available: +Spring Boot has dedicated support for expressing durations. +If you expose a `java.time.Duration` property, the following formats in application properties are available: -* A regular `long` representation (using milliseconds as the default unit unless a -`@DurationUnit` has been specified) -* The standard ISO-8601 format -{java-javadoc}/java/time/Duration.html#parse-java.lang.CharSequence-[used by -`java.time.Duration`] -* A more readable format where the value and the unit are coupled (e.g. `10s` means 10 -seconds) +* A regular `long` representation (using milliseconds as the default unit unless a `@DurationUnit` has been specified) +* The standard ISO-8601 format {java-javadoc}/java/time/Duration.html#parse-java.lang.CharSequence-[used by `java.time.Duration`] +* A more readable format where the value and the unit are coupled (e.g. `10s` means 10 seconds) Consider the following example: @@ -1328,9 +1129,8 @@ Consider the following example: include::{code-examples}/context/properties/bind/AppSystemProperties.java[tag=example] ---- -To specify a session timeout of 30 seconds, `30`, `PT30S` and `30s` are all equivalent. A -read timeout of 500ms can be specified in any of the following form: `500`, `PT0.5S` and -`500ms`. +To specify a session timeout of 30 seconds, `30`, `PT30S` and `30s` are all equivalent. +A read timeout of 500ms can be specified in any of the following form: `500`, `PT0.5S` and `500ms`. You can also use any of the supported units. These are: @@ -1342,26 +1142,20 @@ You can also use any of the supported units. These are: * `h` for hours * `d` for days -The default unit is milliseconds and can be overridden using `@DurationUnit` as illustrated -in the sample above. +The default unit is milliseconds and can be overridden using `@DurationUnit` as illustrated in the sample above. -TIP: If you are upgrading from a previous version that is simply using `Long` to express -the duration, make sure to define the unit (using `@DurationUnit`) if it isn't -milliseconds alongside the switch to `Duration`. Doing so gives a transparent upgrade path -while supporting a much richer format. +TIP: If you are upgrading from a previous version that is simply using `Long` to express the duration, make sure to define the unit (using `@DurationUnit`) if it isn't milliseconds alongside the switch to `Duration`. +Doing so gives a transparent upgrade path while supporting a much richer format. [[boot-features-external-config-conversion-datasize]] ===== Converting Data Sizes -Spring Framework has a `DataSize` value type that allows to express size in bytes. If you -expose a `DataSize` property, the following formats in application properties are -available: +Spring Framework has a `DataSize` value type that expresses a size in bytes. +If you expose a `DataSize` property, the following formats in application properties are available: -* A regular `long` representation (using bytes as the default unit unless a -`@DataSizeUnit` has been specified) -* A more readable format where the value and the unit are coupled (e.g. `10MB` means 10 -megabytes) +* A regular `long` representation (using bytes as the default unit unless a `@DataSizeUnit` has been specified) +* A more readable format where the value and the unit are coupled (e.g. `10MB` means 10 megabytes) Consider the following example: @@ -1370,8 +1164,8 @@ Consider the following example: include::{code-examples}/context/properties/bind/AppIoProperties.java[tag=example] ---- -To specify a buffer size of 10 megabytes, `10` and `10MB` are equivalent. A size threshold -of 256 bytes can be specified as `256` or `256B`. +To specify a buffer size of 10 megabytes, `10` and `10MB` are equivalent. +A size threshold of 256 bytes can be specified as `256` or `256B`. You can also use any of the supported units. These are: @@ -1381,23 +1175,18 @@ You can also use any of the supported units. These are: * `GB` for gigabytes * `TB` for terabytes -The default unit is bytes and can be overridden using `@DataSizeUnit` as illustrated -in the sample above. +The default unit is bytes and can be overridden using `@DataSizeUnit` as illustrated in the sample above. -TIP: If you are upgrading from a previous version that is simply using `Long` to express -the size, make sure to define the unit (using `@DataSizeUnit`) if it isn't bytes alongside -the switch to `DataSize`. Doing so gives a transparent upgrade path while supporting a -much richer format. +TIP: If you are upgrading from a previous version that is simply using `Long` to express the size, make sure to define the unit (using `@DataSizeUnit`) if it isn't bytes alongsidethe switch to `DataSize`. +Doing so gives a transparent upgrade path while supporting a much richer format. [[boot-features-external-config-validation]] ==== @ConfigurationProperties Validation -Spring Boot attempts to validate `@ConfigurationProperties` classes whenever they are -annotated with Spring's `@Validated` annotation. You can use JSR-303 `javax.validation` -constraint annotations directly on your configuration class. To do so, ensure that a -compliant JSR-303 implementation is on your classpath and then add constraint annotations -to your fields, as shown in the following example: +Spring Boot attempts to validate `@ConfigurationProperties` classes whenever they are annotated with Spring's `@Validated` annotation. +You can use JSR-303 `javax.validation` constraint annotations directly on your configuration class. +To do so, ensure that a compliant JSR-303 implementation is on your classpath and then add constraint annotations to your fields, as shown in the following example: [source,java,indent=0] ---- @@ -1413,13 +1202,11 @@ to your fields, as shown in the following example: } ---- -TIP: You can also trigger validation by annotating the `@Bean` method that creates the -configuration properties with `@Validated`. +TIP: You can also trigger validation by annotating the `@Bean` method that creates the configuration properties with `@Validated`. -Although nested properties will also be validated when bound, it's good practice to -also annotate the associated field as `@Valid`. This ensure that validation is triggered -even if no nested properties are found. The following example builds on the preceding -`AcmeProperties` example: +Although nested properties will also be validated when bound, it's good practice to also annotate the associated field as `@Valid`. +This ensures that validation is triggered even if no nested properties are found. +The following example builds on the preceding `AcmeProperties` example: [source,java,indent=0] ---- @@ -1447,32 +1234,26 @@ even if no nested properties are found. The following example builds on the prec } ---- -You can also add a custom Spring `Validator` by creating a bean definition called -`configurationPropertiesValidator`. The `@Bean` method should be declared `static`. The -configuration properties validator is created very early in the application's lifecycle, -and declaring the `@Bean` method as static lets the bean be created without having to -instantiate the `@Configuration` class. Doing so avoids any problems that may be caused -by early instantiation. There is a -{github-code}/spring-boot-samples/spring-boot-sample-property-validation[property -validation sample] that shows how to set things up. +You can also add a custom Spring `Validator` by creating a bean definition called `configurationPropertiesValidator`. +The `@Bean` method should be declared `static`. +The configuration properties validator is created very early in the application's lifecycle, and declaring the `@Bean` method as static lets the bean be created without having to instantiate the `@Configuration` class. +Doing so avoids any problems that may be caused by early instantiation. +There is a {github-code}/spring-boot-samples/spring-boot-sample-property-validation[property validation sample] that shows how to set things up. -TIP: The `spring-boot-actuator` module includes an endpoint that exposes all -`@ConfigurationProperties` beans. Point your web browser to -`/actuator/configprops` or use the equivalent JMX endpoint. See the -"<>" -section for details. +TIP: The `spring-boot-actuator` module includes an endpoint that exposes all `@ConfigurationProperties` beans. +Point your web browser to `/actuator/configprops` or use the equivalent JMX endpoint. +See the "<>" section for details. [[boot-features-external-config-vs-value]] ==== @ConfigurationProperties vs. @Value -The `@Value` annotation is a core container feature, and it does not provide the same -features as type-safe configuration properties. The following table summarizes the -features that are supported by `@ConfigurationProperties` and `@Value`: +The `@Value` annotation is a core container feature, and it does not provide the same features as type-safe configuration properties. +The following table summarizes the features that are supported by `@ConfigurationProperties` and `@Value`: [cols="4,2,2"] |=== -|Feature |`@ConfigurationProperties` |`@Value` +| Feature |`@ConfigurationProperties` |`@Value` | <> | Yes @@ -1487,23 +1268,17 @@ features that are supported by `@ConfigurationProperties` and `@Value`: | Yes |=== -If you define a set of configuration keys for your own components, we recommend you -group them in a POJO annotated with `@ConfigurationProperties`. You should also be aware -that, since `@Value` does not support relaxed binding, it is not a good candidate if you -need to provide the value by using environment variables. +If you define a set of configuration keys for your own components, we recommend you group them in a POJO annotated with `@ConfigurationProperties`. +You should also be aware that, since `@Value` does not support relaxed binding, it is not a good candidate if you need to provide the value by using environment variables. -Finally, while you can write a `SpEL` expression in `@Value`, such expressions are not -processed from <>. +Finally, while you can write a `SpEL` expression in `@Value`, such expressions are not processed from <>. [[boot-features-profiles]] == Profiles -Spring Profiles provide a way to segregate parts of your application configuration and -make it be available only in certain environments. Any `@Component` or `@Configuration` -can be marked with `@Profile` to limit when it is loaded, as shown in the following -example: +Spring Profiles provide a way to segregate parts of your application configuration and make it be available only in certain environments. +Any `@Component` or `@Configuration` can be marked with `@Profile` to limit when it is loaded, as shown in the following example: [source,java,indent=0] ---- @@ -1516,38 +1291,30 @@ example: } ---- -You can use a `spring.profiles.active` `Environment` property to specify which profiles -are active. You can specify the property in any of the ways described earlier in this -chapter. For example, you could include it in your `application.properties`, as shown in -the following example: +You can use a `spring.profiles.active` `Environment` property to specify which profiles are active. +You can specify the property in any of the ways described earlier in this chapter. +For example, you could include it in your `application.properties`, as shown in the following example: [source,properties,indent=0] ---- spring.profiles.active=dev,hsqldb ---- -You could also specify it on the command line by using the following switch: -`--spring.profiles.active=dev,hsqldb`. +You could also specify it on the command line by using the following switch: `--spring.profiles.active=dev,hsqldb`. [[boot-features-adding-active-profiles]] === Adding Active Profiles -The `spring.profiles.active` property follows the same ordering rules as other -properties: The highest `PropertySource` wins. This means that you can specify active -profiles in `application.properties` and then *replace* them by using the command line -switch. +The `spring.profiles.active` property follows the same ordering rules as other properties: The highest `PropertySource` wins. +This means that you can specify active profiles in `application.properties` and then *replace* them by using the command line switch. -Sometimes, it is useful to have profile-specific properties that *add* to the active -profiles rather than replace them. The `spring.profiles.include` property can be used to -unconditionally add active profiles. The `SpringApplication` entry point also has a Java -API for setting additional profiles (that is, on top of those activated by the -`spring.profiles.active` property). See the `setAdditionalProfiles()` method in -{dc-spring-boot}/SpringApplication.html[SpringApplication]. +Sometimes, it is useful to have profile-specific properties that *add* to the active profiles rather than replace them. +The `spring.profiles.include` property can be used to unconditionally add active profiles. +The `SpringApplication` entry point also has a Java API for setting additional profiles (that is, on top of those activated by the `spring.profiles.active` property). +See the `setAdditionalProfiles()` method in {dc-spring-boot}/SpringApplication.html[SpringApplication]. -For example, when an application with the following properties is run by using the -switch, `--spring.profiles.active=prod`, the `proddb` and `prodmq` profiles are also -activated: +For example, when an application with the following properties is run by using the switch, `--spring.profiles.active=prod`, the `proddb` and `prodmq` profiles are also activated: [source,yaml,indent=0] ---- @@ -1560,45 +1327,35 @@ activated: - prodmq ---- -NOTE: Remember that the `spring.profiles` property can be defined in a YAML document to -determine when this particular document is included in the configuration. See -<> for more details. +NOTE: Remember that the `spring.profiles` property can be defined in a YAML document to determine when this particular document is included in the configuration. +See <> for more details. [[boot-features-programmatically-setting-profiles]] === Programmatically Setting Profiles -You can programmatically set active profiles by calling -`SpringApplication.setAdditionalProfiles(...)` before your application runs. It is also -possible to activate profiles by using Spring's `ConfigurableEnvironment` interface. +You can programmatically set active profiles by calling `SpringApplication.setAdditionalProfiles(...)` before your application runs. +It is also possible to activate profiles by using Spring's `ConfigurableEnvironment` interface. [[boot-features-profile-specific-configuration]] === Profile-specific Configuration Files -Profile-specific variants of both `application.properties` (or `application.yml`) and -files referenced through `@ConfigurationProperties` are considered as files and loaded. +Profile-specific variants of both `application.properties` (or `application.yml`) and files referenced through `@ConfigurationProperties` are considered as files and loaded. See "<>" for details. [[boot-features-logging]] == Logging -Spring Boot uses https://commons.apache.org/logging[Commons Logging] for all internal -logging but leaves the underlying log implementation open. Default configurations are -provided for -{java-javadoc}/java/util/logging/package-summary.html[Java Util -Logging], https://logging.apache.org/log4j/2.x/[Log4J2], and -https://logback.qos.ch/[Logback]. In each case, loggers are pre-configured to use console -output with optional file output also available. +Spring Boot uses https://commons.apache.org/logging[Commons Logging] for all internal logging but leaves the underlying log implementation open. +Default configurations are provided for {java-javadoc}/java/util/logging/package-summary.html[Java Util Logging], https://logging.apache.org/log4j/2.x/[Log4J2], and https://logback.qos.ch/[Logback]. +In each case, loggers are pre-configured to use console output with optional file output also available. -By default, if you use the "`Starters`", Logback is used for logging. Appropriate Logback -routing is also included to ensure that dependent libraries that use Java Util Logging, -Commons Logging, Log4J, or SLF4J all work correctly. +By default, if you use the "`Starters`", Logback is used for logging. Appropriate Logback routing is also included to ensure that dependent libraries that use Java Util Logging, Commons Logging, Log4J, or SLF4J all work correctly. -TIP: There are a lot of logging frameworks available for Java. Do not worry if the above -list seems confusing. Generally, you do not need to change your logging dependencies and -the Spring Boot defaults work just fine. +TIP: There are a lot of logging frameworks available for Java. Do not worry if the above list seems confusing. +Generally, you do not need to change your logging dependencies and the Spring Boot defaults work just fine. @@ -1608,11 +1365,11 @@ The default log output from Spring Boot resembles the following example: [indent=0] ---- -2014-03-05 10:57:51.112 INFO 45469 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/7.0.52 -2014-03-05 10:57:51.253 INFO 45469 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext -2014-03-05 10:57:51.253 INFO 45469 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1358 ms -2014-03-05 10:57:51.698 INFO 45469 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/] -2014-03-05 10:57:51.702 INFO 45469 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*] +2019-03-05 10:57:51.112 INFO 45469 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet Engine: Apache Tomcat/7.0.52 +2019-03-05 10:57:51.253 INFO 45469 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext +2019-03-05 10:57:51.253 INFO 45469 --- [ost-startStop-1] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 1358 ms +2019-03-05 10:57:51.698 INFO 45469 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean : Mapping servlet: 'dispatcherServlet' to [/] +2019-03-05 10:57:51.702 INFO 45469 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean : Mapping filter: 'hiddenHttpMethodFilter' to: [/*] ---- The following items are output: @@ -1628,11 +1385,12 @@ The following items are output: NOTE: Logback does not have a `FATAL` level. It is mapped to `ERROR`. + [[boot-features-logging-console-output]] === Console Output -The default log configuration echoes messages to the console as they are written. By -default, `ERROR`-level, `WARN`-level, and `INFO`-level messages are logged. You can also -enable a "`debug`" mode by starting your application with a `--debug` flag. +The default log configuration echoes messages to the console as they are written. +By default, `ERROR`-level, `WARN`-level, and `INFO`-level messages are logged. +You can also enable a "`debug`" mode by starting your application with a `--debug` flag. [indent=0] ---- @@ -1641,25 +1399,21 @@ enable a "`debug`" mode by starting your application with a `--debug` flag. NOTE: You can also specify `debug=true` in your `application.properties`. -When the debug mode is enabled, a selection of core loggers (embedded container, -Hibernate, and Spring Boot) are configured to output more information. Enabling the debug -mode does _not_ configure your application to log all messages with `DEBUG` level. +When the debug mode is enabled, a selection of core loggers (embedded container, Hibernate, and Spring Boot) are configured to output more information. +Enabling the debug mode does _not_ configure your application to log all messages with `DEBUG` level. + +Alternatively, you can enable a "`trace`" mode by starting your application with a `--trace` flag (or `trace=true` in your `application.properties`). +Doing so enables trace logging for a selection of core loggers (embedded container, Hibernate schema generation, and the whole Spring portfolio). + -Alternatively, you can enable a "`trace`" mode by starting your application with a -`--trace` flag (or `trace=true` in your `application.properties`). Doing so enables trace -logging for a selection of core loggers (embedded container, Hibernate schema generation, -and the whole Spring portfolio). [[boot-features-logging-color-coded-output]] ==== Color-coded Output -If your terminal supports ANSI, color output is used to aid readability. You can set -`spring.output.ansi.enabled` to a -{dc-spring-boot}/ansi/AnsiOutput.Enabled.{dc-ext}[supported value] to override the auto -detection. +If your terminal supports ANSI, color output is used to aid readability. +You can set `spring.output.ansi.enabled` to a {dc-spring-boot}/ansi/AnsiOutput.Enabled.{dc-ext}[supported value] to override the auto-detection. -Color coding is configured by using the `%clr` conversion word. In its simplest form, the -converter colors the output according to the log level, as shown in the following -example: +Color coding is configured by using the `%clr` conversion word. +In its simplest form, the converter colors the output according to the log level, as shown in the following example: [source,indent=0] ---- @@ -1669,30 +1423,29 @@ example: The following table describes the mapping of log levels to colors: |=== -|Level | Color +| Level | Color -|`FATAL` +| `FATAL` | Red -|`ERROR` +| `ERROR` | Red -|`WARN` +| `WARN` | Yellow -|`INFO` +| `INFO` | Green -|`DEBUG` +| `DEBUG` | Green -|`TRACE` +| `TRACE` | Green |=== -Alternatively, you can specify the color or style that should be used by providing it as -an option to the conversion. For example, to make the text yellow, use the following -setting: +Alternatively, you can specify the color or style that should be used by providing it as an option to the conversion. +For example, to make the text yellow, use the following setting: [source,indent=0] ---- @@ -1709,58 +1462,54 @@ The following colors and styles are supported: * `red` * `yellow` + + [[boot-features-logging-file-output]] === File Output -By default, Spring Boot logs only to the console and does not write log files. If you -want to write log files in addition to the console output, you need to set a -`logging.file` or `logging.path` property (for example, in your -`application.properties`). +By default, Spring Boot logs only to the console and does not write log files. +If you want to write log files in addition to the console output, you need to set a `logging.file` or `logging.path` property (for example, in your `application.properties`). The following table shows how the `logging.*` properties can be used together: .Logging properties [cols="1,1,1,4"] |=== -|`logging.file` |`logging.path` |Example |Description +| `logging.file` | `logging.path` | Example | Description -|_(none)_ -|_(none)_ +| _(none)_ +| _(none)_ | -|Console only logging. +| Console only logging. -|Specific file -|_(none)_ -|`my.log` -|Writes to the specified log file. Names can be an exact location or relative to the -current directory. +| Specific file +| _(none)_ +| `my.log` +| Writes to the specified log file. + Names can be an exact location or relative to the current directory. -|_(none)_ -|Specific directory -|`/var/log` -|Writes `spring.log` to the specified directory. Names can be an exact location or -relative to the current directory. +| _(none)_ +| Specific directory +| `/var/log` +| Writes `spring.log` to the specified directory. + Names can be an exact location or relative to the current directory. |=== -Log files rotate when they reach 10 MB and, as with console output, `ERROR`-level, -`WARN`-level, and `INFO`-level messages are logged by default. Size limits can be changed -using the `logging.file.max-size` property. Previously rotated files are archived -indefinitely unless the `logging.file.max-history` property has been set. +Log files rotate when they reach 10 MB and, as with console output, `ERROR`-level, `WARN`-level, and `INFO`-level messages are logged by default. +Size limits can be changed using the `logging.file.max-size` property. +Previously rotated files are archived indefinitely unless the `logging.file.max-history` property has been set. -NOTE: The logging system is initialized early in the application lifecycle. Consequently, -logging properties are not found in property files loaded through `@PropertySource` -annotations. +NOTE: The logging system is initialized early in the application lifecycle. +Consequently, logging properties are not found in property files loaded through `@PropertySource` annotations. + +TIP: Logging properties are independent of the actual logging infrastructure. +As a result, specific configuration keys (such as `logback.configurationFile` for Logback) are not managed by spring Boot. -TIP: Logging properties are independent of the actual logging infrastructure. As a -result, specific configuration keys (such as `logback.configurationFile` for Logback) are -not managed by spring Boot. [[boot-features-custom-log-levels]] === Log Levels -All the supported logging systems can have the logger levels set in the Spring -`Environment` (for example, in `application.properties`) by using -`+logging.level.=+` where `level` is one of TRACE, DEBUG, INFO, WARN, -ERROR, FATAL, or OFF. The `root` logger can be configured by using `logging.level.root`. +All the supported logging systems can have the logger levels set in the Spring `Environment` (for example, in `application.properties`) by using `+logging.level.=+` where `level` is one of TRACE, DEBUG, INFO, WARN, ERROR, FATAL, or OFF. +The `root` logger can be configured by using `logging.level.root`. The following example shows potential logging settings in `application.properties`: @@ -1775,138 +1524,125 @@ The following example shows potential logging settings in `application.propertie [[boot-features-custom-log-groups]] === Log Groups -It's often useful to be able to group related loggers together so that they can all be -configured at the same time. For example, you might commonly change the logging levels for -_all_ Tomcat related loggers, but you can't easily remember top level packages. +It's often useful to be able to group related loggers together so that they can all be configured at the same time. +For example, you might commonly change the logging levels for _all_ Tomcat related loggers, but you can't easily remember top level packages. -To help with this, Spring Boot allows you to define logging groups in your Spring -`Environment`. For example, here's how you could define a "`tomcat`" group by adding -it to your `application.properties`: +To help with this, Spring Boot allows you to define logging groups in your Spring `Environment`. +For example, here's how you could define a "`tomcat`" group by adding it to your `application.properties`: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- logging.group.tomcat=org.apache.catalina, org.apache.coyote, org.apache.tomcat ---- -Once defined, you can change the level for all the loggers in the group with a single -line: +Once defined, you can change the level for all the loggers in the group with a single line: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- logging.level.tomcat=TRACE ---- -Spring Boot includes the following pre-defined logging groups that can be used -out-of-the-box: +Spring Boot includes the following pre-defined logging groups that can be used out-of-the-box: [cols="1,4"] |=== -|Name |Loggers +| Name | Loggers -|web -|`org.springframework.core.codec`, `org.springframework.http`, `org.springframework.web` - -|sql -|`org.springframework.jdbc.core`, `org.hibernate.SQL` +| web +| `org.springframework.core.codec`, `org.springframework.http`, `org.springframework.web` +| sql +| `org.springframework.jdbc.core`, `org.hibernate.SQL` |=== [[boot-features-custom-log-configuration]] === Custom Log Configuration -The various logging systems can be activated by including the appropriate libraries on -the classpath and can be further customized by providing a suitable configuration file in -the root of the classpath or in a location specified by the following Spring `Environment` -property: `logging.config`. +The various logging systems can be activated by including the appropriate libraries on the classpath and can be further customized by providing a suitable configuration file in the root of the classpath or in a location specified by the following Spring `Environment` property: `logging.config`. -You can force Spring Boot to use a particular logging system by using the -`org.springframework.boot.logging.LoggingSystem` system property. The value should be the -fully qualified class name of a `LoggingSystem` implementation. You can also disable -Spring Boot's logging configuration entirely by using a value of `none`. +You can force Spring Boot to use a particular logging system by using the `org.springframework.boot.logging.LoggingSystem` system property. +The value should be the fully qualified class name of a `LoggingSystem` implementation. +You can also disable Spring Boot's logging configuration entirely by using a value of `none`. -NOTE: Since logging is initialized *before* the `ApplicationContext` is created, it is -not possible to control logging from `@PropertySources` in Spring `@Configuration` files. +NOTE: Since logging is initialized *before* the `ApplicationContext` is created, it is not possible to control logging from `@PropertySources` in Spring `@Configuration` files. The only way to change the logging system or disable it entirely is via System properties. Depending on your logging system, the following files are loaded: |=== -|Logging System |Customization +| Logging System | Customization -|Logback -|`logback-spring.xml`, `logback-spring.groovy`, `logback.xml`, or `logback.groovy` +| Logback +| `logback-spring.xml`, `logback-spring.groovy`, `logback.xml`, or `logback.groovy` -|Log4j2 -|`log4j2-spring.xml` or `log4j2.xml` +| Log4j2 +| `log4j2-spring.xml` or `log4j2.xml` -|JDK (Java Util Logging) -|`logging.properties` +| JDK (Java Util Logging) +| `logging.properties` |=== -NOTE: When possible, we recommend that you use the `-spring` variants for your logging -configuration (for example, `logback-spring.xml` rather than `logback.xml`). If you use -standard configuration locations, Spring cannot completely control log initialization. +NOTE: When possible, we recommend that you use the `-spring` variants for your logging configuration (for example, `logback-spring.xml` rather than `logback.xml`). +If you use standard configuration locations, Spring cannot completely control log initialization. -WARNING: There are known classloading issues with Java Util Logging that cause problems -when running from an 'executable jar'. We recommend that you avoid it when running from -an 'executable jar' if at all possible. +WARNING: There are known classloading issues with Java Util Logging that cause problems when running from an 'executable jar'. +We recommend that you avoid it when running from an 'executable jar' if at all possible. -To help with the customization, some other properties are transferred from the Spring -`Environment` to System properties, as described in the following table: +To help with the customization, some other properties are transferred from the Spring `Environment` to System properties, as described in the following table: |=== -|Spring Environment |System Property |Comments +| Spring Environment | System Property | Comments -|`logging.exception-conversion-word` -|`LOG_EXCEPTION_CONVERSION_WORD` -|The conversion word used when logging exceptions. +| `logging.exception-conversion-word` +| `LOG_EXCEPTION_CONVERSION_WORD` +| The conversion word used when logging exceptions. -|`logging.file` -|`LOG_FILE` -|If defined, it is used in the default log configuration. +| `logging.file` +| `LOG_FILE` +| If defined, it is used in the default log configuration. -|`logging.file.max-size` -|`LOG_FILE_MAX_SIZE` -|Maximum log file size (if LOG_FILE enabled). (Only supported with the default Logback -setup.) +| `logging.file.max-size` +| `LOG_FILE_MAX_SIZE` +| Maximum log file size (if LOG_FILE enabled). + (Only supported with the default Logback setup.) -|`logging.file.max-history` -|`LOG_FILE_MAX_HISTORY` -|Maximum number of archive log files to keep (if LOG_FILE enabled). (Only supported with -the default Logback setup.) +| `logging.file.max-history` +| `LOG_FILE_MAX_HISTORY` +| Maximum number of archive log files to keep (if LOG_FILE enabled). + (Only supported with the default Logback setup.) -|`logging.path` -|`LOG_PATH` -|If defined, it is used in the default log configuration. +| `logging.path` +| `LOG_PATH` +| If defined, it is used in the default log configuration. -|`logging.pattern.console` -|`CONSOLE_LOG_PATTERN` -|The log pattern to use on the console (stdout). (Only supported with the default Logback -setup.) +| `logging.pattern.console` +| `CONSOLE_LOG_PATTERN` +| The log pattern to use on the console (stdout). + (Only supported with the default Logback setup.) -|`logging.pattern.dateformat` -|`LOG_DATEFORMAT_PATTERN` -|Appender pattern for log date format. (Only supported with the default Logback setup.) +| `logging.pattern.dateformat` +| `LOG_DATEFORMAT_PATTERN` +| Appender pattern for log date format. + (Only supported with the default Logback setup.) -|`logging.pattern.file` -|`FILE_LOG_PATTERN` -|The log pattern to use in a file (if `LOG_FILE` is enabled). (Only supported with the -default Logback setup.) +| `logging.pattern.file` +| `FILE_LOG_PATTERN` +| The log pattern to use in a file (if `LOG_FILE` is enabled). + (Only supported with the default Logback setup.) -|`logging.pattern.level` -|`LOG_LEVEL_PATTERN` -|The format to use when rendering the log level (default `%5p`). (Only supported with the -default Logback setup.) +| `logging.pattern.level` +| `LOG_LEVEL_PATTERN` +| The format to use when rendering the log level (default `%5p`). + (Only supported with the default Logback setup.) -|`PID` -|`PID` -|The current process ID (discovered if possible and when not already defined as an OS -environment variable). +| `PID` +| `PID` +| The current process ID (discovered if possible and when not already defined as an OS environment variable). |=== -All the supported logging systems can consult System properties when parsing their -configuration files. See the default configurations in `spring-boot.jar` for examples: +All the supported logging systems can consult System properties when parsing their configuration files. +See the default configurations in `spring-boot.jar` for examples: * {github-code}/spring-boot-project/spring-boot/src/main/resources/org/springframework/boot/logging/logback/defaults.xml[Logback] * {github-code}/spring-boot-project/spring-boot/src/main/resources/org/springframework/boot/logging/log4j2/log4j2.xml[Log4j 2] @@ -1914,23 +1650,19 @@ configuration files. See the default configurations in `spring-boot.jar` for ex [TIP] ==== -If you want to use a placeholder in a logging property, you should use -<> and not -the syntax of the underlying framework. Notably, if you use Logback, you should use `:` -as the delimiter between a property name and its default value and not use `:-`. +If you want to use a placeholder in a logging property, you should use <> and not the syntax of the underlying framework. +Notably, if you use Logback, you should use `:` as the delimiter between a property name and its default value and not use `:-`. ==== [TIP] ==== +You can add MDC and other ad-hoc content to log lines by overriding only the `LOG_LEVEL_PATTERN` (or `logging.pattern.level` with Logback). +For example, if you use `logging.pattern.level=user:%X\{user} %5p`, then the default log format contains an MDC entry for "user", if it exists, as shown in the following example. -You can add MDC and other ad-hoc content to log lines by overriding only the -`LOG_LEVEL_PATTERN` (or `logging.pattern.level` with Logback). For example, if you use -`logging.pattern.level=user:%X\{user} %5p`, then the default log format contains an MDC -entry for "user", if it exists, as shown in the following example. - +[indent=0] ---- -2015-09-30 12:30:04.031 user:someone INFO 22174 --- [ nio-8080-exec-0] demo.Controller -Handling authenticated request + 2019-08-30 12:30:04.031 user:someone INFO 22174 --- [ nio-8080-exec-0] demo.Controller + Handling authenticated request ---- ==== @@ -1938,36 +1670,31 @@ Handling authenticated request [[boot-features-logback-extensions]] === Logback Extensions -Spring Boot includes a number of extensions to Logback that can help with advanced -configuration. You can use these extensions in your `logback-spring.xml` configuration -file. +Spring Boot includes a number of extensions to Logback that can help with advanced configuration. +You can use these extensions in your `logback-spring.xml` configuration file. -NOTE: Because the standard `logback.xml` configuration file is loaded too early, you -cannot use extensions in it. You need to either use `logback-spring.xml` or define a -`logging.config` property. +NOTE: Because the standard `logback.xml` configuration file is loaded too early, you cannot use extensions in it. +You need to either use `logback-spring.xml` or define a `logging.config` property. -WARNING: The extensions cannot be used with Logback's -https://logback.qos.ch/manual/configuration.html#autoScan[configuration scanning]. If you -attempt to do so, making changes to the configuration file results in an error similar to -one of the following being logged: +WARNING: The extensions cannot be used with Logback's https://logback.qos.ch/manual/configuration.html#autoScan[configuration scanning]. +If you attempt to do so, making changes to the configuration file results in an error similar to one of the following being logged: +[indent=0] ---- -ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProperty], current ElementPath is [[configuration][springProperty]] -ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProfile], current ElementPath is [[configuration][springProfile]] + ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProperty], current ElementPath is [[configuration][springProperty]] + ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProfile], current ElementPath is [[configuration][springProfile]] ---- ==== Profile-specific Configuration -The `` tag lets you optionally include or exclude sections of -configuration based on the active Spring profiles. Profile sections are supported -anywhere within the `` element. Use the `name` attribute to specify which -profile accepts the configuration. The `` tag can contain a simple profile -name (for example `staging`) or a profile expression. A profile expression allows for more -complicated profile logic to be expressed, for example -`production & (eu-central | eu-west)`. Check the -{spring-reference}core.html#beans-definition-profiles-java[reference guide] for more -details. The following listing shows three sample profiles: +The `` tag lets you optionally include or exclude sections of configuration based on the active Spring profiles. +Profile sections are supported anywhere within the `` element. +Use the `name` attribute to specify which profile accepts the configuration. +The `` tag can contain a simple profile name (for example `staging`) or a profile expression. +A profile expression allows for more complicated profile logic to be expressed, for example `production & (eu-central | eu-west)`. +Check the {spring-reference}core.html#beans-definition-profiles-java[reference guide] for more details. +The following listing shows three sample profiles: [source,xml,indent=0] ---- @@ -1987,15 +1714,13 @@ details. The following listing shows three sample profiles: ==== Environment Properties -The `` tag lets you expose properties from the Spring `Environment` for -use within Logback. Doing so can be useful if you want to access values from your -`application.properties` file in your Logback configuration. The tag works in a similar -way to Logback's standard `` tag. However, rather than specifying a direct -`value`, you specify the `source` of the property (from the `Environment`). If you need -to store the property somewhere other than in `local` scope, you can use the `scope` -attribute. If you need a fallback value (in case the property is not set in the -`Environment`), you can use the `defaultValue` attribute. The following example shows how -to expose properties for use within Logback: +The `` tag lets you expose properties from the Spring `Environment` for use within Logback. +Doing so can be useful if you want to access values from your `application.properties` file in your Logback configuration. +The tag works in a similar way to Logback's standard `` tag. +However, rather than specifying a direct `value`, you specify the `source` of the property (from the `Environment`). +If you need to store the property somewhere other than in `local` scope, you can use the `scope` attribute. +If you need a fallback value (in case the property is not set in the `Environment`), you can use the `defaultValue` attribute. +The following example shows how to expose properties for use within Logback: [source,xml,indent=0] ---- @@ -2014,18 +1739,14 @@ However, properties can be added to the `Environment` by using the relaxed rules [[boot-features-internationalization]] == Internationalization -Spring Boot supports localized messages so that your application can cater to users -of different language preferences. By default, Spring Boot looks for the presence of -a `messages` resource bundle at the root of the classpath. +Spring Boot supports localized messages so that your application can cater to users of different language preferences. +By default, Spring Boot looks for the presence of a `messages` resource bundle at the root of the classpath. -NOTE: The auto-configuration applies when the default properties file for the configured -resource bundle is available (i.e. `messages.properties` by default). If your resource -bundle contains only language-specific properties files, you are required to add the -default. If no properties file is found that matches any of the configured base names, -there will be no auto-configured `MessageSource`. +NOTE: The auto-configuration applies when the default properties file for the configured resource bundle is available (i.e. `messages.properties` by default). +If your resource bundle contains only language-specific properties files, you are required to add the default. +If no properties file is found that matches any of the configured base names, there will be no auto-configured `MessageSource`. -The basename of the resource bundle as well as several other attributes can be configured -using the `spring.messages` namespace, as shown in the following example: +The basename of the resource bundle as well as several other attributes can be configured using the `spring.messages` namespace, as shown in the following example: [source,properties,indent=0] ---- @@ -2033,12 +1754,9 @@ using the `spring.messages` namespace, as shown in the following example: spring.messages.fallback-to-system-locale=false ---- -TIP: `spring.messages.basename` supports comma-separated list of locations, either a -package qualifier or a resource resolved from the classpath root. - -See {sc-spring-boot-autoconfigure}/context/MessageSourceProperties.{sc-ext}[ -`MessageSourceProperties`] for more supported options. +TIP: `spring.messages.basename` supports comma-separated list of locations, either a package qualifier or a resource resolved from the classpath root. +See {sc-spring-boot-autoconfigure}/context/MessageSourceProperties.{sc-ext}[`MessageSourceProperties`] for more supported options. @@ -2056,50 +1774,44 @@ Jackson is the preferred and default library. [[boot-features-json-jackson]] === Jackson -Auto-configuration for Jackson is provided and Jackson is part of -`spring-boot-starter-json`. When Jackson is on the classpath an `ObjectMapper` -bean is automatically configured. Several configuration properties are provided for -<>. +Auto-configuration for Jackson is provided and Jackson is part of `spring-boot-starter-json`. +When Jackson is on the classpath an `ObjectMapper` bean is automatically configured. +Several configuration properties are provided for <>. [[boot-features-json-gson]] === Gson -Auto-configuration for Gson is provided. When Gson is on the classpath a `Gson` bean is -automatically configured. Several `+spring.gson.*+` configuration properties are -provided for customizing the configuration. To take more control, one or more -`GsonBuilderCustomizer` beans can be used. +Auto-configuration for Gson is provided. +When Gson is on the classpath a `Gson` bean is automatically configured. +Several `+spring.gson.*+` configuration properties are provided for customizing the configuration. +To take more control, one or more `GsonBuilderCustomizer` beans can be used. [[boot-features-json-json-b]] === JSON-B -Auto-configuration for JSON-B is provided. When the JSON-B API and an implementation are -on the classpath a `Jsonb` bean will be automatically configured. The preferred JSON-B -implementation is Apache Johnzon for which dependency management is provided. +Auto-configuration for JSON-B is provided. +When the JSON-B API and an implementation are on the classpath a `Jsonb` bean will be automatically configured. +The preferred JSON-B implementation is Apache Johnzon for which dependency management is provided. [[boot-features-developing-web-applications]] == Developing Web Applications -Spring Boot is well suited for web application development. You can create a -self-contained HTTP server by using embedded Tomcat, Jetty, Undertow, or Netty. Most web -applications use the `spring-boot-starter-web` module to get up and running quickly. You -can also choose to build reactive web applications by using the -`spring-boot-starter-webflux` module. +Spring Boot is well suited for web application development. +You can create a self-contained HTTP server by using embedded Tomcat, Jetty, Undertow, or Netty. +Most web applications use the `spring-boot-starter-web` module to get up and running quickly. +You can also choose to build reactive web applications by using the `spring-boot-starter-webflux` module. -If you have not yet developed a Spring Boot web application, you can follow the -"Hello World!" example in the -_<>_ section. +If you have not yet developed a Spring Boot web application, you can follow the "Hello World!" example in the _<>_ section. [[boot-features-spring-mvc]] === The "`Spring Web MVC Framework`" -The {spring-reference}web.html#mvc[Spring Web MVC framework] (often referred to as simply -"`Spring MVC`") is a rich "`model view controller`" web framework. Spring MVC lets you -create special `@Controller` or `@RestController` beans to handle incoming HTTP requests. +The {spring-reference}web.html#mvc[Spring Web MVC framework] (often referred to as simply "`Spring MVC`") is a rich "`model view controller`" web framework. +Spring MVC lets you create special `@Controller` or `@RestController` beans to handle incoming HTTP requests. Methods in your controller are mapped to HTTP by using `@RequestMapping` annotations. The following code shows a typical `@RestController` that serves JSON data: @@ -2128,55 +1840,39 @@ The following code shows a typical `@RestController` that serves JSON data: } ---- -Spring MVC is part of the core Spring Framework, and detailed information is available in -the {spring-reference}web.html#mvc[reference documentation]. There are also several -guides that cover Spring MVC available at https://spring.io/guides. +Spring MVC is part of the core Spring Framework, and detailed information is available in the {spring-reference}web.html#mvc[reference documentation]. +There are also several guides that cover Spring MVC available at https://spring.io/guides. [[boot-features-spring-mvc-auto-configuration]] ==== Spring MVC Auto-configuration -Spring Boot provides auto-configuration for Spring MVC that works well with most -applications. +Spring Boot provides auto-configuration for Spring MVC that works well with most applications. The auto-configuration adds the following features on top of Spring's defaults: * Inclusion of `ContentNegotiatingViewResolver` and `BeanNameViewResolver` beans. -* Support for serving static resources, including support for WebJars (covered -<>)). +* Support for serving static resources, including support for WebJars (covered <>)). * Automatic registration of `Converter`, `GenericConverter`, and `Formatter` beans. -* Support for `HttpMessageConverters` (covered -<>). -* Automatic registration of `MessageCodesResolver` (covered -<>). +* Support for `HttpMessageConverters` (covered <>). +* Automatic registration of `MessageCodesResolver` (covered <>). * Static `index.html` support. -* Custom `Favicon` support (covered <>). -* Automatic use of a `ConfigurableWebBindingInitializer` bean (covered -<>). +* Custom `Favicon` support (covered <>). +* Automatic use of a `ConfigurableWebBindingInitializer` bean (covered <>). -If you want to keep Spring Boot MVC features and you want to add additional -{spring-reference}web.html#mvc[MVC configuration] (interceptors, formatters, view -controllers, and other features), you can add your own `@Configuration` class of type -`WebMvcConfigurer` but *without* `@EnableWebMvc`. If you wish to provide custom -instances of `RequestMappingHandlerMapping`, `RequestMappingHandlerAdapter`, or -`ExceptionHandlerExceptionResolver`, you can declare a `WebMvcRegistrationsAdapter` -instance to provide such components. +If you want to keep Spring Boot MVC features and you want to add additional {spring-reference}web.html#mvc[MVC configuration] (interceptors, formatters, view controllers, and other features), you can add your own `@Configuration` class of type `WebMvcConfigurer` but *without* `@EnableWebMvc`. +If you wish to provide custom instances of `RequestMappingHandlerMapping`, `RequestMappingHandlerAdapter`, or `ExceptionHandlerExceptionResolver`, you can declare a `WebMvcRegistrationsAdapter` instance to provide such components. -If you want to take complete control of Spring MVC, you can add your own `@Configuration` -annotated with `@EnableWebMvc`. +If you want to take complete control of Spring MVC, you can add your own `@Configuration` annotated with `@EnableWebMvc`. [[boot-features-spring-mvc-message-converters]] ==== HttpMessageConverters -Spring MVC uses the `HttpMessageConverter` interface to convert HTTP requests and -responses. Sensible defaults are included out of the box. For example, objects can be -automatically converted to JSON (by using the Jackson library) or XML (by using the -Jackson XML extension, if available, or by using JAXB if the Jackson XML extension is not -available). By default, strings are encoded in `UTF-8`. +Spring MVC uses the `HttpMessageConverter` interface to convert HTTP requests and responses. +Sensible defaults are included out of the box. For example, objects can be automatically converted to JSON (by using the Jackson library) or XML (by using the Jackson XML extension, if available, or by using JAXB if the Jackson XML extension is not available). +By default, strings are encoded in `UTF-8`. -If you need to add or customize converters, you can use Spring Boot's -`HttpMessageConverters` class, as shown in the following listing: +If you need to add or customize converters, you can use Spring Boot's `HttpMessageConverters` class, as shown in the following listing: [source,java,indent=0] ---- @@ -2197,22 +1893,18 @@ If you need to add or customize converters, you can use Spring Boot's } ---- -Any `HttpMessageConverter` bean that is present in the context is added to the list of -converters. You can also override default converters in the same way. +Any `HttpMessageConverter` bean that is present in the context is added to the list of converters. +You can also override default converters in the same way. [[boot-features-json-components]] ==== Custom JSON Serializers and Deserializers -If you use Jackson to serialize and deserialize JSON data, you might want to write your -own `JsonSerializer` and `JsonDeserializer` classes. Custom serializers are usually -https://github.com/FasterXML/jackson-docs/wiki/JacksonHowToCustomSerializers[registered with Jackson through -a module], but Spring Boot provides an alternative `@JsonComponent` annotation that makes -it easier to directly register Spring Beans. +If you use Jackson to serialize and deserialize JSON data, you might want to write your own `JsonSerializer` and `JsonDeserializer` classes. +Custom serializers are usually https://github.com/FasterXML/jackson-docs/wiki/JacksonHowToCustomSerializers[registered with Jackson through a module], but Spring Boot provides an alternative `@JsonComponent` annotation that makes it easier to directly register Spring Beans. -You can use the `@JsonComponent` annotation directly on `JsonSerializer` or -`JsonDeserializer` implementations. You can also use it on classes that contain -serializers/deserializers as inner classes, as shown in the following example: +You can use the `@JsonComponent` annotation directly on `JsonSerializer` or `JsonDeserializer` implementations. +You can also use it on classes that contain serializers/deserializers as inner classes, as shown in the following example: [source,java,indent=0] ---- @@ -2235,83 +1927,55 @@ serializers/deserializers as inner classes, as shown in the following example: } ---- -All `@JsonComponent` beans in the `ApplicationContext` are automatically registered with -Jackson. Because `@JsonComponent` is meta-annotated with `@Component`, the usual -component-scanning rules apply. +All `@JsonComponent` beans in the `ApplicationContext` are automatically registered with Jackson. +Because `@JsonComponent` is meta-annotated with `@Component`, the usual component-scanning rules apply. -Spring Boot also provides -{sc-spring-boot}/jackson/JsonObjectSerializer.{sc-ext}[`JsonObjectSerializer`] and -{sc-spring-boot}/jackson/JsonObjectDeserializer.{sc-ext}[`JsonObjectDeserializer`] base -classes that provide useful alternatives to the standard Jackson versions when -serializing objects. See -{dc-spring-boot}/jackson/JsonObjectSerializer.{dc-ext}[`JsonObjectSerializer`] -and {dc-spring-boot}/jackson/JsonObjectDeserializer.{dc-ext}[`JsonObjectDeserializer`] in -the Javadoc for details. +Spring Boot also provides {sc-spring-boot}/jackson/JsonObjectSerializer.{sc-ext}[`JsonObjectSerializer`] and {sc-spring-boot}/jackson/JsonObjectDeserializer.{sc-ext}[`JsonObjectDeserializer`] base classes that provide useful alternatives to the standard Jackson versions when serializing objects. +See {dc-spring-boot}/jackson/JsonObjectSerializer.{dc-ext}[`JsonObjectSerializer`] and {dc-spring-boot}/jackson/JsonObjectDeserializer.{dc-ext}[`JsonObjectDeserializer`] in the Javadoc for details. [[boot-features-spring-message-codes]] ==== MessageCodesResolver -Spring MVC has a strategy for generating error codes for rendering error messages from -binding errors: `MessageCodesResolver`. If you set the -`spring.mvc.message-codes-resolver.format` property `PREFIX_ERROR_CODE` or -`POSTFIX_ERROR_CODE`, Spring Boot creates one for you (see the enumeration in -{spring-javadoc}/validation/DefaultMessageCodesResolver.Format.{dc-ext}[`DefaultMessageCodesResolver.Format`]). +Spring MVC has a strategy for generating error codes for rendering error messages from binding errors: `MessageCodesResolver`. +If you set the `spring.mvc.message-codes-resolver.format` property `PREFIX_ERROR_CODE` or `POSTFIX_ERROR_CODE`, Spring Boot creates one for you (see the enumeration in {spring-javadoc}/validation/DefaultMessageCodesResolver.Format.{dc-ext}[`DefaultMessageCodesResolver.Format`]). [[boot-features-spring-mvc-static-content]] ==== Static Content -By default, Spring Boot serves static content from a directory called `/static` (or -`/public` or `/resources` or `/META-INF/resources`) in the classpath or from the root of -the `ServletContext`. It uses the `ResourceHttpRequestHandler` from Spring MVC so that -you can modify that behavior by adding your own `WebMvcConfigurer` and overriding the -`addResourceHandlers` method. +By default, Spring Boot serves static content from a directory called `/static` (or `/public` or `/resources` or `/META-INF/resources`) in the classpath or from the root of the `ServletContext`. +It uses the `ResourceHttpRequestHandler` from Spring MVC so that you can modify that behavior by adding your own `WebMvcConfigurer` and overriding the `addResourceHandlers` method. -In a stand-alone web application, the default servlet from the container is also enabled -and acts as a fallback, serving content from the root of the `ServletContext` if Spring -decides not to handle it. Most of the time, this does not happen (unless you modify the -default MVC configuration), because Spring can always handle requests through the -`DispatcherServlet`. +In a stand-alone web application, the default servlet from the container is also enabled and acts as a fallback, serving content from the root of the `ServletContext` if Spring decides not to handle it. +Most of the time, this does not happen (unless you modify the default MVC configuration), because Spring can always handle requests through the `DispatcherServlet`. -By default, resources are mapped on `+/**+`, but you can tune that with the -`spring.mvc.static-path-pattern` property. For instance, relocating all resources to -`/resources/**` can be achieved as follows: +By default, resources are mapped on `+/**+`, but you can tune that with the `spring.mvc.static-path-pattern` property. +For instance, relocating all resources to `/resources/**` can be achieved as follows: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- spring.mvc.static-path-pattern=/resources/** ---- -You can also customize the static resource locations by using the -`spring.resources.static-locations` property (replacing the default values with a list of -directory locations). The root Servlet context path, `"/"`, is automatically added as a -location as well. +You can also customize the static resource locations by using the `spring.resources.static-locations` property (replacing the default values with a list of directory locations). +The root Servlet context path, `"/"`, is automatically added as a location as well. -In addition to the "`standard`" static resource locations mentioned earlier, a special -case is made for https://www.webjars.org/[Webjars content]. Any resources with a path in -`+/webjars/**+` are served from jar files if they are packaged in the Webjars format. +In addition to the "`standard`" static resource locations mentioned earlier, a special case is made for https://www.webjars.org/[Webjars content]. +Any resources with a path in `+/webjars/**+` are served from jar files if they are packaged in the Webjars format. TIP: Do not use the `src/main/webapp` directory if your application is packaged as a jar. -Although this directory is a common standard, it works *only* with war packaging, and it -is silently ignored by most build tools if you generate a jar. +Although this directory is a common standard, it works *only* with war packaging, and it is silently ignored by most build tools if you generate a jar. -Spring Boot also supports the advanced resource handling features provided by Spring MVC, -allowing use cases such as cache-busting static resources or using version agnostic URLs -for Webjars. +Spring Boot also supports the advanced resource handling features provided by Spring MVC, allowing use cases such as cache-busting static resources or using version agnostic URLs for Webjars. To use version agnostic URLs for Webjars, add the `webjars-locator-core` dependency. -Then declare your Webjar. Using jQuery as an example, adding -`"/webjars/jquery/jquery.min.js"` results in -`"/webjars/jquery/x.y.z/jquery.min.js"`. where `x.y.z` is the Webjar version. +Then declare your Webjar. Using jQuery as an example, adding `"/webjars/jquery/jquery.min.js"` results in `"/webjars/jquery/x.y.z/jquery.min.js"` where `x.y.z` is the Webjar version. -NOTE: If you use JBoss, you need to declare the `webjars-locator-jboss-vfs` -dependency instead of the `webjars-locator-core`. Otherwise, all Webjars resolve as a -`404`. +NOTE: If you use JBoss, you need to declare the `webjars-locator-jboss-vfs` dependency instead of the `webjars-locator-core`. +Otherwise, all Webjars resolve as a `404`. -To use cache busting, the following configuration configures a cache busting solution for -all static resources, effectively adding a content hash, such as -``, in URLs: +To use cache busting, the following configuration configures a cache busting solution for all static resources, effectively adding a content hash, such as ``, in URLs: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2319,17 +1983,12 @@ all static resources, effectively adding a content hash, such as spring.resources.chain.strategy.content.paths=/** ---- -NOTE: Links to resources are rewritten in templates at runtime, thanks to a -`ResourceUrlEncodingFilter` that is auto-configured for Thymeleaf and FreeMarker. You -should manually declare this filter when using JSPs. Other template engines are currently -not automatically supported but can be with custom template macros/helpers and the use of -the -{spring-javadoc}/web/servlet/resource/ResourceUrlProvider.{dc-ext}[`ResourceUrlProvider`]. +NOTE: Links to resources are rewritten in templates at runtime, thanks to a `ResourceUrlEncodingFilter` that is auto-configured for Thymeleaf and FreeMarker. +You should manually declare this filter when using JSPs. +Other template engines are currently not automatically supported but can be with custom template macros/helpers and the use of the {spring-javadoc}/web/servlet/resource/ResourceUrlProvider.{dc-ext}[`ResourceUrlProvider`]. -When loading resources dynamically with, for example, a JavaScript module loader, -renaming files is not an option. That is why other strategies are also supported and can -be combined. A "fixed" strategy adds a static version string in the URL without changing -the file name, as shown in the following example: +When loading resources dynamically with, for example, a JavaScript module loader, renaming files is not an option. +That is why other strategies are also supported and can be combined. A "fixed" strategy adds a static version string in the URL without changing the file name, as shown in the following example: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2340,57 +1999,40 @@ the file name, as shown in the following example: spring.resources.chain.strategy.fixed.version=v12 ---- -With this configuration, JavaScript modules located under `"/js/lib/"` use a fixed -versioning strategy (`"/v12/js/lib/mymodule.js"`), while other resources still use the -content one (``). +With this configuration, JavaScript modules located under `"/js/lib/"` use a fixed versioning strategy (`"/v12/js/lib/mymodule.js"`), while other resources still use the content one (``). -See {sc-spring-boot-autoconfigure}/web/ResourceProperties.{sc-ext}[`ResourceProperties`] -for more supported options. +See {sc-spring-boot-autoconfigure}/web/ResourceProperties.{sc-ext}[`ResourceProperties`] for more supported options. [TIP] ==== -This feature has been thoroughly described in a dedicated -https://spring.io/blog/2014/07/24/spring-framework-4-1-handling-static-web-resources[blog -post] and in Spring Framework's -{spring-reference}web.html#mvc-config-static-resources[reference documentation]. +This feature has been thoroughly described in a dedicated https://spring.io/blog/2014/07/24/spring-framework-4-1-handling-static-web-resources[blog post] and in Spring Framework's {spring-reference}web.html#mvc-config-static-resources[reference documentation]. ==== [[boot-features-spring-mvc-welcome-page]] ==== Welcome Page -Spring Boot supports both static and templated welcome pages. It first looks for an -`index.html` file in the configured static content locations. If one is not found, it -then looks for an `index` template. If either is found, it is automatically used as the -welcome page of the application. +Spring Boot supports both static and templated welcome pages. It first looks for an `index.html` file in the configured static content locations. +If one is not found, it then looks for an `index` template. +If either is found, it is automatically used as the welcome page of the application. [[boot-features-spring-mvc-favicon]] ==== Custom Favicon -Spring Boot looks for a `favicon.ico` in the configured static content locations and the -root of the classpath (in that order). If such a file is present, it is automatically -used as the favicon of the application. +Spring Boot looks for a `favicon.ico` in the configured static content locations and the root of the classpath (in that order). +If such a file is present, it is automatically used as the favicon of the application. [[boot-features-spring-mvc-pathmatch]] ==== Path Matching and Content Negotiation -Spring MVC can map incoming HTTP requests to handlers by looking at the request path and -matching it to the mappings defined in your application (for example, `@GetMapping` -annotations on Controller methods). +Spring MVC can map incoming HTTP requests to handlers by looking at the request path and matching it to the mappings defined in your application (for example, `@GetMapping` annotations on Controller methods). -Spring Boot chooses to disable suffix pattern matching by default, which means that -requests like `"GET /projects/spring-boot.json"` won't be matched to -`@GetMapping("/projects/spring-boot")` mappings. -This is considered as a -{spring-reference}web.html#mvc-ann-requestmapping-suffix-pattern-match[best practice -for Spring MVC applications]. This feature was mainly useful in the past for HTTP -clients which did not send proper "Accept" request headers; we needed to make sure -to send the correct Content Type to the client. Nowadays, Content Negotiation -is much more reliable. +Spring Boot chooses to disable suffix pattern matching by default, which means that requests like `"GET /projects/spring-boot.json"` won't be matched to `@GetMapping("/projects/spring-boot")` mappings. +This is considered as a {spring-reference}web.html#mvc-ann-requestmapping-suffix-pattern-match[best practice for Spring MVC applications]. +This feature was mainly useful in the past for HTTP clients which did not send proper "Accept" request headers; we needed to make sure to send the correct Content Type to the client. +Nowadays, Content Negotiation is much more reliable. -There are other ways to deal with HTTP clients that don't consistently send proper -"Accept" request headers. Instead of using suffix matching, we can use a query -parameter to ensure that requests like `"GET /projects/spring-boot?format=json"` -will be mapped to `@GetMapping("/projects/spring-boot")`: +There are other ways to deal with HTTP clients that don't consistently send proper "Accept" request headers. +Instead of using suffix matching, we can use a query parameter to ensure that requests like `"GET /projects/spring-boot?format=json"` will be mapped to `@GetMapping("/projects/spring-boot")`: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2403,8 +2045,7 @@ will be mapped to `@GetMapping("/projects/spring-boot")`: spring.mvc.contentnegotiation.media-types.markdown=text/markdown ---- -If you understand the caveats and would still like your application to use -suffix pattern matching, the following configuration is required: +If you understand the caveats and would still like your application to use suffix pattern matching, the following configuration is required: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2412,8 +2053,7 @@ suffix pattern matching, the following configuration is required: spring.mvc.pathmatch.use-suffix-pattern=true ---- -Alternatively, rather than open all suffix patterns, it's more secure to just support -registered suffix patterns: +Alternatively, rather than open all suffix patterns, it's more secure to just support registered suffix patterns: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2428,18 +2068,16 @@ registered suffix patterns: [[boot-features-spring-mvc-web-binding-initializer]] ==== ConfigurableWebBindingInitializer -Spring MVC uses a `WebBindingInitializer` to initialize a `WebDataBinder` for a -particular request. If you create your own `ConfigurableWebBindingInitializer` `@Bean`, -Spring Boot automatically configures Spring MVC to use it. +Spring MVC uses a `WebBindingInitializer` to initialize a `WebDataBinder` for a particular request. +If you create your own `ConfigurableWebBindingInitializer` `@Bean`, Spring Boot automatically configures Spring MVC to use it. [[boot-features-spring-mvc-template-engines]] ==== Template Engines As well as REST web services, you can also use Spring MVC to serve dynamic HTML content. -Spring MVC supports a variety of templating technologies, including Thymeleaf, -FreeMarker, and JSPs. Also, many other templating engines include their own Spring MVC -integrations. +Spring MVC supports a variety of templating technologies, including Thymeleaf, FreeMarker, and JSPs. +Also, many other templating engines include their own Spring MVC integrations. Spring Boot includes auto-configuration support for the following templating engines: @@ -2448,44 +2086,31 @@ Spring Boot includes auto-configuration support for the following templating eng * https://www.thymeleaf.org[Thymeleaf] * https://mustache.github.io/[Mustache] -TIP: If possible, JSPs should be avoided. There are several -<> when using them with embedded -servlet containers. +TIP: If possible, JSPs should be avoided. +There are several <> when using them with embedded servlet containers. -When you use one of these templating engines with the default configuration, your -templates are picked up automatically from `src/main/resources/templates`. +When you use one of these templating engines with the default configuration, your templates are picked up automatically from `src/main/resources/templates`. -TIP: Depending on how you run your application, IntelliJ IDEA orders the classpath -differently. Running your application in the IDE from its main method results in a -different ordering than when you run your application by using Maven or Gradle or from -its packaged jar. This can cause Spring Boot to fail to find the templates on the -classpath. If you have this problem, you can reorder the classpath in the IDE to place -the module's classes and resources first. Alternatively, you can configure the template -prefix to search every `templates` directory on the classpath, as follows: -`classpath*:/templates/`. +TIP: Depending on how you run your application, IntelliJ IDEA orders the classpath differently. +Running your application in the IDE from its main method results in a different ordering than when you run your application by using Maven or Gradle or from its packaged jar. +This can cause Spring Boot to fail to find the templates on the classpath. +If you have this problem, you can reorder the classpath in the IDE to place the module's classes and resources first. +Alternatively, you can configure the template prefix to search every `templates` directory on the classpath, as follows: `classpath*:/templates/`. [[boot-features-error-handling]] ==== Error Handling -By default, Spring Boot provides an `/error` mapping that handles all errors in a -sensible way, and it is registered as a "`global`" error page in the servlet container. -For machine clients, it produces a JSON response with details of the error, the HTTP -status, and the exception message. For browser clients, there is a "`whitelabel`" error -view that renders the same data in HTML format (to customize it, add a `View` that -resolves to `error`). To replace the default behavior completely, you can implement -`ErrorController` and register a bean definition of that type or add a bean of type -`ErrorAttributes` to use the existing mechanism but replace the contents. +By default, Spring Boot provides an `/error` mapping that handles all errors in a sensible way, and it is registered as a "`global`" error page in the servlet container. +For machine clients, it produces a JSON response with details of the error, the HTTP status, and the exception message. +For browser clients, there is a "`whitelabel`" error view that renders the same data in HTML format (to customize it, add a `View` that resolves to `error`). +To replace the default behavior completely, you can implement `ErrorController` and register a bean definition of that type or add a bean of type `ErrorAttributes` to use the existing mechanism but replace the contents. -TIP: The `BasicErrorController` can be used as a base class for a custom -`ErrorController`. This is particularly useful if you want to add a handler for a new -content type (the default is to handle `text/html` specifically and provide a fallback -for everything else). To do so, extend `BasicErrorController`, add a public method with a -`@RequestMapping` that has a `produces` attribute, and create a bean of your new type. +TIP: The `BasicErrorController` can be used as a base class for a custom `ErrorController`. +This is particularly useful if you want to add a handler for a new content type (the default is to handle `text/html` specifically and provide a fallback for everything else). +To do so, extend `BasicErrorController`, add a public method with a `@RequestMapping` that has a `produces` attribute, and create a bean of your new type. -You can also define a class annotated with `@ControllerAdvice` to customize the JSON -document to return for a particular controller and/or exception type, as shown in the -following example: +You can also define a class annotated with `@ControllerAdvice` to customize the JSON document to return for a particular controller and/or exception type, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2510,21 +2135,17 @@ following example: } ---- -In the preceding example, if `YourException` is thrown by a controller defined in the -same package as `AcmeController`, a JSON representation of the `CustomErrorType` POJO is -used instead of the `ErrorAttributes` representation. +In the preceding example, if `YourException` is thrown by a controller defined in the same package as `AcmeController`, a JSON representation of the `CustomErrorType` POJO is used instead of the `ErrorAttributes` representation. [[boot-features-error-handling-custom-error-pages]] ===== Custom Error Pages -If you want to display a custom HTML error page for a given status code, you can add a -file to an `/error` folder. Error pages can either be static HTML (that is, added under -any of the static resource folders) or be built by using templates. The name of the file -should be the exact status code or a series mask. +If you want to display a custom HTML error page for a given status code, you can add a file to an `/error` folder. +Error pages can either be static HTML (that is, added under any of the static resource folders) or be built by using templates. +The name of the file should be the exact status code or a series mask. -For example, to map `404` to a static HTML file, your folder structure would be as -follows: +For example, to map `404` to a static HTML file, your folder structure would be as follows: [source,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2539,8 +2160,7 @@ follows: +- ---- -To map all `5xx` errors by using a FreeMarker template, your folder structure would be as -follows: +To map all `5xx` errors by using a FreeMarker template, your folder structure would be as follows: [source,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2555,8 +2175,7 @@ follows: +- ---- -For more complex mappings, you can also add beans that implement the `ErrorViewResolver` -interface, as shown in the following example: +For more complex mappings, you can also add beans that implement the `ErrorViewResolver` interface, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2573,20 +2192,15 @@ interface, as shown in the following example: ---- -You can also use regular Spring MVC features such as -{spring-reference}web.html#mvc-exceptionhandlers[`@ExceptionHandler` methods] and -{spring-reference}web.html#mvc-ann-controller-advice[`@ControllerAdvice`]. The -`ErrorController` then picks up any unhandled exceptions. +You can also use regular Spring MVC features such as {spring-reference}web.html#mvc-exceptionhandlers[`@ExceptionHandler` methods] and {spring-reference}web.html#mvc-ann-controller-advice[`@ControllerAdvice`]. +The `ErrorController` then picks up any unhandled exceptions. [[boot-features-error-handling-mapping-error-pages-without-mvc]] ===== Mapping Error Pages outside of Spring MVC -For applications that do not use Spring MVC, you can use the `ErrorPageRegistrar` -interface to directly register `ErrorPages`. This abstraction works directly with the -underlying embedded servlet container and works even if you do not have a Spring MVC -`DispatcherServlet`. - +For applications that do not use Spring MVC, you can use the `ErrorPageRegistrar` interface to directly register `ErrorPages`. +This abstraction works directly with the underlying embedded servlet container and works even if you do not have a Spring MVC `DispatcherServlet`. [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2607,10 +2221,7 @@ underlying embedded servlet container and works even if you do not have a Spring } ---- -NOTE: If you register an `ErrorPage` with a path that ends up being handled by a `Filter` -(as is common with some non-Spring web frameworks, like Jersey and Wicket), then the -`Filter` has to be explicitly registered as an `ERROR` dispatcher, as shown in the -following example: +NOTE: If you register an `ErrorPage` with a path that ends up being handled by a `Filter` (as is common with some non-Spring web frameworks, like Jersey and Wicket), then the `Filter` has to be explicitly registered as an `ERROR` dispatcher, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2624,55 +2235,36 @@ following example: } ---- -Note that the default `FilterRegistrationBean` does not include the `ERROR` dispatcher -type. +Note that the default `FilterRegistrationBean` does not include the `ERROR` dispatcher type. [[boot-features-error-handling-websphere]] -CAUTION:When deployed to a servlet container, Spring Boot uses its error page filter to -forward a request with an error status to the appropriate error page. The request can only -be forwarded to the correct error page if the response has not already been committed. By -default, WebSphere Application Server 8.0 and later commits the response upon successful -completion of a servlet's service method. You should disable this behavior by setting -`com.ibm.ws.webcontainer.invokeFlushAfterService` to `false`. +CAUTION:When deployed to a servlet container, Spring Boot uses its error page filter to forward a request with an error status to the appropriate error page. +The request can only be forwarded to the correct error page if the response has not already been committed. +By default, WebSphere Application Server 8.0 and later commits the response upon successful completion of a servlet's service method. +You should disable this behavior by setting `com.ibm.ws.webcontainer.invokeFlushAfterService` to `false`. [[boot-features-spring-hateoas]] ==== Spring HATEOAS -If you develop a RESTful API that makes use of hypermedia, Spring Boot provides -auto-configuration for Spring HATEOAS that works well with most applications. The -auto-configuration replaces the need to use `@EnableHypermediaSupport` and registers a -number of beans to ease building hypermedia-based applications, including a -`LinkDiscoverers` (for client side support) and an `ObjectMapper` configured to correctly -marshal responses into the desired representation. The `ObjectMapper` is customized by -setting the various `spring.jackson.*` properties or, if one exists, by a -`Jackson2ObjectMapperBuilder` bean. +If you develop a RESTful API that makes use of hypermedia, Spring Boot provides auto-configuration for Spring HATEOAS that works well with most applications. +The auto-configuration replaces the need to use `@EnableHypermediaSupport` and registers a number of beans to ease building hypermedia-based applications, including a `LinkDiscoverers` (for client side support) and an `ObjectMapper` configured to correctly marshal responses into the desired representation. +The `ObjectMapper` is customized by setting the various `spring.jackson.*` properties or, if one exists, by a `Jackson2ObjectMapperBuilder` bean. -You can take control of Spring HATEOAS's configuration by using -`@EnableHypermediaSupport`. Note that doing so disables the `ObjectMapper` customization -described earlier. +You can take control of Spring HATEOAS's configuration by using `@EnableHypermediaSupport`. +Note that doing so disables the `ObjectMapper` customization described earlier. [[boot-features-cors]] ==== CORS Support - -https://en.wikipedia.org/wiki/Cross-origin_resource_sharing[Cross-origin resource sharing] -(CORS) is a https://www.w3.org/TR/cors/[W3C specification] implemented by -https://caniuse.com/#feat=cors[most browsers] that lets you specify in a flexible -way what kind of cross-domain requests are authorized, instead of using some less secure -and less powerful approaches such as IFRAME or JSONP. +https://en.wikipedia.org/wiki/Cross-origin_resource_sharing[Cross-origin resource sharing] (CORS) is a https://www.w3.org/TR/cors/[W3C specification] implemented by https://caniuse.com/#feat=cors[most browsers] that lets you specify in a flexible way what kind of cross-domain requests are authorized., instead of using some less secure and less powerful approaches such as IFRAME or JSONP. As of version 4.2, Spring MVC {spring-reference}web.html#cors[supports CORS]. -Using {spring-reference}web.html#controller-method-cors-configuration[controller method -CORS configuration] with -{spring-javadoc}/web/bind/annotation/CrossOrigin.{dc-ext}[`@CrossOrigin`] -annotations in your Spring Boot application does not require any specific configuration. -{spring-reference}web.html#global-cors-configuration[Global CORS configuration] can be -defined by registering a `WebMvcConfigurer` bean with a customized -`addCorsMappings(CorsRegistry)` method, as shown in the following example: +Using {spring-reference}web.html#controller-method-cors-configuration[controller method CORS configuration] with {spring-javadoc}/web/bind/annotation/CrossOrigin.{dc-ext}[`@CrossOrigin`] annotations in your Spring Boot application does not require any specific configuration. +{spring-reference}web.html#global-cors-configuration[Global CORS configuration] can be defined by registering a `WebMvcConfigurer` bean with a customized `addCorsMappings(CorsRegistry)` method, as shown in the following example: [source,java,indent=0] ---- @@ -2695,15 +2287,11 @@ defined by registering a `WebMvcConfigurer` bean with a customized [[boot-features-webflux]] === The "`Spring WebFlux Framework`" - Spring WebFlux is the new reactive web framework introduced in Spring Framework 5.0. -Unlike Spring MVC, it does not require the Servlet API, is fully asynchronous and -non-blocking, and implements the https://www.reactive-streams.org/[Reactive Streams] -specification through https://projectreactor.io/[the Reactor project]. +Unlike Spring MVC, it does not require the Servlet API, is fully asynchronous and non-blocking, and implements the https://www.reactive-streams.org/[Reactive Streams] specification through https://projectreactor.io/[the Reactor project]. -Spring WebFlux comes in two flavors: functional and annotation-based. The -annotation-based one is quite close to the Spring MVC model, as shown in the -following example: +Spring WebFlux comes in two flavors: functional and annotation-based. +The annotation-based one is quite close to the Spring MVC model, as shown in the following example: [source,java,indent=0] ---- @@ -2729,8 +2317,7 @@ following example: } ---- -"`WebFlux.fn`", the functional variant, separates the routing configuration from the -actual handling of the requests, as shown in the following example: +"`WebFlux.fn`", the functional variant, separates the routing configuration from the actual handling of the requests, as shown in the following example: [source,java,indent=0] ---- @@ -2763,55 +2350,43 @@ actual handling of the requests, as shown in the following example: } ---- -WebFlux is part of the Spring Framework and detailed information is available in its -{spring-reference}web-reactive.html#webflux-fn[reference documentation]. +WebFlux is part of the Spring Framework and detailed information is available in its {spring-reference}web-reactive.html#webflux-fn[reference documentation]. -TIP: You can define as many `RouterFunction` beans as you like to modularize the -definition of the router. Beans can be ordered if you need to apply a precedence. +TIP: You can define as many `RouterFunction` beans as you like to modularize the definition of the router. +Beans can be ordered if you need to apply a precedence. To get started, add the `spring-boot-starter-webflux` module to your application. -NOTE: Adding both `spring-boot-starter-web` and `spring-boot-starter-webflux` modules in -your application results in Spring Boot auto-configuring Spring MVC, not WebFlux. This -behavior has been chosen because many Spring developers add `spring-boot-starter-webflux` -to their Spring MVC application to use the reactive `WebClient`. You can still enforce -your choice by setting the chosen application type to -`SpringApplication.setWebApplicationType(WebApplicationType.REACTIVE)`. +NOTE: Adding both `spring-boot-starter-web` and `spring-boot-starter-webflux` modules in your application results in Spring Boot auto-configuring Spring MVC, not WebFlux. +This behavior has been chosen because many Spring developers add `spring-boot-starter-webflux` to their Spring MVC application to use the reactive `WebClient`. +You can still enforce your choice by setting the chosen application type to `SpringApplication.setWebApplicationType(WebApplicationType.REACTIVE)`. [[boot-features-webflux-auto-configuration]] ==== Spring WebFlux Auto-configuration -Spring Boot provides auto-configuration for Spring WebFlux that works well with most -applications. +Spring Boot provides auto-configuration for Spring WebFlux that works well with most applications. The auto-configuration adds the following features on top of Spring's defaults: -* Configuring codecs for `HttpMessageReader` and `HttpMessageWriter` instances (described -<>). -* Support for serving static resources, including support for WebJars (described -<>). +* Configuring codecs for `HttpMessageReader` and `HttpMessageWriter` instances (described <>). +* Support for serving static resources, including support for WebJars (described <>). -If you want to keep Spring Boot WebFlux features and you want to add additional -{spring-reference}web.html#web-reactive[WebFlux configuration], you can add your own -`@Configuration` class of type `WebFluxConfigurer` but *without* `@EnableWebFlux`. +If you want to keep Spring Boot WebFlux features and you want to add additional {spring-reference}web.html#web-reactive[WebFlux configuration], you can add your own `@Configuration` class of type `WebFluxConfigurer` but *without* `@EnableWebFlux`. -If you want to take complete control of Spring WebFlux, you can add your own -`@Configuration` annotated with `@EnableWebFlux`. +If you want to take complete control of Spring WebFlux, you can add your own `@Configuration` annotated with `@EnableWebFlux`. [[boot-features-webflux-httpcodecs]] ==== HTTP Codecs with HttpMessageReaders and HttpMessageWriters -Spring WebFlux uses the `HttpMessageReader` and `HttpMessageWriter` interfaces to convert -HTTP requests and responses. They are configured with `CodecConfigurer` to have sensible -defaults by looking at the libraries available in your classpath. +Spring WebFlux uses the `HttpMessageReader` and `HttpMessageWriter` interfaces to convert HTTP requests and responses. +They are configured with `CodecConfigurer` to have sensible defaults by looking at the libraries available in your classpath. -Spring Boot applies further customization by using `CodecCustomizer` instances. For -example, `spring.jackson.*` configuration keys are applied to the Jackson codec. +Spring Boot applies further customization by using `CodecCustomizer` instances. +For example, `spring.jackson.*` configuration keys are applied to the Jackson codec. -If you need to add or customize codecs, you can create a custom `CodecCustomizer` -component, as shown in the following example: +If you need to add or customize codecs, you can create a custom `CodecCustomizer` component, as shown in the following example: [source,java,indent=0] ---- @@ -2830,47 +2405,38 @@ component, as shown in the following example: } ---- -You can also leverage <>. +You can also leverage <>. [[boot-features-webflux-static-content]] ==== Static Content -By default, Spring Boot serves static content from a directory called `/static` (or -`/public` or `/resources` or `/META-INF/resources`) in the classpath. It uses the -`ResourceWebHandler` from Spring WebFlux so that you can modify that behavior by adding -your own `WebFluxConfigurer` and overriding the `addResourceHandlers` method. +By default, Spring Boot serves static content from a directory called `/static` (or `/public` or `/resources` or `/META-INF/resources`) in the classpath. +It uses the `ResourceWebHandler` from Spring WebFlux so that you can modify that behavior by adding your own `WebFluxConfigurer` and overriding the `addResourceHandlers` method. -By default, resources are mapped on `+/**+`, but you can tune that by setting the -`spring.webflux.static-path-pattern` property. For instance, relocating all resources to -`/resources/**` can be achieved as follows: +By default, resources are mapped on `+/**+`, but you can tune that by setting the `spring.webflux.static-path-pattern` property. +For instance, relocating all resources to `/resources/**` can be achieved as follows: [source,properties,indent=0,subs="verbatim,quotes,attributes"] ---- spring.webflux.static-path-pattern=/resources/** ---- -You can also customize the static resource locations by using -`spring.resources.static-locations`. Doing so replaces the default values with a list of -directory locations. If you do so, the default welcome page detection switches to your -custom locations. So, if there is an `index.html` in any of your locations on startup, it -is the home page of the application. +You can also customize the static resource locations by using `spring.resources.static-locations`. +Doing so replaces the default values with a list of directory locations. If you do so, the default welcome page detection switches to your custom locations. +So, if there is an `index.html` in any of your locations on startup, it is the home page of the application. -In addition to the "`standard`" static resource locations listed earlier, a special case -is made for https://www.webjars.org/[Webjars content]. Any resources with a path in -`+/webjars/**+` are served from jar files if they are packaged in the Webjars format. +In addition to the "`standard`" static resource locations listed earlier, a special case is made for https://www.webjars.org/[Webjars content]. +Any resources with a path in `+/webjars/**+` are served from jar files if they are packaged in the Webjars format. -TIP: Spring WebFlux applications do not strictly depend on the Servlet API, so they -cannot be deployed as war files and do not use the `src/main/webapp` directory. +TIP: Spring WebFlux applications do not strictly depend on the Servlet API, so they cannot be deployed as war files and do not use the `src/main/webapp` directory. [[boot-features-webflux-template-engines]] ==== Template Engines -As well as REST web services, you can also use Spring WebFlux to serve dynamic HTML -content. Spring WebFlux supports a variety of templating technologies, including -Thymeleaf, FreeMarker, and Mustache. +As well as REST web services, you can also use Spring WebFlux to serve dynamic HTML content. +Spring WebFlux supports a variety of templating technologies, including Thymeleaf, FreeMarker, and Mustache. Spring Boot includes auto-configuration support for the following templating engines: @@ -2878,30 +2444,23 @@ Spring Boot includes auto-configuration support for the following templating eng * https://www.thymeleaf.org[Thymeleaf] * https://mustache.github.io/[Mustache] -When you use one of these templating engines with the default configuration, your -templates are picked up automatically from `src/main/resources/templates`. +When you use one of these templating engines with the default configuration, your templates are picked up automatically from `src/main/resources/templates`. [[boot-features-webflux-error-handling]] ==== Error Handling - Spring Boot provides a `WebExceptionHandler` that handles all errors in a sensible way. -Its position in the processing order is immediately before the handlers provided by -WebFlux, which are considered last. For machine clients, it produces a JSON response -with details of the error, the HTTP status, and the exception message. For browser -clients, there is a "`whitelabel`" error handler that renders the same data in HTML -format. You can also provide your own HTML templates to display errors (see the -<>). +Its position in the processing order is immediately before the handlers provided by WebFlux, which are considered last. +For machine clients, it produces a JSON response with details of the error, the HTTP status, and the exception message. +For browser clients, there is a "`whitelabel`" error handler that renders the same data in HTML format. +You can also provide your own HTML templates to display errors (see the <>). -The first step to customizing this feature often involves using the existing mechanism -but replacing or augmenting the error contents. For that, you can add a bean of type -`ErrorAttributes`. +The first step to customizing this feature often involves using the existing mechanism but replacing or augmenting the error contents. +For that, you can add a bean of type`ErrorAttributes`. -To change the error handling behavior, you can implement `ErrorWebExceptionHandler` and -register a bean definition of that type. Because a `WebExceptionHandler` is quite -low-level, Spring Boot also provides a convenient `AbstractErrorWebExceptionHandler` to -let you handle errors in a WebFlux functional way, as shown in the following example: +To change the error handling behavior, you can implement `ErrorWebExceptionHandler` and register a bean definition of that type. +Because a `WebExceptionHandler` is quite low-level, Spring Boot also provides a convenient `AbstractErrorWebExceptionHandler` to let you handle errors in a WebFlux functional way, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2920,21 +2479,17 @@ let you handle errors in a WebFlux functional way, as shown in the following exa } ---- -For a more complete picture, you can also subclass `DefaultErrorWebExceptionHandler` -directly and override specific methods. +For a more complete picture, you can also subclass `DefaultErrorWebExceptionHandler` directly and override specific methods. [[boot-features-webflux-error-handling-custom-error-pages]] ===== Custom Error Pages +If you want to display a custom HTML error page for a given status code, you can add a file to an `/error` folder. +Error pages can either be static HTML (that is, added under any of the static resource folders) or built with templates. +The name of the file should be the exact status code or a series mask. -If you want to display a custom HTML error page for a given status code, you can add a -file to an `/error` folder. Error pages can either be static HTML (that is, added under -any of the static resource folders) or built with templates. The name of the file should -be the exact status code or a series mask. - -For example, to map `404` to a static HTML file, your folder structure would be as -follows: +For example, to map `404` to a static HTML file, your folder structure would be as follows: [source,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2949,8 +2504,7 @@ follows: +- ---- -To map all `5xx` errors by using a Mustache template, your folder structure would be as -follows: +To map all `5xx` errors by using a Mustache template, your folder structure would be as follows: [source,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -2969,42 +2523,36 @@ follows: [[boot-features-webflux-web-filters]] ==== Web Filters -Spring WebFlux provides a `WebFilter` interface that can be implemented to filter HTTP -request-response exchanges. `WebFilter` beans found in the application context will -be automatically used to filter each exchange. +Spring WebFlux provides a `WebFilter` interface that can be implemented to filter HTTP request-response exchanges. +`WebFilter` beans found in the application context will be automatically used to filter each exchange. -Where the order of the filters is important they can implement `Ordered` or be annotated -with `@Order`. Spring Boot auto-configuration may configure web filters for you. When it -does so, the orders shown in the following table will be used: +Where the order of the filters is important they can implement `Ordered` or be annotated with `@Order`. +Spring Boot auto-configuration may configure web filters for you. +When it does so, the orders shown in the following table will be used: |=== | Web Filter | Order -|`MetricsWebFilter` -|`Ordered.HIGHEST_PRECEDENCE + 1` +| `MetricsWebFilter` +| `Ordered.HIGHEST_PRECEDENCE + 1` -|`WebFilterChainProxy` (Spring Security) -|`-100` - -|`HttpTraceWebFilter` -|`Ordered.LOWEST_PRECEDENCE - 10` +| `WebFilterChainProxy` (Spring Security) +| `-100` +| `HttpTraceWebFilter` +| `Ordered.LOWEST_PRECEDENCE - 10` |=== [[boot-features-jersey]] === JAX-RS and Jersey -If you prefer the JAX-RS programming model for REST endpoints, you can use one of the -available implementations instead of Spring MVC. https://jersey.github.io/[Jersey] and -https://cxf.apache.org/[Apache CXF] work quite well out of the box. CXF requires you to -register its `Servlet` or `Filter` as a `@Bean` in your application context. Jersey has -some native Spring support, so we also provide auto-configuration support for it in -Spring Boot, together with a starter. +If you prefer the JAX-RS programming model for REST endpoints, you can use one of the available implementations instead of Spring MVC. +https://jersey.github.io/[Jersey] and https://cxf.apache.org/[Apache CXF] work quite well out of the box. +CXF requires you to register its `Servlet` or `Filter` as a `@Bean` in your application context. +Jersey has some native Spring support, so we also provide auto-configuration support for it in Spring Boot, together with a starter. -To get started with Jersey, include the `spring-boot-starter-jersey` as a dependency -and then you need one `@Bean` of type `ResourceConfig` in which you register all the -endpoints, as shown in the following example: +To get started with Jersey, include the `spring-boot-starter-jersey` as a dependency and then you need one `@Bean` of type `ResourceConfig` in which you register all the endpoints, as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3018,18 +2566,13 @@ endpoints, as shown in the following example: } ---- -WARNING: Jersey's support for scanning executable archives is rather limited. For example, -it cannot scan for endpoints in a package found in a <> or in `WEB-INF/classes` when running an executable war file. -To avoid this limitation, the `packages` method should not be used, and endpoints should -be registered individually by using the `register` method, as shown in the preceding -example. +WARNING: Jersey's support for scanning executable archives is rather limited. +For example, it cannot scan for endpoints in a package found in a <> or in `WEB-INF/classes` when running an executable war file. +To avoid this limitation, the `packages` method should not be used, and endpoints should be registered individually by using the `register` method, as shown in the preceding example. -For more advanced customizations, you can also register an arbitrary number of beans that -implement `ResourceConfigCustomizer`. +For more advanced customizations, you can also register an arbitrary number of beans that implement `ResourceConfigCustomizer`. -All the registered endpoints should be `@Components` with HTTP resource annotations -(`@GET` and others), as shown in the following example: +All the registered endpoints should be `@Components` with HTTP resource annotations (`@GET` and others), as shown in the following example: [source,java,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -3045,167 +2588,126 @@ All the registered endpoints should be `@Components` with HTTP resource annotati } ---- -Since the `Endpoint` is a Spring `@Component`, its lifecycle is managed by Spring and you -can use the `@Autowired` annotation to inject dependencies and use the `@Value` -annotation to inject external configuration. By default, the Jersey servlet is registered -and mapped to `/*`. You can change the mapping by adding `@ApplicationPath` to your -`ResourceConfig`. +Since the `Endpoint` is a Spring `@Component`, its lifecycle is managed by Spring and you can use the `@Autowired` annotation to inject dependencies and use the `@Value` annotation to inject external configuration. +By default, the Jersey servlet is registered and mapped to `/*`. You can change the mapping by adding `@ApplicationPath` to your `ResourceConfig`. -By default, Jersey is set up as a Servlet in a `@Bean` of type `ServletRegistrationBean` -named `jerseyServletRegistration`. By default, the servlet is initialized lazily, but you -can customize that behavior by setting `spring.jersey.servlet.load-on-startup`. You can -disable or override that bean by creating one of your own with the same name. You can -also use a filter instead of a servlet by setting `spring.jersey.type=filter` (in which -case, the `@Bean` to replace or override is `jerseyFilterRegistration`). The filter has -an `@Order`, which you can set with `spring.jersey.filter.order`. Both the servlet and -the filter registrations can be given init parameters by using `spring.jersey.init.*` to -specify a map of properties. +By default, Jersey is set up as a Servlet in a `@Bean` of type `ServletRegistrationBean` named `jerseyServletRegistration`. +By default, the servlet is initialized lazily, but you can customize that behavior by setting `spring.jersey.servlet.load-on-startup`. +You can disable or override that bean by creating one of your own with the same name. +You can also use a filter instead of a servlet by setting `spring.jersey.type=filter` (in which case, the `@Bean` to replace or override is `jerseyFilterRegistration`). +The filter has an `@Order`, which you can set with `spring.jersey.filter.order`. +Both the servlet and the filter registrations can be given init parameters by using `spring.jersey.init.*` to specify a map of properties. -There is a {github-code}/spring-boot-samples/spring-boot-sample-jersey[Jersey sample] so -that you can see how to set things up. +There is a {github-code}/spring-boot-samples/spring-boot-sample-jersey[Jersey sample] so that you can see how to set things up. [[boot-features-embedded-container]] === Embedded Servlet Container Support -Spring Boot includes support for embedded https://tomcat.apache.org/[Tomcat], -https://www.eclipse.org/jetty/[Jetty], and -https://github.com/undertow-io/undertow[Undertow] servers. Most developers use the -appropriate "`Starter`" to obtain a fully configured instance. By default, the embedded -server listens for HTTP requests on port `8080`. +Spring Boot includes support for embedded https://tomcat.apache.org/[Tomcat], https://www.eclipse.org/jetty/[Jetty], and https://github.com/undertow-io/undertow[Undertow] servers. +Most developers use the appropriate "`Starter`" to obtain a fully configured instance. +By default, the embedded server listens for HTTP requests on port `8080`. [[boot-features-embedded-container-servlets-filters-listeners]] ==== Servlets, Filters, and listeners -When using an embedded servlet container, you can register servlets, filters, and all the -listeners (such as `HttpSessionListener`) from the Servlet spec, either by using Spring -beans or by scanning for Servlet components. +When using an embedded servlet container, you can register servlets, filters, and all the listeners (such as `HttpSessionListener`) from the Servlet spec, either by using Spring beans or by scanning for Servlet components. + [[boot-features-embedded-container-servlets-filters-listeners-beans]] ===== Registering Servlets, Filters, and Listeners as Spring Beans -Any `Servlet`, `Filter`, or servlet `*Listener` instance that is a Spring bean is -registered with the embedded container. This can be particularly convenient if you want -to refer to a value from your `application.properties` during configuration. +Any `Servlet`, `Filter`, or servlet `*Listener` instance that is a Spring bean is registered with the embedded container. +This can be particularly convenient if you want to refer to a value from your `application.properties` during configuration. -By default, if the context contains only a single Servlet, it is mapped to `/`. In the -case of multiple servlet beans, the bean name is used as a path prefix. Filters map to -`+/*+`. +By default, if the context contains only a single Servlet, it is mapped to `/`. +In the case of multiple servlet beans, the bean name is used as a path prefix. +Filters map to `+/*+`. -If convention-based mapping is not flexible enough, you can use the -`ServletRegistrationBean`, `FilterRegistrationBean`, and -`ServletListenerRegistrationBean` classes for complete control. +If convention-based mapping is not flexible enough, you can use the `ServletRegistrationBean`, `FilterRegistrationBean`, and `ServletListenerRegistrationBean` classes for complete control. -Spring Boot ships with many auto-configurations that may define Filter beans. Here are a -few examples of Filters and their respective order (lower order value means higher -precedence): +Spring Boot ships with many auto-configurations that may define Filter beans. +Here are a few examples of Filters and their respective order (lower order value means higher precedence): |=== | Servlet Filter | Order -|`OrderedCharacterEncodingFilter` -|`Ordered.HIGHEST_PRECEDENCE` +| `OrderedCharacterEncodingFilter` +| `Ordered.HIGHEST_PRECEDENCE` -|`WebMvcMetricsFilter` -|`Ordered.HIGHEST_PRECEDENCE + 1` +| `WebMvcMetricsFilter` +| `Ordered.HIGHEST_PRECEDENCE + 1` -|`ErrorPageFilter` -|`Ordered.HIGHEST_PRECEDENCE + 1` +| `ErrorPageFilter` +| `Ordered.HIGHEST_PRECEDENCE + 1` -|`HttpTraceFilter` -|`Ordered.LOWEST_PRECEDENCE - 10` +| `HttpTraceFilter` +| `Ordered.LOWEST_PRECEDENCE - 10` |=== It is usually safe to leave Filter beans unordered. -If a specific order is required, you should avoid configuring a Filter that reads the -request body at `Ordered.HIGHEST_PRECEDENCE`, since it might go against the character -encoding configuration of your application. If a Servlet filter wraps the request, it -should be configured with an order that is less than or equal to -`OrderedFilter.REQUEST_WRAPPER_FILTER_MAX_ORDER`. +If a specific order is required, you should avoid configuring a Filter that reads the request body at `Ordered.HIGHEST_PRECEDENCE`, since it might go against the character encoding configuration of your application. +If a Servlet filter wraps the request, it should be configured with an order that is less than or equal to `OrderedFilter.REQUEST_WRAPPER_FILTER_MAX_ORDER`. [[boot-features-embedded-container-context-initializer]] ==== Servlet Context Initialization -Embedded servlet containers do not directly execute the Servlet 3.0+ -`javax.servlet.ServletContainerInitializer` interface or Spring's -`org.springframework.web.WebApplicationInitializer` interface. This is an intentional -design decision intended to reduce the risk that third party libraries designed to run -inside a war may break Spring Boot applications. +Embedded servlet containers do not directly execute the Servlet 3.0+ `javax.servlet.ServletContainerInitializer` interface or Spring's `org.springframework.web.WebApplicationInitializer` interface. +This is an intentional design decision intended to reduce the risk that third party libraries designed to run inside a war may break Spring Boot applications. -If you need to perform servlet context initialization in a Spring Boot application, you -should register a bean that implements the -`org.springframework.boot.web.servlet.ServletContextInitializer` interface. The -single `onStartup` method provides access to the `ServletContext` and, if necessary, can -easily be used as an adapter to an existing `WebApplicationInitializer`. +If you need to perform servlet context initialization in a Spring Boot application, you should register a bean that implements the `org.springframework.boot.web.servlet.ServletContextInitializer` interface. +The single `onStartup` method provides access to the `ServletContext` and, if necessary, can easily be used as an adapter to an existing `WebApplicationInitializer`. [[boot-features-embedded-container-servlets-filters-listeners-scanning]] ===== Scanning for Servlets, Filters, and listeners -When using an embedded container, automatic registration of classes annotated with -`@WebServlet`, `@WebFilter`, and `@WebListener` can be enabled by using -`@ServletComponentScan`. +When using an embedded container, automatic registration of classes annotated with `@WebServlet`, `@WebFilter`, and `@WebListener` can be enabled by using `@ServletComponentScan`. -TIP: `@ServletComponentScan` has no effect in a standalone container, where the -container's built-in discovery mechanisms are used instead. +TIP: `@ServletComponentScan` has no effect in a standalone container, where the container's built-in discovery mechanisms are used instead. [[boot-features-embedded-container-application-context]] ==== The ServletWebServerApplicationContext -Under the hood, Spring Boot uses a different type of `ApplicationContext` for embedded -servlet container support. The `ServletWebServerApplicationContext` is a special type of -`WebApplicationContext` that bootstraps itself by searching for a single -`ServletWebServerFactory` bean. Usually a `TomcatServletWebServerFactory`, -`JettyServletWebServerFactory`, or `UndertowServletWebServerFactory` -has been auto-configured. +Under the hood, Spring Boot uses a different type of `ApplicationContext` for embedded servlet container support. +The `ServletWebServerApplicationContext` is a special type of `WebApplicationContext` that bootstraps itself by searching for a single `ServletWebServerFactory` bean. +Usually a `TomcatServletWebServerFactory`, `JettyServletWebServerFactory`, or `UndertowServletWebServerFactory` has been auto-configured. -NOTE: You usually do not need to be aware of these implementation classes. Most -applications are auto-configured, and the appropriate `ApplicationContext` and -`ServletWebServerFactory` are created on your behalf. +NOTE: You usually do not need to be aware of these implementation classes. +Most applications are auto-configured, and the appropriate `ApplicationContext` and `ServletWebServerFactory` are created on your behalf. [[boot-features-customizing-embedded-containers]] ==== Customizing Embedded Servlet Containers -Common servlet container settings can be configured by using Spring `Environment` -properties. Usually, you would define the properties in your `application.properties` -file. +Common servlet container settings can be configured by using Spring `Environment` properties. +Usually, you would define the properties in your `application.properties` file. Common server settings include: -* Network settings: Listen port for incoming HTTP requests (`server.port`), interface -address to bind to `server.address`, and so on. -* Session settings: Whether the session is persistent (`server.servlet.session.persistent`), -session timeout (`server.servlet.session.timeout`), location of session data -(`server.servlet.session.store-dir`), and session-cookie configuration -(`server.servlet.session.cookie.*`). +* Network settings: Listen port for incoming HTTP requests (`server.port`), interface address to bind to `server.address`, and so on. +* Session settings: Whether the session is persistent (`server.servlet.session.persistent`), session timeout (`server.servlet.session.timeout`), location of session data (`server.servlet.session.store-dir`), and session-cookie configuration (`server.servlet.session.cookie.*`). * Error management: Location of the error page (`server.error.path`) and so on. * <> * <> -Spring Boot tries as much as possible to expose common settings, but this is not always -possible. For those cases, dedicated namespaces offer server-specific customizations (see -`server.tomcat` and `server.undertow`). For instance, -<> can be configured with specific -features of the embedded servlet container. +Spring Boot tries as much as possible to expose common settings, but this is not always possible. +For those cases, dedicated namespaces offer server-specific customizations (see `server.tomcat` and `server.undertow`). +For instance, <> can be configured with specific features of the embedded servlet container. -TIP: See the -{sc-spring-boot-autoconfigure}/web/ServerProperties.{sc-ext}[`ServerProperties`] class -for a complete list. +TIP: See the {sc-spring-boot-autoconfigure}/web/ServerProperties.{sc-ext}[`ServerProperties`] class for a complete list. [[boot-features-programmatic-embedded-container-customization]] ===== Programmatic Customization -If you need to programmatically configure your embedded servlet container, you can -register a Spring bean that implements the `WebServerFactoryCustomizer` interface. -`WebServerFactoryCustomizer` provides access to the -`ConfigurableServletWebServerFactory`, which includes numerous customization setter -methods. The following example shows programmatically setting the port: +If you need to programmatically configure your embedded servlet container, you can register a Spring bean that implements the `WebServerFactoryCustomizer` interface. +`WebServerFactoryCustomizer` provides access to the `ConfigurableServletWebServerFactory`, which includes numerous customization setter methods. +The following example shows programmatically setting the port: [source,java,indent=0] ---- @@ -3224,15 +2726,13 @@ methods. The following example shows programmatically setting the port: } ---- -NOTE: `TomcatServletWebServerFactory`, `JettyServletWebServerFactory` and `UndertowServletWebServerFactory` -are dedicated variants of `ConfigurableServletWebServerFactory` that have additional customization setter methods -for Tomcat, Jetty and Undertow respectively. +NOTE: `TomcatServletWebServerFactory`, `JettyServletWebServerFactory` and `UndertowServletWebServerFactory` are dedicated variants of `ConfigurableServletWebServerFactory` that have additional customization setter methods for Tomcat, Jetty and Undertow respectively. + + [[boot-features-customizing-configurableservletwebserverfactory-directly]] ===== Customizing ConfigurableServletWebServerFactory Directly -If the preceding customization techniques are too limited, you can register the -`TomcatServletWebServerFactory`, `JettyServletWebServerFactory`, or -`UndertowServletWebServerFactory` bean yourself. +If the preceding customization techniques are too limited, you can register the `TomcatServletWebServerFactory`, `JettyServletWebServerFactory`, or `UndertowServletWebServerFactory` bean yourself. [source,java,indent=0] ---- @@ -3246,146 +2746,110 @@ If the preceding customization techniques are too limited, you can register the } ---- -Setters are provided for many configuration options. Several protected method "`hooks`" -are also provided should you need to do something more exotic. See the -{dc-spring-boot}/web/servlet/server/ConfigurableServletWebServerFactory.{dc-ext}[source -code documentation] for details. +Setters are provided for many configuration options. +Several protected method "`hooks`" are also provided should you need to do something more exotic. +See the {dc-spring-boot}/web/servlet/server/ConfigurableServletWebServerFactory.{dc-ext}[source code documentation] for details. + [[boot-features-jsp-limitations]] ==== JSP Limitations -When running a Spring Boot application that uses an embedded servlet container (and is -packaged as an executable archive), there are some limitations in the JSP support. +When running a Spring Boot application that uses an embedded servlet container (and is packaged as an executable archive), there are some limitations in the JSP support. -* With Jetty and Tomcat, it should work if you use war packaging. An executable war will - work when launched with `java -jar`, and will also be deployable to any standard - container. JSPs are not supported when using an executable jar. +* With Jetty and Tomcat, it should work if you use war packaging. + An executable war will work when launched with `java -jar`, and will also be deployable to any standard container. + JSPs are not supported when using an executable jar. * Undertow does not support JSPs. -* Creating a custom `error.jsp` page does not override the default view for -<>. -<> should be used -instead. +* Creating a custom `error.jsp` page does not override the default view for <>. + <> should be used instead. + +There is a {github-code}/spring-boot-samples/spring-boot-sample-web-jsp[JSP sample] so that you can see how to set things up. + -There is a {github-code}/spring-boot-samples/spring-boot-sample-web-jsp[JSP sample] so -that you can see how to set things up. [[boot-features-reactive-server]] === Embedded Reactive Server Support +Spring Boot includes support for the following embedded reactive web servers: Reactor Netty, Tomcat, Jetty, and Undertow. +Most developers use the appropriate “Starter” to obtain a fully configured instance. +By default, the embedded server listens for HTTP requests on port 8080. + -Spring Boot includes support for the following embedded reactive web servers: -Reactor Netty, Tomcat, Jetty, and Undertow. Most developers use the appropriate “Starter” -to obtain a fully configured instance. By default, the embedded server listens for HTTP -requests on port 8080. [[boot-features-reactive-server-resources]] === Reactive Server Resources Configuration +When auto-configuring a Reactor Netty or Jetty server, Spring Boot will create specific beans that will provide HTTP resources to the server instance: `ReactorResourceFactory` or `JettyResourceFactory`. -When auto-configuring a Reactor Netty or Jetty server, Spring Boot will create specific -beans that will provide HTTP resources to the server instance: `ReactorResourceFactory` -or `JettyResourceFactory`. - -By default, those resources will be also shared with the Reactor Netty and Jetty clients -for optimal performances, given: +By default, those resources will be also shared with the Reactor Netty and Jetty clients for optimal performances, given: * the same technology is used for server and client -* the client instance is built using the `WebClient.Builder` bean auto-configured by -Spring Boot +* the client instance is built using the `WebClient.Builder` bean auto-configured by Spring Boot -Developers can override the resource configuration for Jetty and Reactor Netty by providing -a custom `ReactorResourceFactory` or `JettyResourceFactory` bean - this will be applied to -both clients and servers. +Developers can override the resource configuration for Jetty and Reactor Netty by providing a custom `ReactorResourceFactory` or `JettyResourceFactory` bean - this will be applied to both clients and servers. -You can learn more about the resource configuration on the client side in the -<>. +You can learn more about the resource configuration on the client side in the <>. [[boot-features-security]] == Security -If {spring-security}[Spring Security] is on the classpath, then web applications are -secured by default. Spring Boot relies on Spring Security’s content-negotiation strategy -to determine whether to use `httpBasic` or `formLogin`. To add method-level security to a -web application, you can also add `@EnableGlobalMethodSecurity` with your desired -settings. Additional information can be found in the -{spring-security-reference}#jc-method[Spring Security Reference Guide]. +If {spring-security}[Spring Security] is on the classpath, then web applications are secured by default. +Spring Boot relies on Spring Security’s content-negotiation strategy to determine whether to use `httpBasic` or `formLogin`. +To add method-level security to a web application, you can also add `@EnableGlobalMethodSecurity` with your desired settings. +Additional information can be found in the {spring-security-reference}#jc-method[Spring Security Reference Guide]. -The default `UserDetailsService` has a single user. The user name is `user`, and the -password is random and is printed at INFO level when the application starts, as shown in -the following example: +The default `UserDetailsService` has a single user. The user name is `user`, and the password is random and is printed at INFO level when the application starts, as shown in the following example: [indent=0] ---- Using generated security password: 78fa095d-3f4c-48b1-ad50-e24c31d5cf35 ---- -NOTE: If you fine-tune your logging configuration, ensure that the -`org.springframework.boot.autoconfigure.security` category is set to log `INFO`-level -messages. Otherwise, the default password is not printed. +NOTE: If you fine-tune your logging configuration, ensure that the `org.springframework.boot.autoconfigure.security` category is set to log `INFO`-level messages. +Otherwise, the default password is not printed. -You can change the username and password by providing a `spring.security.user.name` and -`spring.security.user.password`. +You can change the username and password by providing a `spring.security.user.name` and `spring.security.user.password`. The basic features you get by default in a web application are: -* A `UserDetailsService` (or `ReactiveUserDetailsService` in case of a WebFlux application) -bean with in-memory store and a single user with a generated password (see -{dc-spring-boot}/autoconfigure/security/SecurityProperties.User.html[`SecurityProperties.User`] -for the properties of the user). -* Form-based login or HTTP Basic security (depending on the `Accept` header in the request) for -the entire application (including actuator endpoints if actuator is on the classpath). +* A `UserDetailsService` (or `ReactiveUserDetailsService` in case of a WebFlux application) bean with in-memory store and a single user with a generated password (see {dc-spring-boot}/autoconfigure/security/SecurityProperties.User.html[`SecurityProperties.User`] for the properties of the user). +* Form-based login or HTTP Basic security (depending on the `Accept` header in the request) for the entire application (including actuator endpoints if actuator is on the classpath). * A `DefaultAuthenticationEventPublisher` for publishing authentication events. You can provide a different `AuthenticationEventPublisher` by adding a bean for it. + [[boot-features-security-mvc]] === MVC Security -The default security configuration is implemented in `SecurityAutoConfiguration` and -`UserDetailsServiceAutoConfiguration`. `SecurityAutoConfiguration` imports -`SpringBootWebSecurityConfiguration` for web security and -`UserDetailsServiceAutoConfiguration` configures authentication, which is also -relevant in non-web applications. To switch off the default web application security -configuration completely, you can add a bean of type `WebSecurityConfigurerAdapter` (doing -so does not disable the `UserDetailsService` configuration or Actuator's security). +The default security configuration is implemented in `SecurityAutoConfiguration` and `UserDetailsServiceAutoConfiguration`. +`SecurityAutoConfiguration` imports `SpringBootWebSecurityConfiguration` for web security and `UserDetailsServiceAutoConfiguration` configures authentication, which is also relevant in non-web applications. +To switch off the default web application security configuration completely, you can add a bean of type `WebSecurityConfigurerAdapter` (doing so does not disable the `UserDetailsService` configuration or Actuator's security). -To also switch off the `UserDetailsService` configuration, you can add a bean of type -`UserDetailsService`, `AuthenticationProvider`, or `AuthenticationManager`. -There are several secure applications in the {github-code}/spring-boot-samples/[Spring -Boot samples] to get you started with common use cases. +To also switch off the `UserDetailsService` configuration, you can add a bean of type `UserDetailsService`, `AuthenticationProvider`, or `AuthenticationManager`. +There are several secure applications in the {github-code}/spring-boot-samples/[Spring Boot samples] to get you started with common use cases. -Access rules can be overridden by adding a custom `WebSecurityConfigurerAdapter`. Spring -Boot provides convenience methods that can be used to override access rules for actuator -endpoints and static resources. `EndpointRequest` can be used to create a `RequestMatcher` -that is based on the `management.endpoints.web.base-path` property. -`PathRequest` can be used to create a `RequestMatcher` for resources in -commonly used locations. +Access rules can be overridden by adding a custom `WebSecurityConfigurerAdapter`. +Spring Boot provides convenience methods that can be used to override access rules for actuator endpoints and static resources. +`EndpointRequest` can be used to create a `RequestMatcher` that is based on the `management.endpoints.web.base-path` property. +`PathRequest` can be used to create a `RequestMatcher` for resources in commonly used locations. [[boot-features-security-webflux]] === WebFlux Security -Similar to Spring MVC applications, you can secure your WebFlux applications by adding -the `spring-boot-starter-security` dependency. The default security configuration is -implemented in `ReactiveSecurityAutoConfiguration` and -`UserDetailsServiceAutoConfiguration`. `ReactiveSecurityAutoConfiguration` imports -`WebFluxSecurityConfiguration` for web security and `UserDetailsServiceAutoConfiguration` -configures authentication, which is also relevant in non-web applications. To switch off the default web application security -configuration completely, you can add a bean of type `WebFilterChainProxy` (doing so does -not disable the `UserDetailsService` configuration or Actuator's security). +Similar to Spring MVC applications, you can secure your WebFlux applications by adding the `spring-boot-starter-security` dependency. +The default security configuration is implemented in `ReactiveSecurityAutoConfiguration` and `UserDetailsServiceAutoConfiguration`. `ReactiveSecurityAutoConfiguration` imports `WebFluxSecurityConfiguration` for web security and `UserDetailsServiceAutoConfiguration` configures authentication, which is also relevant in non-web applications. +To switch off the default web application security configuration completely, you can add a bean of type `WebFilterChainProxy` (doing so does not disable the `UserDetailsService` configuration or Actuator's security). -To also switch off the `UserDetailsService` configuration, you can add a bean of type -`ReactiveUserDetailsService` or `ReactiveAuthenticationManager`. +To also switch off the `UserDetailsService` configuration, you can add a bean of type `ReactiveUserDetailsService` or `ReactiveAuthenticationManager`. -Access rules can be configured by adding a custom `SecurityWebFilterChain`. Spring -Boot provides convenience methods that can be used to override access rules for actuator -endpoints and static resources. `EndpointRequest` can be used to create a -`ServerWebExchangeMatcher` that is based on the `management.endpoints.web.base-path` -property. +Access rules can be configured by adding a custom `SecurityWebFilterChain`. +Spring Boot provides convenience methods that can be used to override access rules for actuator endpoints and static resources. +`EndpointRequest` can be used to create a `ServerWebExchangeMatcher` that is based on the `management.endpoints.web.base-path` property. -`PathRequest` can be used to create a `ServerWebExchangeMatcher` for resources in -commonly used locations. +`PathRequest` can be used to create a `ServerWebExchangeMatcher` for resources in commonly used locations. For example, you can customize your security configuration by adding something like: @@ -3398,19 +2862,17 @@ include::{code-examples}/web/security/CustomWebFluxSecurityExample.java[tag=conf [[boot-features-security-oauth2]] === OAuth2 -https://oauth.net/2/[OAuth2] is a widely used authorization framework that is supported by -Spring. +https://oauth.net/2/[OAuth2] is a widely used authorization framework that is supported by Spring. [[boot-features-security-oauth2-client]] ==== Client -If you have `spring-security-oauth2-client` on your classpath, you can take advantage of -some auto-configuration to make it easy to set up an OAuth2/Open ID Connect clients. This configuration -makes use of the properties under `OAuth2ClientProperties`. The same properties are applicable to both servlet and reactive applications. +If you have `spring-security-oauth2-client` on your classpath, you can take advantage of some auto-configuration to make it easy to set up an OAuth2/Open ID Connect clients. +This configuration makes use of the properties under `OAuth2ClientProperties`. +The same properties are applicable to both servlet and reactive applications. -You can register multiple OAuth2 clients and providers under the -`spring.security.oauth2.client` prefix, as shown in the following example: +You can register multiple OAuth2 clients and providers under the `spring.security.oauth2.client` prefix, as shown in the following example: [source,properties,indent=0] ---- @@ -3440,26 +2902,20 @@ You can register multiple OAuth2 clients and providers under the spring.security.oauth2.client.provider.my-oauth-provider.user-name-attribute=name ---- -For OpenID Connect providers that support https://openid.net/specs/openid-connect-discovery-1_0.html[OpenID Connect discovery], -the configuration can be further simplified. The provider needs to be configured with an `issuer-uri` which is the -URI that the it asserts as its Issuer Identifier. For example, if the -`issuer-uri` provided is "https://example.com", then an `OpenID Provider Configuration Request` -will be made to "https://example.com/.well-known/openid-configuration". The result is expected -to be an `OpenID Provider Configuration Response`. The following example shows how an OpenID Connect -Provider can be configured with the `issuer-uri`: +For OpenID Connect providers that support https://openid.net/specs/openid-connect-discovery-1_0.html[OpenID Connect discovery], the configuration can be further simplified. +The provider needs to be configured with an `issuer-uri` which is the URI that the it asserts as its Issuer Identifier. +For example, if the `issuer-uri` provided is "https://example.com", then an `OpenID Provider Configuration Request` will be made to "https://example.com/.well-known/openid-configuration". +The result is expected to be an `OpenID Provider Configuration Response`. +The following example shows how an OpenID Connect Provider can be configured with the `issuer-uri`: [source,properties,indent=0] ---- spring.security.oauth2.client.provider.oidc-provider.issuer-uri=https://dev-123456.oktapreview.com/oauth2/default/ ---- - - -By default, Spring Security's `OAuth2LoginAuthenticationFilter` only processes URLs -matching `/login/oauth2/code/*`. If you want to customize the `redirect-uri` to -use a different pattern, you need to provide configuration to process that custom pattern. -For example, for servlet applications, you can add your own `WebSecurityConfigurerAdapter` that resembles the -following: +By default, Spring Security's `OAuth2LoginAuthenticationFilter` only processes URLs matching `/login/oauth2/code/*`. +If you want to customize the `redirect-uri` to use a different pattern, you need to provide configuration to process that custom pattern. +For example, for servlet applications, you can add your own `WebSecurityConfigurerAdapter` that resembles the following: [source,java,indent=0] ---- @@ -3482,13 +2938,10 @@ public class OAuth2LoginSecurityConfig extends WebSecurityConfigurerAdapter { [[boot-features-security-oauth2-common-providers]] ===== OAuth2 client registration for common providers -For common OAuth2 and OpenID providers, including Google, Github, Facebook, and Okta, -we provide a set of provider defaults (`google`, `github`, `facebook`, and `okta`, -respectively). +For common OAuth2 and OpenID providers, including Google, Github, Facebook, and Okta, we provide a set of provider defaults (`google`, `github`, `facebook`, and `okta`, respectively). -If you do not need to customize these providers, you can set the `provider` attribute to -the one for which you need to infer defaults. Also, if the key for the client registration matches a -default supported provider, Spring Boot infers that as well. +If you do not need to customize these providers, you can set the `provider` attribute to the one for which you need to infer defaults. +Also, if the key for the client registration matches a default supported provider, Spring Boot infers that as well. In other words, the two configurations in the following example use the Google provider: @@ -3506,9 +2959,7 @@ In other words, the two configurations in the following example use the Google p [[boot-features-security-oauth2-server]] ==== Resource Server -If you have `spring-security-oauth2-resource-server` on your classpath, Spring Boot can -set up an OAuth2 Resource Server as long as a JWK Set URI or OIDC Issuer URI is specified, -as shown in the following examples: +If you have `spring-security-oauth2-resource-server` on your classpath, Spring Boot can set up an OAuth2 Resource Server as long as a JWK Set URI or OIDC Issuer URI is specified, as shown in the following examples: [source,properties,indent=0] ---- @@ -3522,96 +2973,71 @@ as shown in the following examples: The same properties are applicable for both servlet and reactive applications. -Alternatively, you can define your own `JwtDecoder` bean for servlet applications -or a `ReactiveJwtDecoder` for reactive applications. +Alternatively, you can define your own `JwtDecoder` bean for servlet applications or a `ReactiveJwtDecoder` for reactive applications. ==== Authorization Server -Currently, Spring Security does not provide support for implementing an OAuth 2.0 -Authorization Server. However, this functionality is available from -the https://projects.spring.io/spring-security-oauth/[Spring Security OAuth] project, -which will eventually be superseded by Spring Security completely. Until then, you can -use the `spring-security-oauth2-autoconfigure` module to easily set up an OAuth 2.0 authorization server; -see its https://docs.spring.io/spring-security-oauth2-boot[documentation] for instructions. +Currently, Spring Security does not provide support for implementing an OAuth 2.0 Authorization Server. +However, this functionality is available from the https://projects.spring.io/spring-security-oauth/[Spring Security OAuth] project, which will eventually be superseded by Spring Security completely. +Until then, you can use the `spring-security-oauth2-autoconfigure` module to easily set up an OAuth 2.0 authorization server; see its https://docs.spring.io/spring-security-oauth2-boot[documentation] for instructions. [[boot-features-security-actuator]] === Actuator Security -For security purposes, all actuators other than `/health` and `/info` are disabled by -default. The `management.endpoints.web.exposure.include` property can be used to enable -the actuators. +For security purposes, all actuators other than `/health` and `/info` are disabled by default. +The `management.endpoints.web.exposure.include` property can be used to enable the actuators. -If Spring Security is on the classpath and no other WebSecurityConfigurerAdapter is -present, all actuators other than `/health` and `/info` are secured by Spring Boot -auto-configuration. If you define a custom `WebSecurityConfigurerAdapter`, Spring Boot -auto-configuration will back off and you will be in full control of actuator access rules. +If Spring Security is on the classpath and no other WebSecurityConfigurerAdapter is present, all actuators other than `/health` and `/info` are secured by Spring Boot auto-configuration. +If you define a custom `WebSecurityConfigurerAdapter`, Spring Boot auto-configuration will back off and you will be in full control of actuator access rules. -NOTE: Before setting the `management.endpoints.web.exposure.include`, ensure that the -exposed actuators do not contain sensitive information and/or are secured by placing them -behind a firewall or by something like Spring Security. +NOTE: Before setting the `management.endpoints.web.exposure.include`, ensure that the exposed actuators do not contain sensitive information and/or are secured by placing them behind a firewall or by something like Spring Security. [[boot-features-security-csrf]] ==== Cross Site Request Forgery Protection -Since Spring Boot relies on Spring Security's defaults, CSRF protection is turned on by -default. This means that the actuator endpoints that require a `POST` (shutdown and -loggers endpoints), `PUT` or `DELETE` will get a 403 forbidden error when the default -security configuration is in use. +Since Spring Boot relies on Spring Security's defaults, CSRF protection is turned on by default. +This means that the actuator endpoints that require a `POST` (shutdown and loggers endpoints), `PUT` or `DELETE` will get a 403 forbidden error when the default security configuration is in use. -NOTE: We recommend disabling CSRF protection completely only if you are creating a service -that is used by non-browser clients. +NOTE: We recommend disabling CSRF protection completely only if you are creating a service that is used by non-browser clients. -Additional information about CSRF protection can be found in the -{spring-security-reference}#csrf[Spring Security Reference Guide]. +Additional information about CSRF protection can be found in the {spring-security-reference}#csrf[Spring Security Reference Guide]. [[boot-features-sql]] == Working with SQL Databases -The {spring-framework}[Spring Framework] provides extensive support for working with SQL -databases, from direct JDBC access using `JdbcTemplate` to complete "`object relational -mapping`" technologies such as Hibernate. {spring-data}[Spring Data] provides an -additional level of functionality: creating `Repository` implementations directly from -interfaces and using conventions to generate queries from your method names. +The {spring-framework}[Spring Framework] provides extensive support for working with SQL databases, from direct JDBC access using `JdbcTemplate` to complete "`object relational mapping`" technologies such as Hibernate. +{spring-data}[Spring Data] provides an additional level of functionality: creating `Repository` implementations directly from interfaces and using conventions to generate queries from your method names. [[boot-features-configure-datasource]] === Configure a DataSource -Java's `javax.sql.DataSource` interface provides a standard method of working with -database connections. Traditionally, a 'DataSource' uses a `URL` along with some -credentials to establish a database connection. +Java's `javax.sql.DataSource` interface provides a standard method of working with database connections. +Traditionally, a 'DataSource' uses a `URL` along with some credentials to establish a database connection. -TIP: See <> for more -advanced examples, typically to take full control over the configuration of the -DataSource. +TIP: See <> for more advanced examples, typically to take full control over the configuration of the DataSource. [[boot-features-embedded-database-support]] ==== Embedded Database Support It is often convenient to develop applications by using an in-memory embedded database. -Obviously, in-memory databases do not provide persistent storage. You need to populate -your database when your application starts and be prepared to throw away data when your -application ends. +Obviously, in-memory databases do not provide persistent storage. +You need to populate your database when your application starts and be prepared to throw away data when your application ends. -TIP: The "`How-to`" section includes a <>. +TIP: The "`How-to`" section includes a <>. -Spring Boot can auto-configure embedded https://www.h2database.com[H2], -http://hsqldb.org/[HSQL], and https://db.apache.org/derby/[Derby] databases. You need not -provide any connection URLs. You need only include a build dependency to the embedded -database that you want to use. +Spring Boot can auto-configure embedded https://www.h2database.com[H2], http://hsqldb.org/[HSQL], and https://db.apache.org/derby/[Derby] databases. +You need not provide any connection URLs. You need only include a build dependency to the embedded database that you want to use. [NOTE] ==== -If you are using this feature in your tests, you may notice that the same database is -reused by your whole test suite regardless of the number of application contexts that you -use. If you want to make sure that each context has a separate embedded database, you -should set `spring.datasource.generate-unique-name` to `true`. +If you are using this feature in your tests, you may notice that the same database is reused by your whole test suite regardless of the number of application contexts that you use. +If you want to make sure that each context has a separate embedded database, you should set `spring.datasource.generate-unique-name` to `true`. ==== For example, the typical POM dependencies would be as follows: @@ -3629,44 +3055,36 @@ For example, the typical POM dependencies would be as follows: ---- -NOTE: You need a dependency on `spring-jdbc` for an embedded database to be -auto-configured. In this example, it is pulled in transitively through -`spring-boot-starter-data-jpa`. +NOTE: You need a dependency on `spring-jdbc` for an embedded database to be auto-configured. +In this example, it is pulled in transitively through `spring-boot-starter-data-jpa`. -TIP: If, for whatever reason, you do configure the connection URL for an embedded -database, take care to ensure that the database's automatic shutdown is disabled. If you -use H2, you should use `DB_CLOSE_ON_EXIT=FALSE` to do so. If you use HSQLDB, you should -ensure that `shutdown=true` is not used. Disabling the database's automatic shutdown lets -Spring Boot control when the database is closed, thereby ensuring that it happens once -access to the database is no longer needed. +TIP: If, for whatever reason, you do configure the connection URL for an embedded database, take care to ensure that the database's automatic shutdown is disabled. +If you use H2, you should use `DB_CLOSE_ON_EXIT=FALSE` to do so. +If you use HSQLDB, you should ensure that `shutdown=true` is not used. +Disabling the database's automatic shutdown lets Spring Boot control when the database is closed, thereby ensuring that it happens once access to the database is no longer needed. [[boot-features-connect-to-production-database]] ==== Connection to a Production Database -Production database connections can also be auto-configured by using a pooling -`DataSource`. Spring Boot uses the following algorithm for choosing a specific -implementation: +Production database connections can also be auto-configured by using a pooling `DataSource`. +Spring Boot uses the following algorithm for choosing a specific implementation: -. We prefer https://github.com/brettwooldridge/HikariCP[HikariCP] for its performance and -concurrency. If HikariCP is available, we always choose it. +. We prefer https://github.com/brettwooldridge/HikariCP[HikariCP] for its performance and concurrency. + If HikariCP is available, we always choose it. . Otherwise, if the Tomcat pooling `DataSource` is available, we use it. -. If neither HikariCP nor the Tomcat pooling datasource are available and if -https://commons.apache.org/proper/commons-dbcp/[Commons DBCP2] is available, we use it. +. If neither HikariCP nor the Tomcat pooling datasource are available and if https://commons.apache.org/proper/commons-dbcp/[Commons DBCP2] is available, we use it. -If you use the `spring-boot-starter-jdbc` or `spring-boot-starter-data-jpa` "`starters`", -you automatically get a dependency to `HikariCP`. +If you use the `spring-boot-starter-jdbc` or `spring-boot-starter-data-jpa` "`starters`", you automatically get a dependency to `HikariCP`. -NOTE: You can bypass that algorithm completely and specify the connection pool to use by -setting the `spring.datasource.type` property. This is especially important if you run -your application in a Tomcat container, as `tomcat-jdbc` is provided by default. +NOTE: You can bypass that algorithm completely and specify the connection pool to use by setting the `spring.datasource.type` property. +This is especially important if you run your application in a Tomcat container, as `tomcat-jdbc` is provided by default. -TIP: Additional connection pools can always be configured manually. If you define your -own `DataSource` bean, auto-configuration does not occur. +TIP: Additional connection pools can always be configured manually. +If you define your own `DataSource` bean, auto-configuration does not occur. -DataSource configuration is controlled by external configuration properties in -`+spring.datasource.*+`. For example, you might declare the following section in -`application.properties`: +DataSource configuration is controlled by external configuration properties in `+spring.datasource.*+`. +For example, you might declare the following section in `application.properties`: [source,properties,indent=0] ---- @@ -3676,30 +3094,20 @@ DataSource configuration is controlled by external configuration properties in spring.datasource.driver-class-name=com.mysql.jdbc.Driver ---- -NOTE: You should at least specify the URL by setting the `spring.datasource.url` -property. Otherwise, Spring Boot tries to auto-configure an embedded database. +NOTE: You should at least specify the URL by setting the `spring.datasource.url` property. +Otherwise, Spring Boot tries to auto-configure an embedded database. -TIP: You often do not need to specify the `driver-class-name`, since Spring Boot can -deduce it for most databases from the `url`. +TIP: You often do not need to specify the `driver-class-name`, since Spring Boot can deduce it for most databases from the `url`. -NOTE: For a pooling `DataSource` to be created, we need to be able to verify that a valid -`Driver` class is available, so we check for that before doing anything. In other words, -if you set `spring.datasource.driver-class-name=com.mysql.jdbc.Driver`, then that class -has to be loadable. +NOTE: For a pooling `DataSource` to be created, we need to be able to verify that a valid `Driver` class is available, so we check for that before doing anything. +In other words, if you set `spring.datasource.driver-class-name=com.mysql.jdbc.Driver`, then that class has to be loadable. -See -{sc-spring-boot-autoconfigure}/jdbc/DataSourceProperties.{sc-ext}[`DataSourceProperties`] -for more of the supported options. These are the standard options that work regardless of -the actual implementation. It is also possible to fine-tune implementation-specific -settings by using their respective prefix (`+spring.datasource.hikari.*+`, -`+spring.datasource.tomcat.*+`, and `+spring.datasource.dbcp2.*+`). Refer to the -documentation of the connection pool implementation you are using for more details. - -For instance, if you use the -https://tomcat.apache.org/tomcat-8.0-doc/jdbc-pool.html#Common_Attributes[Tomcat -connection pool], you could customize many additional settings, as shown in the following -example: +See {sc-spring-boot-autoconfigure}/jdbc/DataSourceProperties.{sc-ext}[`DataSourceProperties`] for more of the supported options. +These are the standard options that work regardless of the actual implementation. +It is also possible to fine-tune implementation-specific settings by using their respective prefix (`+spring.datasource.hikari.*+`, `+spring.datasource.tomcat.*+`, and `+spring.datasource.dbcp2.*+`). +Refer to the documentation of the connection pool implementation you are using for more details. +For instance, if you use the https://tomcat.apache.org/tomcat-8.0-doc/jdbc-pool.html#Common_Attributes[Tomcat connection pool], you could customize many additional settings, as shown in the following example: [source,properties,indent=0] ---- @@ -3717,15 +3125,10 @@ example: [[boot-features-connecting-to-a-jndi-datasource]] ==== Connection to a JNDI DataSource -If you deploy your Spring Boot application to an Application Server, you might want to -configure and manage your DataSource by using your Application Server's built-in features -and access it by using JNDI. +If you deploy your Spring Boot application to an Application Server, you might want to configure and manage your DataSource by using your Application Server's built-in features and access it by using JNDI. -The `spring.datasource.jndi-name` property can be used as an alternative to the -`spring.datasource.url`, `spring.datasource.username`, and `spring.datasource.password` -properties to access the `DataSource` from a specific JNDI location. For example, the -following section in `application.properties` shows how you can access a JBoss AS defined -`DataSource`: +The `spring.datasource.jndi-name` property can be used as an alternative to the `spring.datasource.url`, `spring.datasource.username`, and `spring.datasource.password` properties to access the `DataSource` from a specific JNDI location. +For example, the following section in `application.properties` shows how you can access a JBoss AS defined `DataSource`: [source,properties,indent=0] ---- @@ -3736,8 +3139,7 @@ following section in `application.properties` shows how you can access a JBoss A [[boot-features-using-jdbc-template]] === Using JdbcTemplate -Spring's `JdbcTemplate` and `NamedParameterJdbcTemplate` classes are auto-configured, and -you can `@Autowire` them directly into your own beans, as shown in the following example: +Spring's `JdbcTemplate` and `NamedParameterJdbcTemplate` classes are auto-configured, and you can `@Autowire` them directly into your own beans, as shown in the following example: [source,java,indent=0] ---- @@ -3760,46 +3162,40 @@ you can `@Autowire` them directly into your own beans, as shown in the following } ---- -You can customize some properties of the template by using the `spring.jdbc.template.*` -properties, as shown in the following example: +You can customize some properties of the template by using the `spring.jdbc.template.*` properties, as shown in the following example: [source,properties,indent=0] ---- spring.jdbc.template.max-rows=500 ---- -NOTE: The `NamedParameterJdbcTemplate` reuses the same `JdbcTemplate` instance behind the -scenes. If more than one `JdbcTemplate` is defined and no primary candidate exists, the -`NamedParameterJdbcTemplate` is not auto-configured. +NOTE: The `NamedParameterJdbcTemplate` reuses the same `JdbcTemplate` instance behind the scenes. +If more than one `JdbcTemplate` is defined and no primary candidate exists, the `NamedParameterJdbcTemplate` is not auto-configured. [[boot-features-jpa-and-spring-data]] === JPA and Spring Data JPA -The Java Persistence API is a standard technology that lets you "`map`" objects to -relational databases. The `spring-boot-starter-data-jpa` POM provides a quick way to get -started. It provides the following key dependencies: +The Java Persistence API is a standard technology that lets you "`map`" objects to relational databases. +The `spring-boot-starter-data-jpa` POM provides a quick way to get started. It provides the following key dependencies: * Hibernate: One of the most popular JPA implementations. * Spring Data JPA: Makes it easy to implement JPA-based repositories. * Spring ORMs: Core ORM support from the Spring Framework. -TIP: We do not go into too many details of JPA or {spring-data}[Spring Data] here. You can -follow the https://spring.io/guides/gs/accessing-data-jpa/["`Accessing Data with JPA`"] -guide from https://spring.io and read the {spring-data-jpa}[Spring Data JPA] and -https://hibernate.org/orm/documentation/[Hibernate] reference documentation. +TIP: We do not go into too many details of JPA or {spring-data}[Spring Data] here. +You can follow the https://spring.io/guides/gs/accessing-data-jpa/["`Accessing Data with JPA`"] guide from https://spring.io and read the {spring-data-jpa}[Spring Data JPA] and https://hibernate.org/orm/documentation/[Hibernate] reference documentation. [[boot-features-entity-classes]] ==== Entity Classes -Traditionally, JPA "`Entity`" classes are specified in a `persistence.xml` file. With -Spring Boot, this file is not necessary and "`Entity Scanning`" is used instead. By -default, all packages below your main configuration class (the one annotated with -`@EnableAutoConfiguration` or `@SpringBootApplication`) are searched. +Traditionally, JPA "`Entity`" classes are specified in a `persistence.xml` file. +With Spring Boot, this file is not necessary and "`Entity Scanning`" is used instead. +By default, all packages below your main configuration class (the one annotated with `@EnableAutoConfiguration` or `@SpringBootApplication`) are searched. -Any classes annotated with `@Entity`, `@Embeddable`, or `@MappedSuperclass` are -considered. A typical entity class resembles the following example: +Any classes annotated with `@Entity`, `@Embeddable`, or `@MappedSuperclass` are considered. +A typical entity class resembles the following example: [source,java,indent=0] ---- @@ -3847,27 +3243,20 @@ considered. A typical entity class resembles the following example: ---- TIP: You can customize entity scanning locations by using the `@EntityScan` annotation. -See the "`<>`" -how-to. +See the "`<>`" how-to. [[boot-features-spring-data-jpa-repositories]] ==== Spring Data JPA Repositories -{spring-data-jpa}[Spring Data JPA] repositories are interfaces that you can define to -access data. JPA queries are created automatically from your method names. For example, a -`CityRepository` interface might declare a `findAllByState(String state)` method to find -all the cities in a given state. +{spring-data-jpa}[Spring Data JPA] repositories are interfaces that you can define to access data. +JPA queries are created automatically from your method names. +For example, a `CityRepository` interface might declare a `findAllByState(String state)` method to find all the cities in a given state. -For more complex queries, you can annotate your method with Spring Data's -{spring-data-javadoc}/repository/Query.html[`Query`] annotation. +For more complex queries, you can annotate your method with Spring Data's {spring-data-javadoc}/repository/Query.html[`Query`] annotation. -Spring Data repositories usually extend from the -{spring-data-commons-javadoc}/repository/Repository.html[`Repository`] or -{spring-data-commons-javadoc}/repository/CrudRepository.html[`CrudRepository`] -interfaces. If you use auto-configuration, repositories are searched from the package -containing your main configuration class (the one annotated with -`@EnableAutoConfiguration` or `@SpringBootApplication`) down. +Spring Data repositories usually extend from the {spring-data-commons-javadoc}/repository/Repository.html[`Repository`] or {spring-data-commons-javadoc}/repository/CrudRepository.html[`CrudRepository`] interfaces. +If you use auto-configuration, repositories are searched from the package containing your main configuration class (the one annotated with `@EnableAutoConfiguration` or `@SpringBootApplication`) down. The following example shows a typical Spring Data repository interface definition: @@ -3887,124 +3276,96 @@ The following example shows a typical Spring Data repository interface definitio } ---- -Spring Data JPA repositories support three different modes of bootstrapping: default, -deferred, and lazy. To enable deferred or lazy bootstrapping, set the -`spring.data.jpa.repositories.bootstrap-mode` to `deferred` or `lazy` respectively. When -using deferred or lazy bootstrapping, the auto-configured `EntityManagerFactoryBuilder` -will use the context's `AsyncTaskExecutor`, if any, as the bootstrap executor. If more -than one exists, the one named `applicationTaskExecutor` will be used. +Spring Data JPA repositories support three different modes of bootstrapping: default, deferred, and lazy. +To enable deferred or lazy bootstrapping, set the `spring.data.jpa.repositories.bootstrap-mode` to `deferred` or `lazy` respectively. +When using deferred or lazy bootstrapping, the auto-configured `EntityManagerFactoryBuilder` will use the context's `AsyncTaskExecutor`, if any, as the bootstrap executor. +If more than one exists, the one named `applicationTaskExecutor` will be used. -TIP: We have barely scratched the surface of Spring Data JPA. For complete details, see -the https://docs.spring.io/spring-data/jpa/docs/current/reference/html/[Spring Data JPA -reference documentation]. +TIP: We have barely scratched the surface of Spring Data JPA. +For complete details, see the https://docs.spring.io/spring-data/jpa/docs/current/reference/html/[Spring Data JPA reference documentation]. [[boot-features-creating-and-dropping-jpa-databases]] ==== Creating and Dropping JPA Databases -By default, JPA databases are automatically created *only* if you use an embedded -database (H2, HSQL, or Derby). You can explicitly configure JPA settings by using -`+spring.jpa.*+` properties. For example, to create and drop tables you can add the -following line to your `application.properties`: +By default, JPA databases are automatically created *only* if you use an embedded database (H2, HSQL, or Derby). +You can explicitly configure JPA settings by using `+spring.jpa.*+` properties. +For example, to create and drop tables you can add the following line to your `application.properties`: [indent=0] ---- spring.jpa.hibernate.ddl-auto=create-drop ---- -NOTE: Hibernate's own internal property name for this (if you happen to remember it -better) is `hibernate.hbm2ddl.auto`. You can set it, along with other Hibernate native -properties, by using `+spring.jpa.properties.*+` (the prefix is stripped before adding -them to the entity manager). The following line shows an example of setting JPA -properties for Hibernate: +NOTE: Hibernate's own internal property name for this (if you happen to remember it better) is `hibernate.hbm2ddl.auto`. +You can set it, along with other Hibernate native properties, by using `+spring.jpa.properties.*+` (the prefix is stripped before adding them to the entity manager). +The following line shows an example of setting JPA properties for Hibernate: [indent=0] ---- spring.jpa.properties.hibernate.globally_quoted_identifiers=true ---- -The line in the preceding example passes a value of `true` for the -`hibernate.globally_quoted_identifiers` property to the Hibernate entity manager. +The line in the preceding example passes a value of `true` for the `hibernate.globally_quoted_identifiers` property to the Hibernate entity manager. -By default, the DDL execution (or validation) is deferred until the `ApplicationContext` -has started. There is also a `spring.jpa.generate-ddl` flag, but it is not used if -Hibernate auto-configuration is active, because the `ddl-auto` settings are more -fine-grained. +By default, the DDL execution (or validation) is deferred until the `ApplicationContext` has started. +There is also a `spring.jpa.generate-ddl` flag, but it is not used if Hibernate auto-configuration is active, because the `ddl-auto` settings are more fine-grained. [[boot-features-jpa-in-web-environment]] ==== Open EntityManager in View -If you are running a web application, Spring Boot by default registers -{spring-javadoc}/orm/jpa/support/OpenEntityManagerInViewInterceptor.{dc-ext}[`OpenEntityManagerInViewInterceptor`] -to apply the "`Open EntityManager in View`" pattern, to allow for lazy loading in web -views. If you do not want this behavior, you should set `spring.jpa.open-in-view` to -`false` in your `application.properties`. +If you are running a web application, Spring Boot by default registers {spring-javadoc}/orm/jpa/support/OpenEntityManagerInViewInterceptor.{dc-ext}[`OpenEntityManagerInViewInterceptor`] to apply the "`Open EntityManager in View`" pattern, to allow for lazy loading in web views. +If you do not want this behavior, you should set `spring.jpa.open-in-view` to `false` in your `application.properties`. [[boot-features-data-jdbc]] === Spring Data JDBC -Spring Data includes repository support for JDBC and will automatically generate SQL for -the methods on `CrudRepository`. For more advanced queries, a `@Query` annotation is -provided. +Spring Data includes repository support for JDBC and will automatically generate SQL for the methods on `CrudRepository`. +For more advanced queries, a `@Query` annotation is provided. -Spring Boot will auto-configure Spring Data's JDBC repositories when the necessary -dependencies are on the classpath. They can be added to your project with a single -dependency on `spring-boot-starter-data-jdbc`. If necessary, you can take control of -Spring Data JDBC's configuration by adding the `@EnableJdbcRepositories` annotation or a -`JdbcConfiguration` subclass to your application. +Spring Boot will auto-configure Spring Data's JDBC repositories when the necessary dependencies are on the classpath. +They can be added to your project with a single dependency on `spring-boot-starter-data-jdbc`. +If necessary, you can take control of Spring Data JDBC's configuration by adding the `@EnableJdbcRepositories` annotation or a `JdbcConfiguration` subclass to your application. -TIP: For complete details of Spring Data JDBC, please refer to the -https://projects.spring.io/spring-data-jdbc/[reference documentation]. +TIP: For complete details of Spring Data JDBC, please refer to the https://projects.spring.io/spring-data-jdbc/[reference documentation]. [[boot-features-sql-h2-console]] === Using H2's Web Console -The https://www.h2database.com[H2 database] provides a -https://www.h2database.com/html/quickstart.html#h2_console[browser-based console] that -Spring Boot can auto-configure for you. The console is auto-configured when the following -conditions are met: +The https://www.h2database.com[H2 database] provides a https://www.h2database.com/html/quickstart.html#h2_console[browser-based console] that Spring Boot can auto-configure for you. +The console is auto-configured when the following conditions are met: * You are developing a servlet-based web application. * `com.h2database:h2` is on the classpath. -* You are using <>. +* You are using <>. -TIP: If you are not using Spring Boot's developer tools but would still like to make use -of H2's console, you can configure the `spring.h2.console.enabled` property with a value -of `true`. +TIP: If you are not using Spring Boot's developer tools but would still like to make use of H2's console, you can configure the `spring.h2.console.enabled` property with a value of `true`. -NOTE: The H2 console is only intended for use during development, so you should take -care to ensure that `spring.h2.console.enabled` is not set to `true` in production. +NOTE: The H2 console is only intended for use during development, so you should take care to ensure that `spring.h2.console.enabled` is not set to `true` in production. [[boot-features-sql-h2-console-custom-path]] ==== Changing the H2 Console's Path -By default, the console is available at `/h2-console`. You can customize the console's -path by using the `spring.h2.console.path` property. +By default, the console is available at `/h2-console`. You can customize the console's path by using the `spring.h2.console.path` property. [[boot-features-jooq]] === Using jOOQ -jOOQ Object Oriented Querying (https://www.jooq.org/[jOOQ]) is a popular product from -https://www.datageekery.com/[Data Geekery] which generates Java code from your -database and lets you build type-safe SQL queries through its fluent API. Both the -commercial and open source editions can be used with Spring Boot. +jOOQ Object Oriented Querying (https://www.jooq.org/[jOOQ]) is a popular product from https://www.datageekery.com/[Data Geekery] which generates Java code from your database and lets you build type-safe SQL queries through its fluent API. +Both the commercial and open source editions can be used with Spring Boot. ==== Code Generation -In order to use jOOQ type-safe queries, you need to generate Java classes from your -database schema. You can follow the instructions in the -{jooq-manual}/#jooq-in-7-steps-step3[jOOQ user manual]. If you use the -`jooq-codegen-maven` plugin and you also use the `spring-boot-starter-parent` -"`parent POM`", you can safely omit the plugin's `` tag. You can also use Spring -Boot-defined version variables (such as `h2.version`) to declare the plugin's database -dependency. The following listing shows an example: +In order to use jOOQ type-safe queries, you need to generate Java classes from your database schema. +You can follow the instructions in the {jooq-manual}/#jooq-in-7-steps-step3[jOOQ user manual]. +If you use the `jooq-codegen-maven` plugin and you also use the `spring-boot-starter-parent` "`parent POM`", you can safely omit the plugin's `` tag. +You can also use Spring Boot-defined version variables (such as `h2.version`) to declare the plugin's database dependency. The following listing shows an example: [source,xml,indent=0] ---- @@ -4037,9 +3398,8 @@ dependency. The following listing shows an example: ==== Using DSLContext The fluent API offered by jOOQ is initiated through the `org.jooq.DSLContext` interface. -Spring Boot auto-configures a `DSLContext` as a Spring Bean and connects it to your -application `DataSource`. To use the `DSLContext`, you can `@Autowire` it, as shown in -the following example: +Spring Boot auto-configures a `DSLContext` as a Spring Bean and connects it to your application `DataSource`. +To use the `DSLContext`, you can `@Autowire` it, as shown in the following example: [source,java,indent=0] ---- @@ -4058,8 +3418,7 @@ the following example: TIP: The jOOQ manual tends to use a variable named `create` to hold the `DSLContext`. -You can then use the `DSLContext` to construct your queries, as shown in the following -example: +You can then use the `DSLContext` to construct your queries, as shown in the following example: [source,java,indent=0] ---- @@ -4073,19 +3432,16 @@ example: ==== jOOQ SQL Dialect -Unless the `spring.jooq.sql-dialect` property has been configured, Spring Boot determines -the SQL dialect to use for your datasource. If Spring Boot could not detect the dialect, -it uses `DEFAULT`. +Unless the `spring.jooq.sql-dialect` property has been configured, Spring Boot determines the SQL dialect to use for your datasource. +If Spring Boot could not detect the dialect, it uses `DEFAULT`. -NOTE: Spring Boot can only auto-configure dialects supported by the open source version -of jOOQ. +NOTE: Spring Boot can only auto-configure dialects supported by the open source version of jOOQ. ==== Customizing jOOQ -More advanced customizations can be achieved by defining your own `@Bean` definitions, -which is used when the jOOQ `Configuration` is created. You can define beans for the -following jOOQ Types: +More advanced customizations can be achieved by defining your own `@Bean` definitions, which is used when the jOOQ `Configuration` is created. +You can define beans for the following jOOQ Types: * `ConnectionProvider` * `ExecutorProvider` @@ -4097,56 +3453,48 @@ following jOOQ Types: * `VisitListenerProvider` * `TransactionListenerProvider` -You can also create your own `org.jooq.Configuration` `@Bean` if you want to take -complete control of the jOOQ configuration. +You can also create your own `org.jooq.Configuration` `@Bean` if you want to take complete control of the jOOQ configuration. [[boot-features-nosql]] == Working with NoSQL Technologies -Spring Data provides additional projects that help you access a variety of NoSQL -technologies, including: -https://projects.spring.io/spring-data-mongodb/[MongoDB], -https://projects.spring.io/spring-data-neo4j/[Neo4J], -https://github.com/spring-projects/spring-data-elasticsearch/[Elasticsearch], -https://projects.spring.io/spring-data-solr/[Solr], -https://projects.spring.io/spring-data-redis/[Redis], -https://projects.spring.io/spring-data-gemfire/[Gemfire], -https://projects.spring.io/spring-data-cassandra/[Cassandra], -https://projects.spring.io/spring-data-couchbase/[Couchbase] and -https://projects.spring.io/spring-data-ldap/[LDAP]. -Spring Boot provides auto-configuration for Redis, MongoDB, Neo4j, Elasticsearch, Solr -Cassandra, Couchbase, and LDAP. You can make use of the other projects, but you must -configure them yourself. Refer to the appropriate reference documentation at -https://projects.spring.io/spring-data[projects.spring.io/spring-data]. +Spring Data provides additional projects that help you access a variety of NoSQL technologies, including: + +* https://projects.spring.io/spring-data-mongodb/[MongoDB] +* https://projects.spring.io/spring-data-neo4j/[Neo4J] +* https://github.com/spring-projects/spring-data-elasticsearch/[Elasticsearch] +* https://projects.spring.io/spring-data-solr/[Solr] +* https://projects.spring.io/spring-data-redis/[Redis] +* https://projects.spring.io/spring-data-gemfire/[Gemfire] +* https://projects.spring.io/spring-data-cassandra/[Cassandra] +* https://projects.spring.io/spring-data-couchbase/[Couchbase] +* https://projects.spring.io/spring-data-ldap/[LDAP] + +Spring Boot provides auto-configuration for Redis, MongoDB, Neo4j, Elasticsearch, Solr Cassandra, Couchbase, and LDAP. +You can make use of the other projects, but you must configure them yourself. +Refer to the appropriate reference documentation at https://projects.spring.io/spring-data[projects.spring.io/spring-data]. [[boot-features-redis]] === Redis https://redis.io/[Redis] is a cache, message broker, and richly-featured key-value store. -Spring Boot offers basic auto-configuration for the -https://github.com/lettuce-io/lettuce-core/[Lettuce] and -https://github.com/xetorthio/jedis/[Jedis] client libraries and the abstractions on top -of them provided by https://github.com/spring-projects/spring-data-redis[Spring Data -Redis]. +Spring Boot offers basic auto-configuration for the https://github.com/lettuce-io/lettuce-core/[Lettuce] and https://github.com/xetorthio/jedis/[Jedis] client libraries and the abstractions on top of them provided by https://github.com/spring-projects/spring-data-redis[Spring Data Redis]. -There is a `spring-boot-starter-data-redis` "`Starter`" for collecting the dependencies -in a convenient way. By default, it uses -https://github.com/lettuce-io/lettuce-core/[Lettuce]. That starter handles both -traditional and reactive applications. +There is a `spring-boot-starter-data-redis` "`Starter`" for collecting the dependencies in a convenient way. +By default, it uses https://github.com/lettuce-io/lettuce-core/[Lettuce]. +That starter handles both traditional and reactive applications. -TIP: we also provide a `spring-boot-starter-data-redis-reactive` "`Starter`" for -consistency with the other stores with reactive support. +TIP: we also provide a `spring-boot-starter-data-redis-reactive` "`Starter`" for consistency with the other stores with reactive support. [[boot-features-connecting-to-redis]] ==== Connecting to Redis -You can inject an auto-configured `RedisConnectionFactory`, `StringRedisTemplate`, or -vanilla `RedisTemplate` instance as you would any other Spring Bean. By default, the -instance tries to connect to a Redis server at `localhost:6379`. The following listing -shows an example of such a bean: +You can inject an auto-configured `RedisConnectionFactory`, `StringRedisTemplate`, or vanilla `RedisTemplate` instance as you would any other Spring Bean. +By default, the instance tries to connect to a Redis server at `localhost:6379`. +The following listing shows an example of such a bean: [source,java,indent=0] ---- @@ -4165,33 +3513,26 @@ shows an example of such a bean: } ---- -TIP: You can also register an arbitrary number of beans that implement -`LettuceClientConfigurationBuilderCustomizer` for more advanced customizations. If you -use Jedis, `JedisClientConfigurationBuilderCustomizer` is also available. +TIP: You can also register an arbitrary number of beans that implement `LettuceClientConfigurationBuilderCustomizer` for more advanced customizations. +If you use Jedis, `JedisClientConfigurationBuilderCustomizer` is also available. -If you add your own `@Bean` of any of the auto-configured types, it replaces the default -(except in the case of `RedisTemplate`, when the exclusion is based on the bean name, -`redisTemplate`, not its type). By default, if `commons-pool2` is on the classpath, you -get a pooled connection factory. +If you add your own `@Bean` of any of the auto-configured types, it replaces the default (except in the case of `RedisTemplate`, when the exclusion is based on the bean name, `redisTemplate`, not its type). +By default, if `commons-pool2` is on the classpath, you get a pooled connection factory. [[boot-features-mongodb]] === MongoDB -https://www.mongodb.com/[MongoDB] is an open-source NoSQL document database that uses a -JSON-like schema instead of traditional table-based relational data. Spring Boot offers -several conveniences for working with MongoDB, including the -`spring-boot-starter-data-mongodb` and `spring-boot-starter-data-mongodb-reactive` -"`Starters`". +https://www.mongodb.com/[MongoDB] is an open-source NoSQL document database that uses a JSON-like schema instead of traditional table-based relational data. +Spring Boot offers several conveniences for working with MongoDB, including the `spring-boot-starter-data-mongodb` and `spring-boot-starter-data-mongodb-reactive` "`Starters`". [[boot-features-connecting-to-mongodb]] ==== Connecting to a MongoDB Database -To access Mongo databases, you can inject an auto-configured -`org.springframework.data.mongodb.MongoDbFactory`. By default, the instance tries to -connect to a MongoDB server at `mongodb://localhost/test` The following example shows how -to connect to a MongoDB database: +To access Mongo databases, you can inject an auto-configured `org.springframework.data.mongodb.MongoDbFactory`. +By default, the instance tries to connect to a MongoDB server at `mongodb://localhost/test`. +The following example shows how to connect to a MongoDB database: [source,java,indent=0] ---- @@ -4218,16 +3559,15 @@ to connect to a MongoDB database: } ---- -You can set the `spring.data.mongodb.uri` property to change the URL and configure -additional settings such as the _replica set_, as shown in the following example: +You can set the `spring.data.mongodb.uri` property to change the URL and configure additional settings such as the _replica set_, as shown in the following example: [source,properties,indent=0] ---- spring.data.mongodb.uri=mongodb://user:secret@mongo1.example.com:12345,mongo2.example.com:23456/test ---- -Alternatively, as long as you use Mongo 2.x, you can specify a `host`/`port`. For -example, you might declare the following settings in your `application.properties`: +Alternatively, as long as you use Mongo 2.x, you can specify a `host`/`port`. +For example, you might declare the following settings in your `application.properties`: [source,properties,indent=0] ---- @@ -4235,32 +3575,27 @@ example, you might declare the following settings in your `application.propertie spring.data.mongodb.port=27017 ---- -If you have defined your own `MongoClient`, it will be used to auto-configure a suitable -`MongoDbFactory`. Both `com.mongodb.MongoClient` and `com.mongodb.client.MongoClient` -are supported. +If you have defined your own `MongoClient`, it will be used to auto-configure a suitable `MongoDbFactory`. +Both `com.mongodb.MongoClient` and `com.mongodb.client.MongoClient` are supported. -NOTE: If you use the Mongo 3.0 Java driver, `spring.data.mongodb.host` and -`spring.data.mongodb.port` are not supported. In such cases, `spring.data.mongodb.uri` -should be used to provide all of the configuration. +NOTE: If you use the Mongo 3.0 Java driver, `spring.data.mongodb.host` and `spring.data.mongodb.port` are not supported. +In such cases, `spring.data.mongodb.uri` should be used to provide all of the configuration. -TIP: If `spring.data.mongodb.port` is not specified, the default of `27017` is used. You -could delete this line from the example shown earlier. +TIP: If `spring.data.mongodb.port` is not specified, the default of `27017` is used. +You could delete this line from the example shown earlier. + +TIP: If you do not use Spring Data Mongo, you can inject `com.mongodb.MongoClient` beans instead of using `MongoDbFactory`. +If you want to take complete control of establishing the MongoDB connection, you can also declare your own `MongoDbFactory` or `MongoClient` bean. + +NOTE: If you are using the reactive driver, Netty is required for SSL. +The auto-configuration configures this factory automatically if Netty is available and the factory to use hasn't been customized already. -TIP: If you do not use Spring Data Mongo, you can inject `com.mongodb.MongoClient` beans -instead of using `MongoDbFactory`. If you want to take complete control of establishing -the MongoDB connection, you can also declare your own `MongoDbFactory` or `MongoClient` -bean. -NOTE: If you are using the reactive driver, Netty is required for SSL. The -auto-configuration configures this factory automatically if Netty is available and the -factory to use hasn't been customized already. [[boot-features-mongo-template]] ==== MongoTemplate -{spring-data-mongo}[Spring Data MongoDB] provides a -{spring-data-mongo-javadoc}/core/MongoTemplate.html[`MongoTemplate`] class that is very -similar in its design to Spring's `JdbcTemplate`. As with `JdbcTemplate`, Spring Boot -auto-configures a bean for you to inject the template, as follows: +{spring-data-mongo}[Spring Data MongoDB] provides a {spring-data-mongo-javadoc}/core/MongoTemplate.html[`MongoTemplate`] class that is very similar in its design to Spring's `JdbcTemplate`. +As with `JdbcTemplate`, Spring Boot auto-configures a bean for you to inject the template, as follows: [source,java,indent=0] ---- @@ -4283,22 +3618,17 @@ auto-configures a bean for you to inject the template, as follows: } ---- -See the -https://docs.spring.io/spring-data/mongodb/docs/current/api/org/springframework/data/mongodb/core/MongoOperations.html[`MongoOperations` -Javadoc] for complete details. +See the https://docs.spring.io/spring-data/mongodb/docs/current/api/org/springframework/data/mongodb/core/MongoOperations.html[`MongoOperations` Javadoc] for complete details. [[boot-features-spring-data-mongo-repositories]] ==== Spring Data MongoDB Repositories -Spring Data includes repository support for MongoDB. As with the JPA repositories -discussed earlier, the basic principle is that queries are constructed automatically, -based on method names. +Spring Data includes repository support for MongoDB. +As with the JPA repositories discussed earlier, the basic principle is that queries are constructed automatically, based on method names. -In fact, both Spring Data JPA and Spring Data MongoDB share the same common -infrastructure. You could take the JPA example from earlier and, assuming that `City` is -now a Mongo data class rather than a JPA `@Entity`, it works in the same way, as shown -in the following example: +In fact, both Spring Data JPA and Spring Data MongoDB share the same common infrastructure. +You could take the JPA example from earlier and, assuming that `City` is now a Mongo data class rather than a JPA `@Entity`, it works in the same way, as shown in the following example: [source,java,indent=0] ---- @@ -4318,51 +3648,39 @@ in the following example: TIP: You can customize document scanning locations by using the `@EntityScan` annotation. -TIP: For complete details of Spring Data MongoDB, including its rich object mapping -technologies, refer to its https://projects.spring.io/spring-data-mongodb/[reference -documentation]. +TIP: For complete details of Spring Data MongoDB, including its rich object mapping technologies, refer to its https://projects.spring.io/spring-data-mongodb/[reference documentation]. [[boot-features-mongo-embedded]] ==== Embedded Mongo -Spring Boot offers auto-configuration for -https://github.com/flapdoodle-oss/de.flapdoodle.embed.mongo[Embedded Mongo]. To use it in -your Spring Boot application, add a dependency on -`de.flapdoodle.embed:de.flapdoodle.embed.mongo`. +Spring Boot offers auto-configuration for https://github.com/flapdoodle-oss/de.flapdoodle.embed.mongo[Embedded Mongo]. +To use it in your Spring Boot application, add a dependency on `de.flapdoodle.embed:de.flapdoodle.embed.mongo`. -The port that Mongo listens on can be configured by setting the `spring.data.mongodb.port` -property. To use a randomly allocated free port, use a value of 0. The `MongoClient` -created by `MongoAutoConfiguration` is automatically configured to use the randomly -allocated port. +The port that Mongo listens on can be configured by setting the `spring.data.mongodb.port` property. +To use a randomly allocated free port, use a value of 0. +The `MongoClient` created by `MongoAutoConfiguration` is automatically configured to use the randomly allocated port. -NOTE: If you do not configure a custom port, the embedded support uses a random port -(rather than 27017) by default. +NOTE: If you do not configure a custom port, the embedded support uses a random port (rather than 27017) by default. -If you have SLF4J on the classpath, the output produced by Mongo is automatically routed -to a logger named `org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongo`. +If you have SLF4J on the classpath, the output produced by Mongo is automatically routed to a logger named `org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongo`. -You can declare your own `IMongodConfig` and `IRuntimeConfig` beans to take control of -the Mongo instance's configuration and logging routing. +You can declare your own `IMongodConfig` and `IRuntimeConfig` beans to take control of the Mongo instance's configuration and logging routing. [[boot-features-neo4j]] === Neo4j -https://neo4j.com/[Neo4j] is an open-source NoSQL graph database that uses a rich data -model of nodes connected by first class relationships, which is better suited for -connected big data than traditional RDBMS approaches. Spring Boot offers several -conveniences for working with Neo4j, including the `spring-boot-starter-data-neo4j` -"`Starter`". +https://neo4j.com/[Neo4j] is an open-source NoSQL graph database that uses a rich data model of nodes connected by first class relationships, which is better suited for connected big data than traditional RDBMS approaches. +Spring Boot offers several conveniences for working with Neo4j, including the `spring-boot-starter-data-neo4j` "`Starter`". [[boot-features-connecting-to-neo4j]] ==== Connecting to a Neo4j Database -To access a Neo4j server, you can inject an auto-configured -`org.neo4j.ogm.session.Session`. By default, the instance tries to connect to a Neo4j -server at `localhost:7687` using the Bolt protocol. The following example shows how to -inject a Neo4j `Session`: +To access a Neo4j server, you can inject an auto-configured `org.neo4j.ogm.session.Session`. +By default, the instance tries to connect to a Neo4j server at `localhost:7687` using the Bolt protocol. +The following example shows how to inject a Neo4j `Session`: [source,java,indent=0] ---- @@ -4381,8 +3699,7 @@ inject a Neo4j `Session`: } ---- -You can configure the uri and credentials to use by setting the `spring.data.neo4j.*` -properties, as shown in the following example: +You can configure the uri and credentials to use by setting the `spring.data.neo4j.*` properties, as shown in the following example: [source,properties,indent=0] ---- @@ -4391,48 +3708,30 @@ properties, as shown in the following example: spring.data.neo4j.password=secret ---- -You can take full control over the session creation by either adding a -`org.neo4j.ogm.config.Configuration` bean or a `org.neo4j.ogm.session.SessionFactory` -bean. +You can take full control over the session creation by either adding a `org.neo4j.ogm.config.Configuration` bean or a `org.neo4j.ogm.session.SessionFactory` bean. [[boot-features-connecting-to-neo4j-embedded]] ==== Using the Embedded Mode -If you add `org.neo4j:neo4j-ogm-embedded-driver` to the dependencies of your application, -Spring Boot automatically configures an in-process embedded instance of Neo4j that does -not persist any data when your application shuts down. +If you add `org.neo4j:neo4j-ogm-embedded-driver` to the dependencies of your application, Spring Boot automatically configures an in-process embedded instance of Neo4j that does not persist any data when your application shuts down. -[NOTE] -==== -As the embedded Neo4j OGM driver does not provide the Neo4j kernel itself, you have -to declare `org.neo4j:neo4j` as dependency yourself. Refer to -https://neo4j.com/docs/ogm-manual/current/reference/#reference:getting-started[the -Neo4j OGM documentation] for a list of compatible versions. -==== +NOTE: As the embedded Neo4j OGM driver does not provide the Neo4j kernel itself, you have to declare `org.neo4j:neo4j` as dependency yourself. +Refer to https://neo4j.com/docs/ogm-manual/current/reference/#reference:getting-started[the Neo4j OGM documentation] for a list of compatible versions. -The embedded driver takes precedence over the other drivers when there are multiple -drivers on the classpath. You can explicitly disable the embedded mode by setting -`spring.data.neo4j.embedded.enabled=false`. +The embedded driver takes precedence over the other drivers when there are multiple drivers on the classpath. +You can explicitly disable the embedded mode by setting `spring.data.neo4j.embedded.enabled=false`. -<> -automatically make use of an embedded Neo4j instance if the embedded driver and Neo4j -kernel are on the classpath as described above. +<> automatically make use of an embedded Neo4j instance if the embedded driver and Neo4j kernel are on the classpath as described above. -[NOTE] -==== -You can enable persistence for the embedded mode by providing a path to a database file -in your configuration, e.g. `spring.data.neo4j.uri=file://var/tmp/graph.db`. -==== +NOTE: You can enable persistence for the embedded mode by providing a path to a database file in your configuration, e.g. `spring.data.neo4j.uri=file://var/tmp/graph.db`. [[boot-features-neo4j-ogm-session]] ==== Neo4jSession -By default, if you are running a web application, the session is bound to the thread for -the entire processing of the request (that is, it uses the "Open Session in View" -pattern). If you do not want this behavior, add the following line to your -`application.properties` file: +By default, if you are running a web application, the session is bound to the thread for the entire processing of the request (that is, it uses the "Open Session in View" pattern). +If you do not want this behavior, add the following line to your `application.properties` file: [source,properties,indent=0] ---- @@ -4445,10 +3744,8 @@ pattern). If you do not want this behavior, add the following line to your ==== Spring Data Neo4j Repositories Spring Data includes repository support for Neo4j. -Spring Data Neo4j shares the common infrastructure with Spring Data JPA as many other -Spring Data modules do. You could take the JPA example from earlier and define -`City` as Neo4j OGM `@NodeEntity` rather than JPA `@Entity` and the repository -abstraction works in the same way, as shown in the following example: +Spring Data Neo4j shares the common infrastructure with Spring Data JPA as many other Spring Data modules do. +You could take the JPA example from earlier and define `City` as Neo4j OGM `@NodeEntity` rather than JPA `@Entity` and the repository abstraction works in the same way, as shown in the following example: [source,java,indent=0] ---- @@ -4465,43 +3762,35 @@ abstraction works in the same way, as shown in the following example: } ---- -The `spring-boot-starter-data-neo4j` "`Starter`" enables the repository support as well -as transaction management. You can customize the locations to look for repositories and -entities by using `@EnableNeo4jRepositories` and `@EntityScan` respectively on a -`@Configuration`-bean. +The `spring-boot-starter-data-neo4j` "`Starter`" enables the repository support as well as transaction management. +You can customize the locations to look for repositories and entities by using `@EnableNeo4jRepositories` and `@EntityScan` respectively on a `@Configuration`-bean. -TIP: For complete details of Spring Data Neo4j, including its object mapping -technologies, refer to the https://projects.spring.io/spring-data-neo4j/[reference -documentation]. +TIP: For complete details of Spring Data Neo4j, including its object mapping technologies, refer to the https://projects.spring.io/spring-data-neo4j/[reference documentation]. [[boot-features-gemfire]] === Gemfire -https://github.com/spring-projects/spring-data-gemfire[Spring Data Gemfire] provides -convenient Spring-friendly tools for accessing the -https://pivotal.io/big-data/pivotal-gemfire#details[Pivotal Gemfire] data management -platform. There is a `spring-boot-starter-data-gemfire` "`Starter`" for collecting the -dependencies in a convenient way. There is currently no auto-configuration support for -Gemfire, but you can enable Spring Data Repositories with a +https://github.com/spring-projects/spring-data-gemfire[Spring Data Gemfire] provides convenient Spring-friendly tools for accessing the https://pivotal.io/big-data/pivotal-gemfire#details[Pivotal Gemfire] data management platform. +There is a `spring-boot-starter-data-gemfire` "`Starter`" for collecting the dependencies in a convenient way. +There is currently no auto-configuration support for Gemfire, but you can enable Spring Data Repositories with a https://github.com/spring-projects/spring-data-gemfire/blob/master/src/main/java/org/springframework/data/gemfire/repository/config/EnableGemfireRepositories.java[single annotation: `@EnableGemfireRepositories`]. [[boot-features-solr]] === Solr -https://lucene.apache.org/solr/[Apache Solr] is a search engine. Spring Boot offers basic -auto-configuration for the Solr 5 client library and the abstractions on top of it -provided by https://github.com/spring-projects/spring-data-solr[Spring Data Solr]. There -is a `spring-boot-starter-data-solr` "`Starter`" for collecting the dependencies in a -convenient way. +https://lucene.apache.org/solr/[Apache Solr] is a search engine. +Spring Boot offers basic auto-configuration for the Solr 5 client library and the abstractions on top of it provided by https://github.com/spring-projects/spring-data-solr[Spring Data Solr]. +There is a `spring-boot-starter-data-solr` "`Starter`" for collecting the dependencies in a convenient way. + [[boot-features-connecting-to-solr]] ==== Connecting to Solr -You can inject an auto-configured `SolrClient` instance as you would any other Spring -bean. By default, the instance tries to connect to a server at -`http://localhost:8983/solr`. The following example shows how to inject a Solr bean: +You can inject an auto-configured `SolrClient` instance as you would any other Spring bean. +By default, the instance tries to connect to a server at `http://localhost:8983/solr`. +The following example shows how to inject a Solr bean: [source,java,indent=0] ---- @@ -4526,43 +3815,35 @@ If you add your own `@Bean` of type `SolrClient`, it replaces the default. [[boot-features-spring-data-solr-repositories]] ==== Spring Data Solr Repositories -Spring Data includes repository support for Apache Solr. As with the JPA repositories -discussed earlier, the basic principle is that queries are automatically constructed for \ -you based on method names. +Spring Data includes repository support for Apache Solr. +As with the JPA repositories discussed earlier, the basic principle is that queries are automatically constructed for you based on method names. In fact, both Spring Data JPA and Spring Data Solr share the same common infrastructure. -You could take the JPA example from earlier and, assuming that `City` is now a -`@SolrDocument` class rather than a JPA `@Entity`, it works in the same way. +You could take the JPA example from earlier and, assuming that `City` is now a `@SolrDocument` class rather than a JPA `@Entity`, it works in the same way. -TIP: For complete details of Spring Data Solr, refer to the -https://projects.spring.io/spring-data-solr/[reference documentation]. +IP: For complete details of Spring Data Solr, refer to the https://projects.spring.io/spring-data-solr/[reference documentation]. [[boot-features-elasticsearch]] === Elasticsearch -https://www.elastic.co/products/elasticsearch[Elasticsearch] is an open source, -distributed, RESTful search and analytics engine. Spring Boot offers basic -auto-configuration for Elasticsearch. +https://www.elastic.co/products/elasticsearch[Elasticsearch] is an open source, distributed, RESTful search and analytics engine. +Spring Boot offers basic auto-configuration for Elasticsearch. Spring Boot supports several HTTP clients: * The official Java "Low Level" and "High Level" REST clients * https://github.com/searchbox-io/Jest[Jest] -The transport client is still being used by -https://github.com/spring-projects/spring-data-elasticsearch[Spring Data Elasticsearch], -which you can start using with the `spring-boot-starter-data-elasticsearch` "`Starter`". +The transport client is still being used by https://github.com/spring-projects/spring-data-elasticsearch[Spring Data Elasticsearch], which you can start using with the `spring-boot-starter-data-elasticsearch` "`Starter`". + + [[boot-features-connecting-to-elasticsearch-rest]] ==== Connecting to Elasticsearch by REST clients -Elasticsearch ships -https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/index.html[two different REST clients] -that you can use to query a cluster: the "Low Level" client and the "High Level" client. +Elasticsearch ships https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/index.html[two different REST clients] that you can use to query a cluster: the "Low Level" client and the "High Level" client. -If you have the `org.elasticsearch.client:elasticsearch-rest-client` dependency on the -classpath, Spring Boot will auto-configure and register a `RestClient` bean that -by default targets `http://localhost:9200`. +If you have the `org.elasticsearch.client:elasticsearch-rest-client` dependency on the classpath, Spring Boot will auto-configure and register a `RestClient` bean that by default targets `http://localhost:9200`. You can further tune how `RestClient` is configured, as shown in the following example: [source,properties,indent=0] @@ -4572,20 +3853,17 @@ You can further tune how `RestClient` is configured, as shown in the following e spring.elasticsearch.rest.password=secret ---- -You can also register an arbitrary number of beans that implement -`RestClientBuilderCustomizer` for more advanced customizations. +You can also register an arbitrary number of beans that implement `RestClientBuilderCustomizer` for more advanced customizations. To take full control over the registration, define a `RestClient` bean. -If you have the `org.elasticsearch.client:elasticsearch-rest-high-level-client` dependency -on the classpath, Spring Boot will auto-configure a `RestHighLevelClient`, which wraps -any existing `RestClient` bean, reusing its HTTP configuration. +If you have the `org.elasticsearch.client:elasticsearch-rest-high-level-client` dependency on the classpath, Spring Boot will auto-configure a `RestHighLevelClient`, which wraps any existing `RestClient` bean, reusing its HTTP configuration. + [[boot-features-connecting-to-elasticsearch-jest]] ==== Connecting to Elasticsearch by Using Jest -If you have `Jest` on the classpath, you can inject an auto-configured `JestClient` that -by default targets `http://localhost:9200`. You can further tune how the client is -configured, as shown in the following example: +If you have `Jest` on the classpath, you can inject an auto-configured `JestClient` that by default targets `http://localhost:9200`. +You can further tune how the client is configured, as shown in the following example: [source,properties,indent=0] ---- @@ -4595,9 +3873,8 @@ configured, as shown in the following example: spring.elasticsearch.jest.password=secret ---- -You can also register an arbitrary number of beans that implement -`HttpClientConfigBuilderCustomizer` for more advanced customizations. The following -example tunes additional HTTP settings: +You can also register an arbitrary number of beans that implement `HttpClientConfigBuilderCustomizer` for more advanced customizations. +The following example tunes additional HTTP settings: [source,java,indent=0] ---- @@ -4611,10 +3888,8 @@ To take full control over the registration, define a `JestClient` bean. [[boot-features-connecting-to-elasticsearch-spring-data]] ==== Connecting to Elasticsearch by Using Spring Data To connect to Elasticsearch, you must provide the address of one or more cluster nodes. -The address can be specified by setting the `spring.data.elasticsearch.cluster-nodes` -property to a comma-separated `host:port` list. With this configuration in place, an -`ElasticsearchTemplate` or `TransportClient` can be injected like any other Spring bean, -as shown in the following example: +The address can be specified by setting the `spring.data.elasticsearch.cluster-nodes` property to a comma-separated `host:port` list. +With this configuration in place, an `ElasticsearchTemplate` or `TransportClient` can be injected like any other Spring bean, as shown in the following example: [source,properties,indent=0] ---- @@ -4637,44 +3912,34 @@ as shown in the following example: } ---- -If you add your own `ElasticsearchTemplate` or `TransportClient` `@Bean`, it replaces the -default. +If you add your own `ElasticsearchTemplate` or `TransportClient` `@Bean`, it replaces the default. [[boot-features-spring-data-elasticsearch-repositories]] ==== Spring Data Elasticsearch Repositories -Spring Data includes repository support for Elasticsearch. As with the JPA repositories -discussed earlier, the basic principle is that queries are constructed for you -automatically based on method names. +Spring Data includes repository support for Elasticsearch. +As with the JPA repositories discussed earlier, the basic principle is that queries are constructed for you automatically based on method names. -In fact, both Spring Data JPA and Spring Data Elasticsearch share the same common -infrastructure. You could take the JPA example from earlier and, assuming that `City` is -now an Elasticsearch `@Document` class rather than a JPA `@Entity`, it works in the same -way. +In fact, both Spring Data JPA and Spring Data Elasticsearch share the same common infrastructure. +You could take the JPA example from earlier and, assuming that `City` is now an Elasticsearch `@Document` class rather than a JPA `@Entity`, it works in the same way. -TIP: For complete details of Spring Data Elasticsearch, refer to the -https://docs.spring.io/spring-data/elasticsearch/docs/[reference documentation]. +TIP: For complete details of Spring Data Elasticsearch, refer to the https://docs.spring.io/spring-data/elasticsearch/docs/[reference documentation]. [[boot-features-cassandra]] === Cassandra -https://cassandra.apache.org/[Cassandra] is an open source, distributed database -management system designed to handle large amounts of data across many commodity servers. -Spring Boot offers auto-configuration for Cassandra and the abstractions on top of it -provided by https://github.com/spring-projects/spring-data-cassandra[Spring Data -Cassandra]. There is a `spring-boot-starter-data-cassandra` "`Starter`" for collecting -the dependencies in a convenient way. +https://cassandra.apache.org/[Cassandra] is an open source, distributed database management system designed to handle large amounts of data across many commodity servers. +Spring Boot offers auto-configuration for Cassandra and the abstractions on top of it provided by https://github.com/spring-projects/spring-data-cassandra[Spring Data Cassandra]. +There is a `spring-boot-starter-data-cassandra` "`Starter`" for collecting the dependencies in a convenient way. [[boot-features-connecting-to-cassandra]] ==== Connecting to Cassandra -You can inject an auto-configured `CassandraTemplate` or a Cassandra `Session` instance -as you would with any other Spring Bean. The `spring.data.cassandra.*` properties can be -used to customize the connection. Generally, you provide `keyspace-name` and -`contact-points` properties, as shown in the following example: +You can inject an auto-configured `CassandraTemplate` or a Cassandra `Session` instance as you would with any other Spring Bean. +The `spring.data.cassandra.*` properties can be used to customize the connection. Generally, you provide `keyspace-name` and `contact-points` properties, as shown in the following example: [source,properties,indent=0] ---- @@ -4682,8 +3947,7 @@ used to customize the connection. Generally, you provide `keyspace-name` and spring.data.cassandra.contact-points=cassandrahost1,cassandrahost2 ---- -You can also register an arbitrary number of beans that implement -`ClusterBuilderCustomizer` for more advanced customizations. +You can also register an arbitrary number of beans that implement `ClusterBuilderCustomizer` for more advanced customizations. The following code listing shows how to inject a Cassandra bean: @@ -4710,32 +3974,26 @@ If you add your own `@Bean` of type `CassandraTemplate`, it replaces the default [[boot-features-spring-data-cassandra-repositories]] ==== Spring Data Cassandra Repositories -Spring Data includes basic repository support for Cassandra. Currently, this is more -limited than the JPA repositories discussed earlier and needs to annotate finder methods -with `@Query`. +Spring Data includes basic repository support for Cassandra. +Currently, this is more limited than the JPA repositories discussed earlier and needs to annotate finder methods with `@Query`. -TIP: For complete details of Spring Data Cassandra, refer to the -https://docs.spring.io/spring-data/cassandra/docs/[reference documentation]. +TIP: For complete details of Spring Data Cassandra, refer to the https://docs.spring.io/spring-data/cassandra/docs/[reference documentation]. [[boot-features-couchbase]] === Couchbase -https://www.couchbase.com/[Couchbase] is an open-source, distributed, multi-model NoSQL -document-oriented database that is optimized for interactive applications. Spring Boot -offers auto-configuration for Couchbase and the abstractions on top of it provided by -https://github.com/spring-projects/spring-data-couchbase[Spring Data Couchbase]. There are -`spring-boot-starter-data-couchbase` and `spring-boot-starter-data-couchbase-reactive` -"`Starters`" for collecting the dependencies in a convenient way. +https://www.couchbase.com/[Couchbase] is an open-source, distributed, multi-model NoSQL document-oriented database that is optimized for interactive applications. +Spring Boot offers auto-configuration for Couchbase and the abstractions on top of it provided by https://github.com/spring-projects/spring-data-couchbase[Spring Data Couchbase]. +There are `spring-boot-starter-data-couchbase` and `spring-boot-starter-data-couchbase-reactive` "`Starters`" for collecting the dependencies in a convenient way. [[boot-features-connecting-to-couchbase]] ==== Connecting to Couchbase You can get a `Bucket` and `Cluster` by adding the Couchbase SDK and some configuration. -The `spring.couchbase.*` properties can be used to customize the connection. Generally, -you provide the bootstrap hosts, bucket name, and password, as shown in the following -example: +The `spring.couchbase.*` properties can be used to customize the connection. +Generally, you provide the bootstrap hosts, bucket name, and password, as shown in the following example: [source,properties,indent=0] ---- @@ -4744,17 +4002,11 @@ example: spring.couchbase.bucket.password=secret ---- -[TIP] -==== -You need to provide _at least_ the bootstrap host(s), in which case the bucket name is -`default` and the password is an empty String. Alternatively, you can define your own -`org.springframework.data.couchbase.config.CouchbaseConfigurer` `@Bean` to take control -over the whole configuration. -==== +TIP: You need to provide _at least_ the bootstrap host(s), in which case the bucket name is `default` and the password is an empty String. +Alternatively, you can define your own `org.springframework.data.couchbase.config.CouchbaseConfigurer` `@Bean` to take control over the whole configuration. -It is also possible to customize some of the `CouchbaseEnvironment` settings. For -instance, the following configuration changes the timeout to use to open a new `Bucket` -and enables SSL support: +It is also possible to customize some of the `CouchbaseEnvironment` settings. +For instance, the following configuration changes the timeout to use to open a new `Bucket` and enables SSL support: [source,properties,indent=0] ---- @@ -4769,14 +4021,10 @@ Check the `spring.couchbase.env.*` properties for more details. [[boot-features-spring-data-couchbase-repositories]] ==== Spring Data Couchbase Repositories -Spring Data includes repository support for Couchbase. For complete details of Spring -Data Couchbase, refer to the -https://docs.spring.io/spring-data/couchbase/docs/current/reference/html/[reference -documentation]. +Spring Data includes repository support for Couchbase. +For complete details of Spring Data Couchbase, refer to the https://docs.spring.io/spring-data/couchbase/docs/current/reference/html/[reference documentation]. -You can inject an auto-configured `CouchbaseTemplate` instance as you would with any -other Spring Bean, provided a _default_ `CouchbaseConfigurer` is available (which -happens when you enable Couchbase support, as explained earlier). +You can inject an auto-configured `CouchbaseTemplate` instance as you would with any other Spring Bean, provided a _default_ `CouchbaseConfigurer` is available (which happens when you enable Couchbase support, as explained earlier). The following examples shows how to inject a Couchbase bean: @@ -4797,16 +4045,14 @@ The following examples shows how to inject a Couchbase bean: } ---- -There are a few beans that you can define in your own configuration to override those -provided by the auto-configuration: +There are a few beans that you can define in your own configuration to override those provided by the auto-configuration: * A `CouchbaseTemplate` `@Bean` with a name of `couchbaseTemplate`. * An `IndexManager` `@Bean` with a name of `couchbaseIndexManager`. * A `CustomConversions` `@Bean` with a name of `couchbaseCustomConversions`. -To avoid hard-coding those names in your own config, you can reuse `BeanNames` provided -by Spring Data Couchbase. For instance, you can customize the converters to use, as -follows: +To avoid hard-coding those names in your own config, you can reuse `BeanNames` provided by Spring Data Couchbase. +For instance, you can customize the converters to use, as follows: [source,java,indent=0] ---- @@ -4823,33 +4069,23 @@ follows: } ---- -TIP: If you want to fully bypass the auto-configuration for Spring Data Couchbase, -provide your own implementation of -`org.springframework.data.couchbase.config.AbstractCouchbaseDataConfiguration`. +TIP: If you want to fully bypass the auto-configuration for Spring Data Couchbase, provide your own implementation of `org.springframework.data.couchbase.config.AbstractCouchbaseDataConfiguration`. [[boot-features-ldap]] === LDAP -https://en.wikipedia.org/wiki/Lightweight_Directory_Access_Protocol[LDAP] (Lightweight -Directory Access Protocol) is an open, vendor-neutral, industry standard application -protocol for accessing and maintaining distributed directory information services over an -IP network. Spring Boot offers auto-configuration for any compliant LDAP server as well -as support for the embedded in-memory LDAP server from -https://www.ldap.com/unboundid-ldap-sdk-for-java[UnboundID]. +https://en.wikipedia.org/wiki/Lightweight_Directory_Access_Protocol[LDAP] (Lightweight Directory Access Protocol) is an open, vendor-neutral, industry standard application protocol for accessing and maintaining distributed directory information services over an IP network. +Spring Boot offers auto-configuration for any compliant LDAP server as well as support for the embedded in-memory LDAP server from https://www.ldap.com/unboundid-ldap-sdk-for-java[UnboundID]. -LDAP abstractions are provided by -https://github.com/spring-projects/spring-data-ldap[Spring Data LDAP]. -There is a `spring-boot-starter-data-ldap` "`Starter`" for collecting the dependencies in -a convenient way. +LDAP abstractions are provided by https://github.com/spring-projects/spring-data-ldap[Spring Data LDAP]. +There is a `spring-boot-starter-data-ldap` "`Starter`" for collecting the dependencies in a convenient way. [[boot-features-ldap-connecting]] ==== Connecting to an LDAP Server -To connect to an LDAP server, make sure you declare a dependency on the -`spring-boot-starter-data-ldap` "`Starter`" or `spring-ldap-core` and then declare the -URLs of your server in your application.properties, as shown in the following example: +To connect to an LDAP server, make sure you declare a dependency on the `spring-boot-starter-data-ldap` "`Starter`" or `spring-ldap-core` and then declare the URLs of your server in your application.properties, as shown in the following example: [source,properties,indent=0] ---- @@ -4858,25 +4094,20 @@ URLs of your server in your application.properties, as shown in the following ex spring.ldap.password=secret ---- -If you need to customize connection settings, you can use the `spring.ldap.base` and -`spring.ldap.base-environment` properties. +If you need to customize connection settings, you can use the `spring.ldap.base` and `spring.ldap.base-environment` properties. -An `LdapContextSource` is auto-configured based on these settings. If you need to customize -it, for instance to use a `PooledContextSource`, you can still inject the auto-configured -`LdapContextSource`. Make sure to flag your customized `ContextSource` as `@Primary` so -that the auto-configured `LdapTemplate` uses it. +An `LdapContextSource` is auto-configured based on these settings. +If you need to customize it, for instance to use a `PooledContextSource`, you can still inject the auto-configured `LdapContextSource`. +Make sure to flag your customized `ContextSource` as `@Primary` so that the auto-configured `LdapTemplate` uses it. [[boot-features-ldap-spring-data-repositories]] ==== Spring Data LDAP Repositories -Spring Data includes repository support for LDAP. For complete details of Spring -Data LDAP, refer to the -https://docs.spring.io/spring-data/ldap/docs/1.0.x/reference/html/[reference -documentation]. +Spring Data includes repository support for LDAP. +For complete details of Spring Data LDAP, refer to the https://docs.spring.io/spring-data/ldap/docs/1.0.x/reference/html/[reference documentation]. -You can also inject an auto-configured `LdapTemplate` instance as you would with any -other Spring Bean, as shown in the following example: +You can also inject an auto-configured `LdapTemplate` instance as you would with any other Spring Bean, as shown in the following example: [source,java,indent=0] @@ -4900,20 +4131,17 @@ other Spring Bean, as shown in the following example: [[boot-features-ldap-embedded]] ==== Embedded In-memory LDAP Server -For testing purposes, Spring Boot supports auto-configuration of an in-memory LDAP server -from https://www.ldap.com/unboundid-ldap-sdk-for-java[UnboundID]. To configure the server, -add a dependency to `com.unboundid:unboundid-ldapsdk` and declare a `base-dn` property, as -follows: +For testing purposes, Spring Boot supports auto-configuration of an in-memory LDAP server from https://www.ldap.com/unboundid-ldap-sdk-for-java[UnboundID]. +To configure the server, add a dependency to `com.unboundid:unboundid-ldapsdk` and declare a `base-dn` property, as follows: [source,properties,indent=0] ---- spring.ldap.embedded.base-dn=dc=spring,dc=io ---- -[NOTE] +NOTE ==== -It is possible to define multiple base-dn values, however, since distinguished names -usually contain commas, they must be defined using the correct notation. +It is possible to define multiple base-dn values, however, since distinguished names usually contain commas, they must be defined using the correct notation. In yaml files, you can use the yaml list notation: @@ -4938,58 +4166,46 @@ By default, the server starts on a random port and triggers the regular LDAP sup There is no need to specify a `spring.ldap.urls` property. If there is a `schema.ldif` file on your classpath, it is used to initialize the server. -If you want to load the initialization script from a different resource, you can also use -the `spring.ldap.embedded.ldif` property. +If you want to load the initialization script from a different resource, you can also use the `spring.ldap.embedded.ldif` property. -By default, a standard schema is used to validate `LDIF` files. You can turn off -validation altogether by setting the `spring.ldap.embedded.validation.enabled` property. -If you have custom attributes, you can use `spring.ldap.embedded.validation.schema` to -define your custom attribute types or object classes. +By default, a standard schema is used to validate `LDIF` files. +You can turn off validation altogether by setting the `spring.ldap.embedded.validation.enabled` property. +If you have custom attributes, you can use `spring.ldap.embedded.validation.schema` to define your custom attribute types or object classes. [[boot-features-influxdb]] === InfluxDB -https://www.influxdata.com/[InfluxDB] is an open-source time series database optimized -for fast, high-availability storage and retrieval of time series data in fields such as -operations monitoring, application metrics, Internet-of-Things sensor data, and real-time -analytics. +https://www.influxdata.com/[InfluxDB] is an open-source time series database optimized for fast, high-availability storage and retrieval of time series data in fields such as operations monitoring, application metrics, Internet-of-Things sensor data, and real-time analytics. [[boot-features-connecting-to-influxdb]] ==== Connecting to InfluxDB -Spring Boot auto-configures an `InfluxDB` instance, provided the `influxdb-java` client -is on the classpath and the URL of the database is set, as shown in the following -example: +Spring Boot auto-configures an `InfluxDB` instance, provided the `influxdb-java` client is on the classpath and the URL of the database is set, as shown in the following example: [source,properties,indent=0] ---- spring.influx.url=https://172.0.0.1:8086 ---- -If the connection to InfluxDB requires a user and password, you can set the -`spring.influx.user` and `spring.influx.password` properties accordingly. +If the connection to InfluxDB requires a user and password, you can set the `spring.influx.user` and `spring.influx.password` properties accordingly. -InfluxDB relies on OkHttp. If you need to tune the http client `InfluxDB` uses behind the -scenes, you can register an `InfluxDbOkHttpClientBuilderProvider` bean. +InfluxDB relies on OkHttp. +If you need to tune the http client `InfluxDB` uses behind the scenes, you can register an `InfluxDbOkHttpClientBuilderProvider` bean. [[boot-features-caching]] == Caching The Spring Framework provides support for transparently adding caching to an application. -At its core, the abstraction applies caching to methods, thus reducing the number of -executions based on the information available in the cache. The caching logic is applied -transparently, without any interference to the invoker. Spring Boot auto-configures the -cache infrastructure as long as caching support is enabled via the `@EnableCaching` -annotation. +At its core, the abstraction applies caching to methods, thus reducing the number of executions based on the information available in the cache. +The caching logic is applied transparently, without any interference to the invoker. +Spring Boot auto-configures the cache infrastructure as long as caching support is enabled via the `@EnableCaching` annotation. -NOTE: Check the {spring-reference}integration.html#cache[relevant section] of the Spring -Framework reference for more details. +NOTE: Check the {spring-reference}integration.html#cache[relevant section] of the Spring Framework reference for more details. -In a nutshell, adding caching to an operation of your service is as easy as adding the -relevant annotation to its method, as shown in the following example: +In a nutshell, adding caching to an operation of your service is as easy as adding the relevant annotation to its method, as shown in the following example: [source,java,indent=0] ---- @@ -5007,47 +4223,33 @@ relevant annotation to its method, as shown in the following example: } ---- -This example demonstrates the use of caching on a potentially costly operation. Before -invoking `computePiDecimal`, the abstraction looks for an entry in the `piDecimals` cache -that matches the `i` argument. If an entry is found, the content in the cache is -immediately returned to the caller, and the method is not invoked. Otherwise, the method -is invoked, and the cache is updated before returning the value. +This example demonstrates the use of caching on a potentially costly operation. +Before invoking `computePiDecimal`, the abstraction looks for an entry in the `piDecimals` cache that matches the `i` argument. +If an entry is found, the content in the cache is immediately returned to the caller, and the method is not invoked. +Otherwise, the method is invoked, and the cache is updated before returning the value. -CAUTION: You can also use the standard JSR-107 (JCache) annotations (such as -`@CacheResult`) transparently. However, we strongly advise you to not mix and match the -Spring Cache and JCache annotations. +CAUTION: You can also use the standard JSR-107 (JCache) annotations (such as `@CacheResult`) transparently. +However, we strongly advise you to not mix and match the Spring Cache and JCache annotations. -If you do not add any specific cache library, Spring Boot auto-configures a -<> that uses concurrent maps in -memory. When a cache is required (such as `piDecimals` in the preceding example), this -provider creates it for you. The simple provider is not really recommended for -production usage, but it is great for getting started and making sure that you understand -the features. When you have made up your mind about the cache provider to use, please -make sure to read its documentation to figure out how to configure the caches that your -application uses. Nearly all providers require you to explicitly configure every cache -that you use in the application. Some offer a way to customize the default caches defined -by the `spring.cache.cache-names` property. +If you do not add any specific cache library, Spring Boot auto-configures a <> that uses concurrent maps in memory. +When a cache is required (such as `piDecimals` in the preceding example), this provider creates it for you. +The simple provider is not really recommended for production usage, but it is great for getting started and making sure that you understand the features. +When you have made up your mind about the cache provider to use, please make sure to read its documentation to figure out how to configure the caches that your application uses. +Nearly all providers require you to explicitly configure every cache that you use in the application. +Some offer a way to customize the default caches defined by the `spring.cache.cache-names` property. -TIP: It is also possible to transparently -{spring-reference}integration.html#cache-annotations-put[update] or -{spring-reference}integration.html#cache-annotations-evict[evict] data from the cache. +TIP: It is also possible to transparently {spring-reference}integration.html#cache-annotations-put[update] or {spring-reference}integration.html#cache-annotations-evict[evict] data from the cache. [[boot-features-caching-provider]] === Supported Cache Providers -The cache abstraction does not provide an actual store and relies on abstraction -materialized by the `org.springframework.cache.Cache` and -`org.springframework.cache.CacheManager` interfaces. +The cache abstraction does not provide an actual store and relies on abstraction materialized by the `org.springframework.cache.Cache` and `org.springframework.cache.CacheManager` interfaces. -If you have not defined a bean of type `CacheManager` or a `CacheResolver` named -`cacheResolver` (see -{spring-javadoc}/cache/annotation/CachingConfigurer.html[`CachingConfigurer`]), -Spring Boot tries to detect the following providers (in the indicated order): +If you have not defined a bean of type `CacheManager` or a `CacheResolver` named `cacheResolver` (see {spring-javadoc}/cache/annotation/CachingConfigurer.html[`CachingConfigurer`]), Spring Boot tries to detect the following providers (in the indicated order): . <> -. <> (EhCache 3, Hazelcast, - Infinispan, and others) +. <> (EhCache 3, Hazelcast, Infinispan, and others) . <> . <> . <> @@ -5056,20 +4258,15 @@ Spring Boot tries to detect the following providers (in the indicated order): . <> . <> -TIP: It is also possible to _force_ a particular cache provider by setting the -`spring.cache.type` property. Use this property if you need to -<> in certain environment -(such as tests). +TIP: It is also possible to _force_ a particular cache provider by setting the `spring.cache.type` property. +Use this property if you need to <> in certain environment (such as tests). -TIP: Use the `spring-boot-starter-cache` "`Starter`" to quickly add basic caching -dependencies. The starter brings in `spring-context-support`. If you add dependencies -manually, you must include `spring-context-support` in order to use the JCache, -EhCache 2.x, or Caffeine support. +TIP: Use the `spring-boot-starter-cache` "`Starter`" to quickly add basic caching dependencies. +The starter brings in `spring-context-support`. +If you add dependencies manually, you must include `spring-context-support` in order to use the JCache, EhCache 2.x, or Caffeine support. -If the `CacheManager` is auto-configured by Spring Boot, you can further tune its -configuration before it is fully initialized by exposing a bean that implements the -`CacheManagerCustomizer` interface. The following example sets a flag to say that null -values should be passed down to the underlying map: +If the `CacheManager` is auto-configured by Spring Boot, you can further tune its configuration before it is fully initialized by exposing a bean that implements the `CacheManagerCustomizer` interface. +The following example sets a flag to say that `null` values should be passed down to the underlying map: [source,java,indent=0] ---- @@ -5084,38 +4281,27 @@ values should be passed down to the underlying map: } ---- -[NOTE] -==== -In the preceding example, an auto-configured `ConcurrentMapCacheManager` is expected. If -that is not the case (either you provided your own config or a different cache provider -was auto-configured), the customizer is not invoked at all. You can have as many -customizers as you want, and you can also order them by using `@Order` or `Ordered`. -==== +NOTE: In the preceding example, an auto-configured `ConcurrentMapCacheManager` is expected. +If that is not the case (either you provided your own config or a different cache provider was auto-configured), the customizer is not invoked at all. +You can have as many customizers as you want, and you can also order them by using `@Order` or `Ordered`. [[boot-features-caching-provider-generic]] ==== Generic -Generic caching is used if the context defines _at least_ one -`org.springframework.cache.Cache` bean. A `CacheManager` wrapping all beans of that type -is created. +Generic caching is used if the context defines _at least_ one `org.springframework.cache.Cache` bean. +A `CacheManager` wrapping all beans of that type is created. [[boot-features-caching-provider-jcache]] ==== JCache (JSR-107) -https://jcp.org/en/jsr/detail?id=107[JCache] is bootstrapped through the presence of a -`javax.cache.spi.CachingProvider` on the classpath (that is, a JSR-107 compliant caching -library exists on the classpath), and the `JCacheCacheManager` is provided by the -`spring-boot-starter-cache` "`Starter`". Various compliant libraries are available, and -Spring Boot provides dependency management for Ehcache 3, Hazelcast, and Infinispan. Any -other compliant library can be added as well. +https://jcp.org/en/jsr/detail?id=107[JCache] is bootstrapped through the presence of a `javax.cache.spi.CachingProvider` on the classpath (that is, a JSR-107 compliant caching library exists on the classpath), and the `JCacheCacheManager` is provided by the `spring-boot-starter-cache` "`Starter`". +Various compliant libraries are available, and Spring Boot provides dependency management for Ehcache 3, Hazelcast, and Infinispan. +Any other compliant library can be added as well. -It might happen that more than one provider is present, in which case the provider must -be explicitly specified. Even if the JSR-107 standard does not enforce a standardized way -to define the location of the configuration file, Spring Boot does its best to -accommodate setting a cache with implementation details, as shown in the following -example: +It might happen that more than one provider is present, in which case the provider must be explicitly specified. +Even if the JSR-107 standard does not enforce a standardized way to define the location of the configuration file, Spring Boot does its best to accommodate setting a cache with implementation details, as shown in the following example: [source,properties,indent=0] ---- @@ -5124,34 +4310,27 @@ example: spring.cache.jcache.config=classpath:acme.xml ---- -NOTE: When a cache library offers both a native implementation and JSR-107 support, -Spring Boot prefers the JSR-107 support, so that the same features are available if you -switch to a different JSR-107 implementation. +NOTE: When a cache library offers both a native implementation and JSR-107 support, Spring Boot prefers the JSR-107 support, so that the same features are available if you switch to a different JSR-107 implementation. -TIP: Spring Boot has <>. If a -single `HazelcastInstance` is available, it is automatically reused for the -`CacheManager` as well, unless the `spring.cache.jcache.config` property is specified. +TIP: Spring Boot has <>. +If a single `HazelcastInstance` is available, it is automatically reused for the `CacheManager` as well, unless the `spring.cache.jcache.config` property is specified. There are two ways to customize the underlying `javax.cache.cacheManager`: -* Caches can be created on startup by setting the `spring.cache.cache-names` property. If -a custom `javax.cache.configuration.Configuration` bean is defined, it is used to -customize them. -* `org.springframework.boot.autoconfigure.cache.JCacheManagerCustomizer` beans are -invoked with the reference of the `CacheManager` for full customization. +* Caches can be created on startup by setting the `spring.cache.cache-names` property. + If a custom `javax.cache.configuration.Configuration` bean is defined, it is used to customize them. +* `org.springframework.boot.autoconfigure.cache.JCacheManagerCustomizer` beans are invoked with the reference of the `CacheManager` for full customization. -TIP: If a standard `javax.cache.CacheManager` bean is defined, it is wrapped -automatically in an `org.springframework.cache.CacheManager` implementation that the -abstraction expects. No further customization is applied to it. +TIP: If a standard `javax.cache.CacheManager` bean is defined, it is wrapped automatically in an `org.springframework.cache.CacheManager` implementation that the abstraction expects. +No further customization is applied to it. [[boot-features-caching-provider-ehcache2]] ==== EhCache 2.x -https://www.ehcache.org/[EhCache] 2.x is used if a file named `ehcache.xml` can be found at -the root of the classpath. If EhCache 2.x is found, the `EhCacheCacheManager` provided by -the `spring-boot-starter-cache` "`Starter`" is used to bootstrap the cache manager. An -alternate configuration file can be provided as well, as shown in the following example: +https://www.ehcache.org/[EhCache] 2.x is used if a file named `ehcache.xml` can be found at the root of the classpath. +If EhCache 2.x is found, the `EhCacheCacheManager` provided by the `spring-boot-starter-cache` "`Starter`" is used to bootstrap the cache manager. +An alternate configuration file can be provided as well, as shown in the following example: [source,properties,indent=0] ---- @@ -5162,56 +4341,44 @@ alternate configuration file can be provided as well, as shown in the following [[boot-features-caching-provider-hazelcast]] ==== Hazelcast - -Spring Boot has <>. If a -`HazelcastInstance` has been auto-configured, it is automatically wrapped in a -`CacheManager`. +Spring Boot has <>. +If a `HazelcastInstance` has been auto-configured, it is automatically wrapped in a `CacheManager`. [[boot-features-caching-provider-infinispan]] ==== Infinispan -https://infinispan.org/[Infinispan] has no default configuration file location, so it must -be specified explicitly. Otherwise, the default bootstrap is used. +https://infinispan.org/[Infinispan] has no default configuration file location, so it must be specified explicitly. +Otherwise, the default bootstrap is used. [source,properties,indent=0] ---- spring.cache.infinispan.config=infinispan.xml ---- -Caches can be created on startup by setting the `spring.cache.cache-names` property. If a -custom `ConfigurationBuilder` bean is defined, it is used to customize the caches. +Caches can be created on startup by setting the `spring.cache.cache-names` property. +If a custom `ConfigurationBuilder` bean is defined, it is used to customize the caches. + +NOTE: The support of Infinispan in Spring Boot is restricted to the embedded mode and is quite basic. +If you want more options, you should use the official Infinispan Spring Boot starter instead. +See https://github.com/infinispan/infinispan-spring-boot[Infinispan's documentation] for more details. -[NOTE] -==== -The support of Infinispan in Spring Boot is restricted to the embedded mode and is quite -basic. If you want more options, you should use the official Infinispan Spring Boot -starter instead. See -https://github.com/infinispan/infinispan-spring-boot[Infinispan's documentation] for more -details. -==== [[boot-features-caching-provider-couchbase]] ==== Couchbase -If the https://www.couchbase.com/[Couchbase] Java client and the `couchbase-spring-cache` -implementation are available and Couchbase is <>, a -`CouchbaseCacheManager` is auto-configured. It is also possible to create additional -caches on startup by setting the `spring.cache.cache-names` property. These caches -operate on the `Bucket` that was auto-configured. You can _also_ create additional caches -on another `Bucket` by using the customizer. Assume you need two caches (`cache1` and -`cache2`) on the "main" `Bucket` and one (`cache3`) cache with a custom time to live of 2 -seconds on the "`another`" `Bucket`. You can create the first two caches through -configuration, as follows: +If the https://www.couchbase.com/[Couchbase] Java client and the `couchbase-spring-cache` implementation are available and Couchbase is <>, a `CouchbaseCacheManager` is auto-configured. +It is also possible to create additional caches on startup by setting the `spring.cache.cache-names` property. +These caches operate on the `Bucket` that was auto-configured. You can _also_ create additional caches on another `Bucket` by using the customizer. +Assume you need two caches (`cache1` and `cache2`) on the "main" `Bucket` and one (`cache3`) cache with a custom time to live of 2 seconds on the "`another`" `Bucket`. +You can create the first two caches through configuration, as follows: [source,properties,indent=0] ---- spring.cache.cache-names=cache1,cache2 ---- -Then you can define a `@Configuration` class to configure the extra `Bucket` and the -`cache3` cache, as follows: - +Then you can define a `@Configuration` class to configure the extra `Bucket` and the `cache3` cache, as follows: [source,java,indent=0] ---- @@ -5240,18 +4407,15 @@ Then you can define a `@Configuration` class to configure the extra `Bucket` and } ---- -This sample configuration reuses the `Cluster` that was created through -auto-configuration. +This sample configuration reuses the `Cluster` that was created through auto-configuration. [[boot-features-caching-provider-redis]] ==== Redis -If https://redis.io/[Redis] is available and configured, a `RedisCacheManager` is -auto-configured. It is possible to create additional caches on startup by setting the -`spring.cache.cache-names` property and cache defaults can be configured by using -`spring.cache.redis.*` properties. For instance, the following configuration creates -`cache1` and `cache2` caches with a _time to live_ of 10 minutes: +If https://redis.io/[Redis] is available and configured, a `RedisCacheManager` is auto-configured. +It is possible to create additional caches on startup by setting the `spring.cache.cache-names` property and cache defaults can be configured by using `spring.cache.redis.*` properties. +For instance, the following configuration creates `cache1` and `cache2` caches with a _time to live_ of 10 minutes: [source,properties,indent=0] ---- @@ -5259,33 +4423,25 @@ auto-configured. It is possible to create additional caches on startup by settin spring.cache.redis.time-to-live=600000 ---- -[NOTE] -==== -By default, a key prefix is added so that, if two separate caches use the same -key, Redis does not have overlapping keys and cannot return invalid values. We strongly -recommend keeping this setting enabled if you create your own `RedisCacheManager`. -==== +NOTE: By default, a key prefix is added so that, if two separate caches use the same key, Redis does not have overlapping keys and cannot return invalid values. +We strongly recommend keeping this setting enabled if you create your own `RedisCacheManager`. -TIP: You can take full control of the configuration by adding a `RedisCacheConfiguration` -`@Bean` of your own. This can be useful if you're looking for customizing the -serialization strategy. +TIP: You can take full control of the configuration by adding a `RedisCacheConfiguration` `@Bean` of your own. +This can be useful if you're looking for customizing the serialization strategy. [[boot-features-caching-provider-caffeine]] ==== Caffeine -https://github.com/ben-manes/caffeine[Caffeine] is a Java 8 rewrite of Guava's cache that -supersedes support for Guava. If Caffeine is present, a `CaffeineCacheManager` (provided -by the `spring-boot-starter-cache` "`Starter`") is auto-configured. Caches can be created -on startup by setting the `spring.cache.cache-names` property and can be customized by one -of the following (in the indicated order): +https://github.com/ben-manes/caffeine[Caffeine] is a Java 8 rewrite of Guava's cache that supersedes support for Guava. +If Caffeine is present, a `CaffeineCacheManager` (provided by the `spring-boot-starter-cache` "`Starter`") is auto-configured. +Caches can be created on startup by setting the `spring.cache.cache-names` property and can be customized by one of the following (in the indicated order): . A cache spec defined by `spring.cache.caffeine.spec` . A `com.github.benmanes.caffeine.cache.CaffeineSpec` bean is defined . A `com.github.benmanes.caffeine.cache.Caffeine` bean is defined -For instance, the following configuration creates `cache1` and `cache2` caches with a -maximum size of 500 and a _time to live_ of 10 minutes +For instance, the following configuration creates `cache1` and `cache2` caches with a maximum size of 500 and a _time to live_ of 10 minutes [source,properties,indent=0] ---- @@ -5293,38 +4449,33 @@ maximum size of 500 and a _time to live_ of 10 minutes spring.cache.caffeine.spec=maximumSize=500,expireAfterAccess=600s ---- -If a `com.github.benmanes.caffeine.cache.CacheLoader` bean is defined, it is -automatically associated to the `CaffeineCacheManager`. Since the `CacheLoader` is going -to be associated with _all_ caches managed by the cache manager, it must be defined as -`CacheLoader`. The auto-configuration ignores any other generic type. +If a `com.github.benmanes.caffeine.cache.CacheLoader` bean is defined, it is automatically associated to the `CaffeineCacheManager`. +Since the `CacheLoader` is going to be associated with _all_ caches managed by the cache manager, it must be defined as `CacheLoader`. +The auto-configuration ignores any other generic type. [[boot-features-caching-provider-simple]] ==== Simple -If none of the other providers can be found, a simple implementation using a -`ConcurrentHashMap` as the cache store is configured. This is the default if no caching -library is present in your application. By default, caches are created as needed, but you -can restrict the list of available caches by setting the `cache-names` property. For -instance, if you want only `cache1` and `cache2` caches, set the `cache-names` property -as follows: +If none of the other providers can be found, a simple implementation using a `ConcurrentHashMap` as the cache store is configured. +This is the default if no caching library is present in your application. +By default, caches are created as needed, but you can restrict the list of available caches by setting the `cache-names` property. +For instance, if you want only `cache1` and `cache2` caches, set the `cache-names` property as follows: [source,properties,indent=0] ---- spring.cache.cache-names=cache1,cache2 ---- -If you do so and your application uses a cache not listed, then it fails at runtime when -the cache is needed, but not on startup. This is similar to the way the "real" cache -providers behave if you use an undeclared cache. +If you do so and your application uses a cache not listed, then it fails at runtime when the cache is needed, but not on startup. +This is similar to the way the "real" cache providers behave if you use an undeclared cache. + [[boot-features-caching-provider-none]] ==== None -When `@EnableCaching` is present in your configuration, a suitable cache configuration is -expected as well. If you need to disable caching altogether in certain environments, -force the cache type to `none` to use a no-op implementation, as shown in the following -example: +When `@EnableCaching` is present in your configuration, a suitable cache configuration is expected as well. +If you need to disable caching altogether in certain environments, force the cache type to `none` to use a no-op implementation, as shown in the following example: [source,properties,indent=0] ---- @@ -5335,42 +4486,32 @@ example: [[boot-features-messaging]] == Messaging -The Spring Framework provides extensive support for integrating with messaging systems, -from simplified use of the JMS API using `JmsTemplate` to a complete infrastructure to -receive messages asynchronously. Spring AMQP provides a similar feature set for the -Advanced Message Queuing Protocol. Spring Boot also provides auto-configuration -options for `RabbitTemplate` and RabbitMQ. Spring WebSocket natively includes support for -STOMP messaging, and Spring Boot has support for that through starters and a small amount -of auto-configuration. Spring Boot also has support for Apache Kafka. +The Spring Framework provides extensive support for integrating with messaging systems, from simplified use of the JMS API using `JmsTemplate` to a complete infrastructure to receive messages asynchronously. +Spring AMQP provides a similar feature set for the Advanced Message Queuing Protocol. +Spring Boot also provides auto-configuration options for `RabbitTemplate` and RabbitMQ. +Spring WebSocket natively includes support for STOMP messaging, and Spring Boot has support for that through starters and a small amount of auto-configuration. +Spring Boot also has support for Apache Kafka. [[boot-features-jms]] === JMS -The `javax.jms.ConnectionFactory` interface provides a standard method of creating a -`javax.jms.Connection` for interacting with a JMS broker. Although Spring needs a -`ConnectionFactory` to work with JMS, you generally need not use it directly yourself and -can instead rely on higher level messaging abstractions. (See the -{spring-reference}integration.html#jms[relevant section] of the Spring Framework -reference documentation for details.) Spring Boot also auto-configures the necessary -infrastructure to send and receive messages. +The `javax.jms.ConnectionFactory` interface provides a standard method of creating a `javax.jms.Connection` for interacting with a JMS broker. +Although Spring needs a `ConnectionFactory` to work with JMS, you generally need not use it directly yourself and can instead rely on higher level messaging abstractions. +(See the {spring-reference}integration.html#jms[relevant section] of the Spring Framework reference documentation for details.) +Spring Boot also auto-configures the necessary infrastructure to send and receive messages. [[boot-features-activemq]] ==== ActiveMQ Support -When https://activemq.apache.org/[ActiveMQ] is available on the classpath, Spring Boot can -also configure a `ConnectionFactory`. If the broker is present, an embedded broker is -automatically started and configured (provided no broker URL is specified through -configuration). +When https://activemq.apache.org/[ActiveMQ] is available on the classpath, Spring Boot can also configure a `ConnectionFactory`. +If the broker is present, an embedded broker is automatically started and configured (provided no broker URL is specified through configuration). -NOTE: If you use `spring-boot-starter-activemq`, the necessary dependencies to connect or -embed an ActiveMQ instance are provided, as is the Spring infrastructure to integrate with -JMS. +NOTE: If you use `spring-boot-starter-activemq`, the necessary dependencies to connect or embed an ActiveMQ instance are provided, as is the Spring infrastructure to integrate with JMS. -ActiveMQ configuration is controlled by external configuration properties in -`+spring.activemq.*+`. For example, you might declare the following section in -`application.properties`: +ActiveMQ configuration is controlled by external configuration properties in `+spring.activemq.*+`. +For example, you might declare the following section in `application.properties`: [source,properties,indent=0] ---- @@ -5379,18 +4520,14 @@ ActiveMQ configuration is controlled by external configuration properties in spring.activemq.password=secret ---- -By default, a `CachingConnectionFactory` wraps the native `ConnectionFactory` with -sensible settings that you can control by external configuration properties in -`+spring.jms.*+`: +By default, a `CachingConnectionFactory` wraps the native `ConnectionFactory` with sensible settings that you can control by external configuration properties in `+spring.jms.*+`: [source,properties,indent=0] ---- spring.jms.cache.session-cache-size=5 ---- -If you'd rather use native pooling, you can do so by adding a dependency to -`org.messaginghub:pooled-jms` and configuring the `JmsPoolConnectionFactory` accordingly, -as shown in the following example: +If you'd rather use native pooling, you can do so by adding a dependency to `org.messaginghub:pooled-jms` and configuring the `JmsPoolConnectionFactory` accordingly, as shown in the following example: [source,properties,indent=0] ---- @@ -5398,36 +4535,24 @@ as shown in the following example: spring.activemq.pool.max-connections=50 ---- -TIP: See -{sc-spring-boot-autoconfigure}/jms/activemq/ActiveMQProperties.{sc-ext}[`ActiveMQProperties`] -for more of the supported options. You can also register an arbitrary number of beans -that implement `ActiveMQConnectionFactoryCustomizer` for more advanced customizations. +TIP: See {sc-spring-boot-autoconfigure}/jms/activemq/ActiveMQProperties.{sc-ext}[`ActiveMQProperties`] for more of the supported options. +You can also register an arbitrary number of beans that implement `ActiveMQConnectionFactoryCustomizer` for more advanced customizations. -By default, ActiveMQ creates a destination if it does not yet exist so that destinations -are resolved against their provided names. +By default, ActiveMQ creates a destination if it does not yet exist so that destinations are resolved against their provided names. [[boot-features-artemis]] ==== Artemis Support -Spring Boot can auto-configure a `ConnectionFactory` when it detects that -https://activemq.apache.org/artemis/[Artemis] is available on the classpath. If the broker -is present, an embedded broker is automatically started and configured (unless the mode -property has been explicitly set). The supported modes are `embedded` (to make explicit -that an embedded broker is required and that an error should occur if the broker is not -available on the classpath) and `native` (to connect to a broker using the `netty` -transport protocol). When the latter is configured, Spring Boot configures a -`ConnectionFactory` that connects to a broker running on the local machine with the -default settings. +Spring Boot can auto-configure a `ConnectionFactory` when it detects that https://activemq.apache.org/artemis/[Artemis] is available on the classpath. +If the broker is present, an embedded broker is automatically started and configured (unless the mode property has been explicitly set). +The supported modes are `embedded` (to make explicit that an embedded broker is required and that an error should occur if the broker is not available on the classpath) and `native` (to connect to a broker using the `netty` transport protocol). +When the latter is configured, Spring Boot configures a `ConnectionFactory` that connects to a broker running on the local machine with the default settings. -NOTE: If you use `spring-boot-starter-artemis`, the necessary dependencies to -connect to an existing Artemis instance are provided, as well as the Spring -infrastructure to integrate with JMS. Adding `org.apache.activemq:artemis-jms-server` to -your application lets you use embedded mode. +NOTE: If you use `spring-boot-starter-artemis`, the necessary dependencies to connect to an existing Artemis instance are provided, as well as the Spring infrastructure to integrate with JMS. Adding `org.apache.activemq:artemis-jms-server` to your application lets you use embedded mode. -Artemis configuration is controlled by external configuration properties in -`+spring.artemis.*+`. For example, you might declare the following section in -`application.properties`: +Artemis configuration is controlled by external configuration properties in `+spring.artemis.*+`. +For example, you might declare the following section in `application.properties`: [source,properties,indent=0] ---- @@ -5438,25 +4563,17 @@ Artemis configuration is controlled by external configuration properties in spring.artemis.password=secret ---- -When embedding the broker, you can choose if you want to enable persistence and list the -destinations that should be made available. These can be specified as a comma-separated -list to create them with the default options, or you can define bean(s) of type -`org.apache.activemq.artemis.jms.server.config.JMSQueueConfiguration` or -`org.apache.activemq.artemis.jms.server.config.TopicConfiguration`, for advanced queue -and topic configurations, respectively. +When embedding the broker, you can choose if you want to enable persistence and list the destinations that should be made available. +These can be specified as a comma-separated list to create them with the default options, or you can define bean(s) of type `org.apache.activemq.artemis.jms.server.config.JMSQueueConfiguration` or `org.apache.activemq.artemis.jms.server.config.TopicConfiguration`, for advanced queue and topic configurations, respectively. -By default, a `CachingConnectionFactory` wraps the native `ConnectionFactory` with -sensible settings that you can control by external configuration properties in -`+spring.jms.*+`: +By default, a `CachingConnectionFactory` wraps the native `ConnectionFactory` with sensible settings that you can control by external configuration properties in `+spring.jms.*+`: [source,properties,indent=0] ---- spring.jms.cache.session-cache-size=5 ---- -If you'd rather use native pooling, you can do so by adding a dependency to -`org.messaginghub:pooled-jms` and configuring the `JmsPoolConnectionFactory` accordingly, -as shown in the following example: +If you'd rather use native pooling, you can do so by adding a dependency to `org.messaginghub:pooled-jms` and configuring the `JmsPoolConnectionFactory` accordingly, as shown in the following example: [source,properties,indent=0] ---- @@ -5464,23 +4581,16 @@ as shown in the following example: spring.artemis.pool.max-connections=50 ---- -See -{sc-spring-boot-autoconfigure}/jms/artemis/ArtemisProperties.{sc-ext}[`ArtemisProperties`] -for more supported options. +See {sc-spring-boot-autoconfigure}/jms/artemis/ArtemisProperties.{sc-ext}[`ArtemisProperties`] for more supported options. -No JNDI lookup is involved, and destinations are resolved against their names, using -either the `name` attribute in the Artemis configuration or the names provided through -configuration. +No JNDI lookup is involved, and destinations are resolved against their names, using either the `name` attribute in the Artemis configuration or the names provided through configuration. [[boot-features-jms-jndi]] ==== Using a JNDI ConnectionFactory -If you are running your application in an application server, Spring Boot tries to -locate a JMS `ConnectionFactory` by using JNDI. By default, the `java:/JmsXA` and -`java:/XAConnectionFactory` location are checked. You can use the `spring.jms.jndi-name` -property if you need to specify an alternative location, as shown in the following -example: +If you are running your application in an application server, Spring Boot tries to locate a JMS `ConnectionFactory` by using JNDI. By default, the `java:/JmsXA` and `java:/XAConnectionFactory` location are checked. +You can use the `spring.jms.jndi-name` property if you need to specify an alternative location, as shown in the following example: [source,properties,indent=0] ---- @@ -5491,8 +4601,7 @@ example: [[boot-features-using-jms-sending]] ==== Sending a Message -Spring's `JmsTemplate` is auto-configured, and you can autowire it directly into your own -beans, as shown in the following example: +Spring's `JmsTemplate` is auto-configured, and you can autowire it directly into your own beans, as shown in the following example: [source,java,indent=0] ---- @@ -5515,26 +4624,23 @@ beans, as shown in the following example: } ---- -NOTE: {spring-javadoc}/jms/core/JmsMessagingTemplate.{dc-ext}[`JmsMessagingTemplate`] can -be injected in a similar manner. If a `DestinationResolver` or a `MessageConverter` bean -is defined, it is associated automatically to the auto-configured `JmsTemplate`. +NOTE: {spring-javadoc}/jms/core/JmsMessagingTemplate.{dc-ext}[`JmsMessagingTemplate`] can be injected in a similar manner. +If a `DestinationResolver` or a `MessageConverter` bean is defined, it is associated automatically to the auto-configured `JmsTemplate`. + [[boot-features-using-jms-receiving]] ==== Receiving a Message -When the JMS infrastructure is present, any bean can be annotated with `@JmsListener` to -create a listener endpoint. If no `JmsListenerContainerFactory` has been defined, a -default one is configured automatically. If a `DestinationResolver` or a -`MessageConverter` beans is defined, it is associated automatically to the default -factory. +When the JMS infrastructure is present, any bean can be annotated with `@JmsListener` to create a listener endpoint. +If no `JmsListenerContainerFactory` has been defined, a default one is configured automatically. +If a `DestinationResolver` or a `MessageConverter` beans is defined, it is associated automatically to the default factory. -By default, the default factory is transactional. If you run in an infrastructure where a -`JtaTransactionManager` is present, it is associated to the listener container by default. -If not, the `sessionTransacted` flag is enabled. In that latter scenario, you can -associate your local data store transaction to the processing of an incoming message by -adding `@Transactional` on your listener method (or a delegate thereof). This ensures that -the incoming message is acknowledged, once the local transaction has completed. This also -includes sending response messages that have been performed on the same JMS session. +By default, the default factory is transactional. +If you run in an infrastructure where a `JtaTransactionManager` is present, it is associated to the listener container by default. +If not, the `sessionTransacted` flag is enabled. +In that latter scenario, you can associate your local data store transaction to the processing of an incoming message by adding `@Transactional` on your listener method (or a delegate thereof). +This ensures that the incoming message is acknowledged, once the local transaction has completed. +This also includes sending response messages that have been performed on the same JMS session. The following component creates a listener endpoint on the `someQueue` destination: @@ -5551,17 +4657,11 @@ The following component creates a listener endpoint on the `someQueue` destinati } ---- -TIP: See {spring-javadoc}/jms/annotation/EnableJms.{dc-ext}[the Javadoc of `@EnableJms`] -for more details. +TIP: See {spring-javadoc}/jms/annotation/EnableJms.{dc-ext}[the Javadoc of `@EnableJms`] for more details. -If you need to create more `JmsListenerContainerFactory` instances or if you want to -override the default, Spring Boot provides a -`DefaultJmsListenerContainerFactoryConfigurer` that you can use to initialize a -`DefaultJmsListenerContainerFactory` with the same settings as the one that is -auto-configured. +If you need to create more `JmsListenerContainerFactory` instances or if you want to override the default, Spring Boot provides a `DefaultJmsListenerContainerFactoryConfigurer` that you can use to initialize a `DefaultJmsListenerContainerFactory` with the same settings as the one that is auto-configured. -For instance, the following example exposes another factory that uses a specific -`MessageConverter`: +For instance, the following example exposes another factory that uses a specific `MessageConverter`: [source,java,indent=0] ---- @@ -5598,25 +4698,22 @@ Then you can use the factory in any `@JmsListener`-annotated method as follows: ---- + [[boot-features-amqp]] === AMQP -The Advanced Message Queuing Protocol (AMQP) is a platform-neutral, wire-level protocol -for message-oriented middleware. The Spring AMQP project applies core Spring concepts to -the development of AMQP-based messaging solutions. Spring Boot offers several conveniences -for working with AMQP through RabbitMQ, including the `spring-boot-starter-amqp` -"`Starter`". +The Advanced Message Queuing Protocol (AMQP) is a platform-neutral, wire-level protocol for message-oriented middleware. +The Spring AMQP project applies core Spring concepts to the development of AMQP-based messaging solutions. +Spring Boot offers several conveniences for working with AMQP through RabbitMQ, including the `spring-boot-starter-amqp` "`Starter`". [[boot-features-rabbitmq]] ==== RabbitMQ support -https://www.rabbitmq.com/[RabbitMQ] is a lightweight, reliable, scalable, and portable -message broker based on the AMQP protocol. Spring uses `RabbitMQ` to communicate through -the AMQP protocol. +https://www.rabbitmq.com/[RabbitMQ] is a lightweight, reliable, scalable, and portable message broker based on the AMQP protocol. +Spring uses `RabbitMQ` to communicate through the AMQP protocol. -RabbitMQ configuration is controlled by external configuration properties in -`+spring.rabbitmq.*+`. For example, you might declare the following section in -`application.properties`: +RabbitMQ configuration is controlled by external configuration properties in `+spring.rabbitmq.*+`. +For example, you might declare the following section in `application.properties`: [source,properties,indent=0] ---- @@ -5626,21 +4723,16 @@ RabbitMQ configuration is controlled by external configuration properties in spring.rabbitmq.password=secret ---- -If a `ConnectionNameStrategy` bean exists in the context, it will be automatically used to -name connections created by the auto-configured `ConnectionFactory`. See -{sc-spring-boot-autoconfigure}/amqp/RabbitProperties.{sc-ext}[`RabbitProperties`] for more -of the supported options. +If a `ConnectionNameStrategy` bean exists in the context, it will be automatically used to name connections created by the auto-configured `ConnectionFactory`. +See {sc-spring-boot-autoconfigure}/amqp/RabbitProperties.{sc-ext}[`RabbitProperties`] for more of the supported options. -TIP: See -https://spring.io/blog/2010/06/14/understanding-amqp-the-protocol-used-by-rabbitmq/[Understanding -AMQP, the protocol used by RabbitMQ] for more details. +TIP: See https://spring.io/blog/2010/06/14/understanding-amqp-the-protocol-used-by-rabbitmq/[Understanding AMQP, the protocol used by RabbitMQ] for more details. [[boot-features-using-amqp-sending]] ==== Sending a Message -Spring's `AmqpTemplate` and `AmqpAdmin` are auto-configured, and you can autowire them -directly into your own beans, as shown in the following example: +Spring's `AmqpTemplate` and `AmqpAdmin` are auto-configured, and you can autowire them directly into your own beans, as shown in the following example: [source,java,indent=0] ---- @@ -5666,15 +4758,12 @@ directly into your own beans, as shown in the following example: } ---- -NOTE: {spring-amqp-javadoc}/rabbit/core/RabbitMessagingTemplate.{dc-ext}[`RabbitMessagingTemplate`] -can be injected in a similar manner. If a `MessageConverter` bean is defined, it is -associated automatically to the auto-configured `AmqpTemplate`. +NOTE: {spring-amqp-javadoc}/rabbit/core/RabbitMessagingTemplate.{dc-ext}[`RabbitMessagingTemplate`] can be injected in a similar manner. +If a `MessageConverter` bean is defined, it is associated automatically to the auto-configured `AmqpTemplate`. -If necessary, any `org.springframework.amqp.core.Queue` that is defined as a bean is -automatically used to declare a corresponding queue on the RabbitMQ instance. +If necessary, any `org.springframework.amqp.core.Queue` that is defined as a bean is automatically used to declare a corresponding queue on the RabbitMQ instance. -To retry operations, you can enable retries on the `AmqpTemplate` (for example, in the -event that the broker connection is lost): +To retry operations, you can enable retries on the `AmqpTemplate` (for example, in the event that the broker connection is lost): [source,properties,indent=0] ---- @@ -5682,19 +4771,16 @@ event that the broker connection is lost): spring.rabbitmq.template.retry.initial-interval=2s ---- -Retries are disabled by default. You can also customize the `RetryTemplate` -programmatically by declaring a `RabbitRetryTemplateCustomizer` bean. +Retries are disabled by default. +You can also customize the `RetryTemplate` programmatically by declaring a `RabbitRetryTemplateCustomizer` bean. [[boot-features-using-amqp-receiving]] ==== Receiving a Message -When the Rabbit infrastructure is present, any bean can be annotated with -`@RabbitListener` to create a listener endpoint. If no `RabbitListenerContainerFactory` -has been defined, a default `SimpleRabbitListenerContainerFactory` is automatically -configured and you can switch to a direct container using the -`spring.rabbitmq.listener.type` property. If a `MessageConverter` or a `MessageRecoverer` -bean is defined, it is automatically associated with the default factory. +When the Rabbit infrastructure is present, any bean can be annotated with `@RabbitListener` to create a listener endpoint. +If no `RabbitListenerContainerFactory` has been defined, a default `SimpleRabbitListenerContainerFactory` is automatically configured and you can switch to a direct container using the `spring.rabbitmq.listener.type` property. +If a `MessageConverter` or a `MessageRecoverer` bean is defined, it is automatically associated with the default factory. The following sample component creates a listener endpoint on the `someQueue` queue: @@ -5711,21 +4797,13 @@ The following sample component creates a listener endpoint on the `someQueue` qu } ---- -TIP: See {spring-amqp-javadoc}/rabbit/annotation/EnableRabbit.{dc-ext}[the Javadoc of -`@EnableRabbit`] for more details. +TIP: See {spring-amqp-javadoc}/rabbit/annotation/EnableRabbit.{dc-ext}[the Javadoc of `@EnableRabbit`] for more details. -If you need to create more `RabbitListenerContainerFactory` instances or if you want to -override the default, Spring Boot provides a -`SimpleRabbitListenerContainerFactoryConfigurer` and a -`DirectRabbitListenerContainerFactoryConfigurer` that you can use to initialize a -`SimpleRabbitListenerContainerFactory` and a `DirectRabbitListenerContainerFactory` with -the same settings as the factories used by the auto-configuration. +If you need to create more `RabbitListenerContainerFactory` instances or if you want to override the default, Spring Boot provides a `SimpleRabbitListenerContainerFactoryConfigurer` and a `DirectRabbitListenerContainerFactoryConfigurer` that you can use to initialize a `SimpleRabbitListenerContainerFactory` and a `DirectRabbitListenerContainerFactory` with the same settings as the factories used by the auto-configuration. -TIP: It does not matter which container type you chose. Those two beans are exposed by -the auto-configuration. +TIP: It does not matter which container type you chose. Those two beans are exposed by the auto-configuration. -For instance, the following configuration class exposes another factory that uses a -specific `MessageConverter`: +For instance, the following configuration class exposes another factory that uses a specific `MessageConverter`: [source,java,indent=0] ---- @@ -5761,30 +4839,23 @@ Then you can use the factory in any `@RabbitListener`-annotated method, as follo } ---- -You can enable retries to handle situations where your listener throws an exception. By -default, `RejectAndDontRequeueRecoverer` is used, but you can define a `MessageRecoverer` -of your own. When retries are exhausted, the message is rejected and either dropped or -routed to a dead-letter exchange if the broker is configured to do so. By default, -retries are disabled. You can also customize the `RetryTemplate` programmatically by -declaring a `RabbitRetryTemplateCustomizer` bean. +You can enable retries to handle situations where your listener throws an exception. +By default, `RejectAndDontRequeueRecoverer` is used, but you can define a `MessageRecoverer` of your own. +When retries are exhausted, the message is rejected and either dropped or routed to a dead-letter exchange if the broker is configured to do so. +By default, retries are disabled. You can also customize the `RetryTemplate` programmatically by declaring a `RabbitRetryTemplateCustomizer` bean. -IMPORTANT: By default, if retries are disabled and the listener throws an exception, the -delivery is retried indefinitely. You can modify this behavior in two ways: Set the -`defaultRequeueRejected` property to `false` so that zero re-deliveries are attempted or -throw an `AmqpRejectAndDontRequeueException` to signal the message should be rejected. -The latter is the mechanism used when retries are enabled and the maximum number of -delivery attempts is reached. +IMPORTANT: By default, if retries are disabled and the listener throws an exception, the delivery is retried indefinitely. +You can modify this behavior in two ways: Set the `defaultRequeueRejected` property to `false` so that zero re-deliveries are attempted or throw an `AmqpRejectAndDontRequeueException` to signal the message should be rejected. +The latter is the mechanism used when retries are enabled and the maximum number of delivery attempts is reached. [[boot-features-kafka]] === Apache Kafka Support -https://kafka.apache.org/[Apache Kafka] is supported by providing auto-configuration of -the `spring-kafka` project. +https://kafka.apache.org/[Apache Kafka] is supported by providing auto-configuration of the `spring-kafka` project. -Kafka configuration is controlled by external configuration properties in -`spring.kafka.*`. For example, you might declare the following section in -`application.properties`: +Kafka configuration is controlled by external configuration properties in `spring.kafka.*`. +For example, you might declare the following section in `application.properties`: [source,properties,indent=0] ---- @@ -5792,18 +4863,16 @@ Kafka configuration is controlled by external configuration properties in spring.kafka.consumer.group-id=myGroup ---- -TIP: To create a topic on startup, add a bean of type `NewTopic`. If the topic already -exists, the bean is ignored. +TIP: To create a topic on startup, add a bean of type `NewTopic`. +If the topic already exists, the bean is ignored. -See {sc-spring-boot-autoconfigure}/kafka/KafkaProperties.{sc-ext}[`KafkaProperties`] -for more supported options. +See {sc-spring-boot-autoconfigure}/kafka/KafkaProperties.{sc-ext}[`KafkaProperties`] for more supported options. [[boot-features-kafka-sending-a-message]] ==== Sending a Message -Spring's `KafkaTemplate` is auto-configured, and you can autowire it directly in your own -beans, as shown in the following example: +Spring's `KafkaTemplate` is auto-configured, and you can autowire it directly in your own beans, as shown in the following example: [source,java,indent=0] ---- @@ -5822,17 +4891,15 @@ public class MyBean { } ---- -NOTE: If the property `spring.kafka.producer.transaction-id-prefix` is defined, a -`KafkaTransactionManager` is automatically configured. Also, if a `RecordMessageConverter` -bean is defined, it is automatically associated to the auto-configured `KafkaTemplate`. +NOTE: If the property `spring.kafka.producer.transaction-id-prefix` is defined, a `KafkaTransactionManager` is automatically configured. +Also, if a `RecordMessageConverter` bean is defined, it is automatically associated to the auto-configured `KafkaTemplate`. + [[boot-features-kafka-receiving-a-message]] ==== Receiving a Message -When the Apache Kafka infrastructure is present, any bean can be annotated with -`@KafkaListener` to create a listener endpoint. If no `KafkaListenerContainerFactory` has -been defined, a default one is automatically configured with keys defined in -`spring.kafka.listener.*`. +When the Apache Kafka infrastructure is present, any bean can be annotated with `@KafkaListener` to create a listener endpoint. +If no `KafkaListenerContainerFactory` has been defined, a default one is automatically configured with keys defined in `spring.kafka.listener.*`. The following component creates a listener endpoint on the `someTopic` topic: @@ -5849,63 +4916,49 @@ The following component creates a listener endpoint on the `someTopic` topic: } ---- -If a `KafkaTransactionManager` bean is defined, it is automatically associated to the -container factory. Similarly, if a `RecordMessageConverter`, `ErrorHandler` or -`AfterRollbackProcessor` bean is defined, it is automatically associated to the default -factory. +If a `KafkaTransactionManager` bean is defined, it is automatically associated to the container factory. +Similarly, if a `RecordMessageConverter`, `ErrorHandler` or `AfterRollbackProcessor` bean is defined, it is automatically associated to the default factory. -TIP: A custom `ChainedKafkaTransactionManager` must be marked `@Primary` as it usually -references the auto-configured `KafkaTransactionManager` bean. +TIP: A custom `ChainedKafkaTransactionManager` must be marked `@Primary` as it usually references the auto-configured `KafkaTransactionManager` bean. [[boot-features-kafka-streams]] ==== Kafka Streams -Spring for Apache Kafka provides a factory bean to create a `StreamsBuilder` object and -manage the lifecycle of its streams. Spring Boot auto-configures the required -`KafkaStreamsConfiguration` bean as long as `kafka-streams` is on the classpath and Kafka -Streams is enabled via the `@EnableKafkaStreams` annotation. +Spring for Apache Kafka provides a factory bean to create a `StreamsBuilder` object and manage the lifecycle of its streams. +Spring Boot auto-configures the required `KafkaStreamsConfiguration` bean as long as `kafka-streams` is on the classpath and Kafka Streams is enabled via the `@EnableKafkaStreams` annotation. Enabling Kafka Streams means that the application id and bootstrap servers must be set. -The former can be configured using `spring.kafka.streams.application-id`, defaulting to -`spring.application.name` if not set. The latter can be set globally or -specifically overridden just for streams. +The former can be configured using `spring.kafka.streams.application-id`, defaulting to `spring.application.name` if not set. +The latter can be set globally or specifically overridden just for streams. -Several additional properties are available using dedicated properties; other arbitrary -Kafka properties can be set using the `spring.kafka.streams.properties` namespace. See -also <> for more information. +Several additional properties are available using dedicated properties; other arbitrary Kafka properties can be set using the `spring.kafka.streams.properties` namespace. +See also <> for more information. -To use the factory bean, simply wire `StreamsBuilder` into your `@Bean` as shown in the -following example: +To use the factory bean, simply wire `StreamsBuilder` into your `@Bean` as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/kafka/KafkaStreamsBeanExample.java[tag=configuration] ---- -By default, the streams managed by the `StreamBuilder` object it creates are started -automatically. You can customize this behaviour using the -`spring.kafka.streams.auto-startup` property. +By default, the streams managed by the `StreamBuilder` object it creates are started automatically. +You can customize this behaviour using the `spring.kafka.streams.auto-startup` property. [[boot-features-kafka-extra-props]] ==== Additional Kafka Properties -The properties supported by auto configuration are shown in -<>. Note that, for the most part, these properties -(hyphenated or camelCase) map directly to the Apache Kafka dotted properties. Refer to the -Apache Kafka documentation for details. +The properties supported by auto configuration are shown in <>. +Note that, for the most part, these properties (hyphenated or camelCase) map directly to the Apache Kafka dotted properties. +Refer to the Apache Kafka documentation for details. -The first few of these properties apply to all components (producers, consumers, admins, -and streams) but can be -specified at the component level if you wish to use different values. -Apache Kafka designates properties with an importance of HIGH, MEDIUM, or LOW. Spring Boot -auto-configuration supports all HIGH importance properties, some selected MEDIUM and LOW -properties, and any properties that do not have a default value. +The first few of these properties apply to all components (producers, consumers, admins, and streams) but can be specified at the component level if you wish to use different values. +Apache Kafka designates properties with an importance of HIGH, MEDIUM, or LOW. +Spring Boot auto-configuration supports all HIGH importance properties, some selected MEDIUM and LOW properties, and any properties that do not have a default value. -Only a subset of the properties supported by Kafka are available directly through the -`KafkaProperties` class. If you wish to configure the producer or consumer with additional -properties that are not directly supported, use the following properties: +Only a subset of the properties supported by Kafka are available directly through the `KafkaProperties` class. +If you wish to configure the producer or consumer with additional properties that are not directly supported, use the following properties: [source,properties,indent=0] ---- @@ -5916,41 +4969,35 @@ properties that are not directly supported, use the following properties: spring.kafka.streams.properties.prop.five=fifth ---- -This sets the common `prop.one` Kafka property to `first` (applies to producers, -consumers and admins), the `prop.two` admin property to `second`, the `prop.three` -consumer property to `third`, the `prop.four` producer property to `fourth` and the -`prop.five` streams property to `fifth`. +This sets the common `prop.one` Kafka property to `first` (applies to producers, consumers and admins), the `prop.two` admin property to `second`, the `prop.three` consumer property to `third`, the `prop.four` producer property to `fourth` and the `prop.five` streams property to `fifth`. You can also configure the Spring Kafka `JsonDeserializer` as follows: [source,properties,indent=0] ---- -spring.kafka.consumer.value-deserializer=org.springframework.kafka.support.serializer.JsonDeserializer -spring.kafka.consumer.properties.spring.json.value.default.type=com.example.Invoice -spring.kafka.consumer.properties.spring.json.trusted.packages=com.example,org.acme + spring.kafka.consumer.value-deserializer=org.springframework.kafka.support.serializer.JsonDeserializer + spring.kafka.consumer.properties.spring.json.value.default.type=com.example.Invoice + spring.kafka.consumer.properties.spring.json.trusted.packages=com.example,org.acme ---- -Similarly, you can disable the `JsonSerializer` default behavior of sending type -information in headers: +Similarly, you can disable the `JsonSerializer` default behavior of sending type information in headers: [source,properties,indent=0] ---- -spring.kafka.producer.value-serializer=org.springframework.kafka.support.serializer.JsonSerializer -spring.kafka.producer.properties.spring.json.add.type.headers=false + spring.kafka.producer.value-serializer=org.springframework.kafka.support.serializer.JsonSerializer + spring.kafka.producer.properties.spring.json.add.type.headers=false ---- -IMPORTANT: Properties set in this way override any configuration item that Spring Boot -explicitly supports. +IMPORTANT: Properties set in this way override any configuration item that Spring Boot explicitly supports. + + [[boot-features-resttemplate]] == Calling REST Services with `RestTemplate` -If you need to call remote REST services from your application, you can use the Spring -Framework's {spring-javadoc}/web/client/RestTemplate.html[`RestTemplate`] class. Since -`RestTemplate` instances often need to be customized before being used, Spring Boot does -not provide any single auto-configured `RestTemplate` bean. It does, however, -auto-configure a `RestTemplateBuilder`, which can be used to create `RestTemplate` -instances when needed. The auto-configured `RestTemplateBuilder` ensures that sensible -`HttpMessageConverters` are applied to `RestTemplate` instances. +If you need to call remote REST services from your application, you can use the Spring Framework's {spring-javadoc}/web/client/RestTemplate.html[`RestTemplate`] class. +Since `RestTemplate` instances often need to be customized before being used, Spring Boot does not provide any single auto-configured `RestTemplate` bean. +It does, however, auto-configure a `RestTemplateBuilder`, which can be used to create `RestTemplate` instances when needed. +The auto-configured `RestTemplateBuilder` ensures that sensible `HttpMessageConverters` are applied to `RestTemplate` instances. The following code shows a typical example: @@ -5972,52 +5019,41 @@ The following code shows a typical example: } ---- -TIP: `RestTemplateBuilder` includes a number of useful methods that can be used to -quickly configure a `RestTemplate`. For example, to add BASIC auth support, you can use -`builder.basicAuthentication("user", "password").build()`. +TIP: `RestTemplateBuilder` includes a number of useful methods that can be used to quickly configure a `RestTemplate`. +For example, to add BASIC auth support, you can use `builder.basicAuthentication("user", "password").build()`. [[boot-features-resttemplate-customization]] === RestTemplate Customization -There are three main approaches to `RestTemplate` customization, depending on how broadly -you want the customizations to apply. +There are three main approaches to `RestTemplate` customization, depending on how broadly you want the customizations to apply. -To make the scope of any customizations as narrow as possible, inject the auto-configured -`RestTemplateBuilder` and then call its methods as required. Each method call returns a -new `RestTemplateBuilder` instance, so the customizations only affect this use of the -builder. +To make the scope of any customizations as narrow as possible, inject the auto-configured `RestTemplateBuilder` and then call its methods as required. +Each method call returns a new `RestTemplateBuilder` instance, so the customizations only affect this use of the builder. To make an application-wide, additive customization, use a `RestTemplateCustomizer` bean. -All such beans are automatically registered with the auto-configured `RestTemplateBuilder` -and are applied to any templates that are built with it. +All such beans are automatically registered with the auto-configured `RestTemplateBuilder` and are applied to any templates that are built with it. -The following example shows a customizer that configures the use of a proxy for all hosts -except `192.168.0.5`: +The following example shows a customizer that configures the use of a proxy for all hosts except `192.168.0.5`: [source,java,indent=0] ---- include::{code-examples}/web/client/RestTemplateProxyCustomizationExample.java[tag=customizer] ---- -Finally, the most extreme (and rarely used) option is to create your own -`RestTemplateBuilder` bean. Doing so switches off the auto-configuration of a -`RestTemplateBuilder` and prevents any `RestTemplateCustomizer` beans from being used. +Finally, the most extreme (and rarely used) option is to create your own `RestTemplateBuilder` bean. +Doing so switches off the auto-configuration of a `RestTemplateBuilder` and prevents any `RestTemplateCustomizer` beans from being used. [[boot-features-webclient]] == Calling REST Services with `WebClient` -If you have Spring WebFlux on your classpath, you can also choose to use `WebClient` to -call remote REST services. Compared to `RestTemplate`, this client has a more functional -feel and is fully reactive. You can learn more about the `WebClient` in the dedicated -{spring-reference}web-reactive.html#webflux-client[section in the Spring Framework docs]. +If you have Spring WebFlux on your classpath, you can also choose to use `WebClient` to call remote REST services. +Compared to `RestTemplate`, this client has a more functional feel and is fully reactive. +You can learn more about the `WebClient` in the dedicated {spring-reference}web-reactive.html#webflux-client[section in the Spring Framework docs]. -Spring Boot creates and pre-configures a `WebClient.Builder` for you; it is strongly -advised to inject it in your components and use it to create `WebClient` instances. -Spring Boot is configuring that builder to share HTTP resources, reflect codecs -setup in the same fashion as the server ones (see -<>), and more. +Spring Boot creates and pre-configures a `WebClient.Builder` for you; it is strongly advised to inject it in your components and use it to create `WebClient` instances. +Spring Boot is configuring that builder to share HTTP resources, reflect codecs setup in the same fashion as the server ones (see <>), and more. The following code shows a typical example: @@ -6044,61 +5080,43 @@ The following code shows a typical example: [[boot-features-webclient-runtime]] === WebClient Runtime -Spring Boot will auto-detect which `ClientHttpConnector` to use to drive `WebClient`, -depending on the libraries available on the application classpath. For now, Reactor -Netty and Jetty RS client are supported. +Spring Boot will auto-detect which `ClientHttpConnector` to use to drive `WebClient`, depending on the libraries available on the application classpath. +For now, Reactor Netty and Jetty RS client are supported. -The `spring-boot-starter-webflux` starter depends on `io.projectreactor.netty:reactor-netty` -by default, which brings both server and client implementations. If you choose to use Jetty -as a reactive server instead, you should add a dependency on the Jetty Reactive HTTP -client library, `org.eclipse.jetty:jetty-reactive-httpclient`. Using the same technology -for server and client has it advantages, as it will automatically share HTTP resources -between client and server. +The `spring-boot-starter-webflux` starter depends on `io.projectreactor.netty:reactor-netty` by default, which brings both server and client implementations. +If you choose to use Jetty as a reactive server instead, you should add a dependency on the Jetty Reactive HTTP client library, `org.eclipse.jetty:jetty-reactive-httpclient`. +Using the same technology for server and client has it advantages, as it will automatically share HTTP resources between client and server. -Developers can override the resource configuration for Jetty and Reactor Netty by providing -a custom `ReactorResourceFactory` or `JettyResourceFactory` bean - this will be applied to -both clients and servers. +Developers can override the resource configuration for Jetty and Reactor Netty by providing a custom `ReactorResourceFactory` or `JettyResourceFactory` bean - this will be applied to both clients and servers. -If you wish to override that choice for the client, you can define your own -`ClientHttpConnector` bean and have full control over the client configuration. +If you wish to override that choice for the client, you can define your own `ClientHttpConnector` bean and have full control over the client configuration. -You can learn more about the -{spring-reference}web-reactive.html#webflux-client-builder[`WebClient` configuration -options in the Spring Framework reference documentation]. +You can learn more about the {spring-reference}web-reactive.html#webflux-client-builder[`WebClient` configuration options in the Spring Framework reference documentation]. [[boot-features-webclient-customization]] === WebClient Customization -There are three main approaches to `WebClient` customization, depending on how broadly you -want the customizations to apply. +There are three main approaches to `WebClient` customization, depending on how broadly you want the customizations to apply. -To make the scope of any customizations as narrow as possible, inject the auto-configured -`WebClient.Builder` and then call its methods as required. `WebClient.Builder` instances -are stateful: Any change on the builder is reflected in all clients subsequently created -with it. If you want to create several clients with the same builder, you can also -consider cloning the builder with `WebClient.Builder other = builder.clone();`. +To make the scope of any customizations as narrow as possible, inject the auto-configured `WebClient.Builder` and then call its methods as required. +`WebClient.Builder` instances are stateful: Any change on the builder is reflected in all clients subsequently created with it. +If you want to create several clients with the same builder, you can also consider cloning the builder with `WebClient.Builder other = builder.clone();`. -To make an application-wide, additive customization to all `WebClient.Builder` instances, -you can declare `WebClientCustomizer` beans and change the `WebClient.Builder` locally at -the point of injection. +To make an application-wide, additive customization to all `WebClient.Builder` instances, you can declare `WebClientCustomizer` beans and change the `WebClient.Builder` locally at the point of injection. -Finally, you can fall back to the original API and use `WebClient.create()`. In that case, -no auto-configuration or `WebClientCustomizer` is applied. +Finally, you can fall back to the original API and use `WebClient.create()`. +In that case, no auto-configuration or `WebClientCustomizer` is applied. [[boot-features-validation]] == Validation -The method validation feature supported by Bean Validation 1.1 is automatically enabled -as long as a JSR-303 implementation (such as Hibernate validator) is on the classpath. -This lets bean methods be annotated with `javax.validation` constraints on their -parameters and/or on their return value. Target classes with such annotated methods need -to be annotated with the `@Validated` annotation at the type level for their methods to -be searched for inline constraint annotations. +The method validation feature supported by Bean Validation 1.1 is automatically enabled as long as a JSR-303 implementation (such as Hibernate validator) is on the classpath. +This lets bean methods be annotated with `javax.validation` constraints on their parameters and/or on their return value. +Target classes with such annotated methods need to be annotated with the `@Validated` annotation at the type level for their methods to be searched for inline constraint annotations. -For instance, the following service triggers the validation of the first argument, making -sure its size is between 8 and 10: +For instance, the following service triggers the validation of the first argument, making sure its size is between 8 and 10: [source,java,indent=0] ---- @@ -6118,23 +5136,15 @@ sure its size is between 8 and 10: [[boot-features-email]] == Sending Email -The Spring Framework provides an easy abstraction for sending email by using the -`JavaMailSender` interface, and Spring Boot provides auto-configuration for it as well as -a starter module. +The Spring Framework provides an easy abstraction for sending email by using the `JavaMailSender` interface, and Spring Boot provides auto-configuration for it as well as a starter module. -TIP: See the {spring-reference}integration.html#mail[reference documentation] for a -detailed explanation of how you can use `JavaMailSender`. +TIP: See the {spring-reference}integration.html#mail[reference documentation] for a detailed explanation of how you can use `JavaMailSender`. -If `spring.mail.host` and the relevant libraries (as defined by -`spring-boot-starter-mail`) are available, a default `JavaMailSender` is created if none -exists. The sender can be further customized by configuration items from the -`spring.mail` namespace. See -{sc-spring-boot-autoconfigure}/mail/MailProperties.{sc-ext}[`MailProperties`] for more -details. +If `spring.mail.host` and the relevant libraries (as defined by `spring-boot-starter-mail`) are available, a default `JavaMailSender` is created if none exists. +The sender can be further customized by configuration items from the `spring.mail` namespace. +See {sc-spring-boot-autoconfigure}/mail/MailProperties.{sc-ext}[`MailProperties`] for more details. -In particular, certain default timeout values are infinite, and you may want to change -that to avoid having a thread blocked by an unresponsive mail server, as shown in the -following example: +In particular, certain default timeout values are infinite, and you may want to change that to avoid having a thread blocked by an unresponsive mail server, as shown in the following example: [source,properties,indent=0] ---- @@ -6156,95 +5166,66 @@ When a `jndi-name` is set, it takes precedence over all other Session-related se [[boot-features-jta]] == Distributed Transactions with JTA -Spring Boot supports distributed JTA transactions across multiple XA resources by using -either an https://www.atomikos.com/[Atomikos] or https://github.com/bitronix/btm[Bitronix] -embedded transaction manager. JTA transactions are also supported when deploying to a -suitable Java EE Application Server. +Spring Boot supports distributed JTA transactions across multiple XA resources by using either an https://www.atomikos.com/[Atomikos] or https://github.com/bitronix/btm[Bitronix] embedded transaction manager. +JTA transactions are also supported when deploying to a suitable Java EE Application Server. -When a JTA environment is detected, Spring's `JtaTransactionManager` is used to manage -transactions. Auto-configured JMS, DataSource, and JPA beans are upgraded to support XA -transactions. You can use standard Spring idioms, such as `@Transactional`, to participate -in a distributed transaction. If you are within a JTA environment and still want to use -local transactions, you can set the `spring.jta.enabled` property to `false` to disable -the JTA auto-configuration. +When a JTA environment is detected, Spring's `JtaTransactionManager` is used to manage transactions. +Auto-configured JMS, DataSource, and JPA beans are upgraded to support XA transactions. +You can use standard Spring idioms, such as `@Transactional`, to participate in a distributed transaction. +If you are within a JTA environment and still want to use local transactions, you can set the `spring.jta.enabled` property to `false` to disable the JTA auto-configuration. [[boot-features-jta-atomikos]] === Using an Atomikos Transaction Manager -https://www.atomikos.com/[Atomikos] is a popular open source transaction manager which can -be embedded into your Spring Boot application. You can use the -`spring-boot-starter-jta-atomikos` Starter to pull in the appropriate Atomikos libraries. -Spring Boot auto-configures Atomikos and ensures that appropriate `depends-on` settings -are applied to your Spring beans for correct startup and shutdown ordering. +https://www.atomikos.com/[Atomikos] is a popular open source transaction manager which can be embedded into your Spring Boot application. +You can use the `spring-boot-starter-jta-atomikos` starter to pull in the appropriate Atomikos libraries. +Spring Boot auto-configures Atomikos and ensures that appropriate `depends-on` settings are applied to your Spring beans for correct startup and shutdown ordering. -By default, Atomikos transaction logs are written to a `transaction-logs` directory in -your application's home directory (the directory in which your application jar file -resides). You can customize the location of this directory by setting a -`spring.jta.log-dir` property in your `application.properties` file. Properties starting -with `spring.jta.atomikos.properties` can also be used to customize the Atomikos -`UserTransactionServiceImp`. See the -{dc-spring-boot}/jta/atomikos/AtomikosProperties.{dc-ext}[`AtomikosProperties` Javadoc] -for complete details. +By default, Atomikos transaction logs are written to a `transaction-logs` directory in your application's home directory (the directory in which your application jar file resides). +You can customize the location of this directory by setting a `spring.jta.log-dir` property in your `application.properties` file. +Properties starting with `spring.jta.atomikos.properties` can also be used to customize the Atomikos `UserTransactionServiceImp`. +See the {dc-spring-boot}/jta/atomikos/AtomikosProperties.{dc-ext}[`AtomikosProperties` Javadoc] for complete details. -NOTE: To ensure that multiple transaction managers can safely coordinate the same -resource managers, each Atomikos instance must be configured with a unique ID. By default, -this ID is the IP address of the machine on which Atomikos is running. To ensure -uniqueness in production, you should configure the `spring.jta.transaction-manager-id` -property with a different value for each instance of your application. +NOTE: To ensure that multiple transaction managers can safely coordinate the same resource managers, each Atomikos instance must be configured with a unique ID. By default, this ID is the IP address of the machine on which Atomikos is running. +To ensure uniqueness in production, you should configure the `spring.jta.transaction-manager-id` property with a different value for each instance of your application. [[boot-features-jta-bitronix]] === Using a Bitronix Transaction Manager -https://github.com/bitronix/btm[Bitronix] is a popular open-source JTA transaction -manager implementation. You can use the `spring-boot-starter-jta-bitronix` starter to add -the appropriate Bitronix dependencies to your project. As with Atomikos, Spring Boot -automatically configures Bitronix and post-processes your beans to ensure that startup and -shutdown ordering is correct. +https://github.com/bitronix/btm[Bitronix] is a popular open-source JTA transaction manager implementation. +You can use the `spring-boot-starter-jta-bitronix` starter to add the appropriate Bitronix dependencies to your project. +As with Atomikos, Spring Boot automatically configures Bitronix and post-processes your beans to ensure that startup and shutdown ordering is correct. -By default, Bitronix transaction log files (`part1.btm` and `part2.btm`) are written to -a `transaction-logs` directory in your application home directory. You can customize the -location of this directory by setting the `spring.jta.log-dir` property. Properties -starting with `spring.jta.bitronix.properties` are also bound to the -`bitronix.tm.Configuration` bean, allowing for complete customization. See the -https://github.com/bitronix/btm/wiki/Transaction-manager-configuration[Bitronix -documentation] for details. +By default, Bitronix transaction log files (`part1.btm` and `part2.btm`) are written to a `transaction-logs` directory in your application home directory. +You can customize the location of this directory by setting the `spring.jta.log-dir` property. +Properties starting with `spring.jta.bitronix.properties` are also bound to the `bitronix.tm.Configuration` bean, allowing for complete customization. +See the https://github.com/bitronix/btm/wiki/Transaction-manager-configuration[Bitronix documentation] for details. -NOTE: To ensure that multiple transaction managers can safely coordinate the same -resource managers, each Bitronix instance must be configured with a unique ID. By default, -this ID is the IP address of the machine on which Bitronix is running. To ensure -uniqueness in production, you should configure the `spring.jta.transaction-manager-id` -property with a different value for each instance of your application. +NOTE: To ensure that multiple transaction managers can safely coordinate the same resource managers, each Bitronix instance must be configured with a unique ID. +By default, this ID is the IP address of the machine on which Bitronix is running. +To ensure uniqueness in production, you should configure the `spring.jta.transaction-manager-id` property with a different value for each instance of your application. [[boot-features-jta-javaee]] === Using a Java EE Managed Transaction Manager -If you package your Spring Boot application as a `war` or `ear` file and deploy it to a -Java EE application server, you can use your application server's built-in transaction -manager. Spring Boot tries to auto-configure a transaction manager by looking at common -JNDI locations (`java:comp/UserTransaction`, `java:comp/TransactionManager`, and so on). -If you use a transaction service provided by your application server, you generally also -want to ensure that all resources are managed by the server and exposed over JNDI. Spring -Boot tries to auto-configure JMS by looking for a `ConnectionFactory` at the JNDI path -(`java:/JmsXA` or `java:/XAConnectionFactory`), and you can use the -<> -to configure your `DataSource`. +If you package your Spring Boot application as a `war` or `ear` file and deploy it to a Java EE application server, you can use your application server's built-in transaction manager. +Spring Boot tries to auto-configure a transaction manager by looking at common JNDI locations (`java:comp/UserTransaction`, `java:comp/TransactionManager`, and so on). +If you use a transaction service provided by your application server, you generally also want to ensure that all resources are managed by the server and exposed over JNDI. +Spring Boot tries to auto-configure JMS by looking for a `ConnectionFactory` at the JNDI path (`java:/JmsXA` or `java:/XAConnectionFactory`), and you can use the <> to configure your `DataSource`. [[boot-features-jta-mixed-jms]] === Mixing XA and Non-XA JMS Connections -When using JTA, the primary JMS `ConnectionFactory` bean is XA-aware and participates -in distributed transactions. In some situations, you might want to process certain JMS -messages by using a non-XA `ConnectionFactory`. For example, your JMS processing logic -might take longer than the XA timeout. +When using JTA, the primary JMS `ConnectionFactory` bean is XA-aware and participates in distributed transactions. +In some situations, you might want to process certain JMS messages by using a non-XA `ConnectionFactory`. +For example, your JMS processing logic might take longer than the XA timeout. -If you want to use a non-XA `ConnectionFactory`, you can inject the -`nonXaJmsConnectionFactory` bean rather than the `@Primary` `jmsConnectionFactory` bean. -For consistency, the `jmsConnectionFactory` bean is also provided by using the bean alias -`xaJmsConnectionFactory`. +If you want to use a non-XA `ConnectionFactory`, you can inject the `nonXaJmsConnectionFactory` bean rather than the `@Primary` `jmsConnectionFactory` bean. +For consistency, the `jmsConnectionFactory` bean is also provided by using the bean alias `xaJmsConnectionFactory`. The following example shows how to inject `ConnectionFactory` instances: @@ -6269,119 +5250,88 @@ The following example shows how to inject `ConnectionFactory` instances: [[boot-features-jta-supporting-alternative-embedded]] === Supporting an Alternative Embedded Transaction Manager -The {sc-spring-boot}/jms/XAConnectionFactoryWrapper.{sc-ext}[`XAConnectionFactoryWrapper`] -and {sc-spring-boot}/jdbc/XADataSourceWrapper.{sc-ext}[`XADataSourceWrapper`] interfaces -can be used to support alternative embedded transaction managers. The interfaces are -responsible for wrapping `XAConnectionFactory` and `XADataSource` beans and exposing them -as regular `ConnectionFactory` and `DataSource` beans, which transparently enroll in the -distributed transaction. DataSource and JMS auto-configuration use JTA variants, provided -you have a `JtaTransactionManager` bean and appropriate XA wrapper beans registered -within your `ApplicationContext`. +The {sc-spring-boot}/jms/XAConnectionFactoryWrapper.{sc-ext}[`XAConnectionFactoryWrapper`] and {sc-spring-boot}/jdbc/XADataSourceWrapper.{sc-ext}[`XADataSourceWrapper`] interfaces can be used to support alternative embedded transaction managers. +The interfaces are responsible for wrapping `XAConnectionFactory` and `XADataSource` beans and exposing them as regular `ConnectionFactory` and `DataSource` beans, which transparently enroll in the distributed transaction. +DataSource and JMS auto-configuration use JTA variants, provided you have a `JtaTransactionManager` bean and appropriate XA wrapper beans registered within your `ApplicationContext`. -The {sc-spring-boot}/jta/bitronix/BitronixXAConnectionFactoryWrapper.{sc-ext}[BitronixXAConnectionFactoryWrapper] -and {sc-spring-boot}/jta/bitronix/BitronixXADataSourceWrapper.{sc-ext}[BitronixXADataSourceWrapper] -provide good examples of how to write XA wrappers. +The {sc-spring-boot}/jta/bitronix/BitronixXAConnectionFactoryWrapper.{sc-ext}[BitronixXAConnectionFactoryWrapper] and {sc-spring-boot}/jta/bitronix/BitronixXADataSourceWrapper.{sc-ext}[BitronixXADataSourceWrapper] provide good examples of how to write XA wrappers. [[boot-features-hazelcast]] == Hazelcast +If https://hazelcast.com/[Hazelcast] is on the classpath and a suitable configuration is found, Spring Boot auto-configures a `HazelcastInstance` that you can inject in your application. -If https://hazelcast.com/[Hazelcast] is on the classpath and a suitable configuration is -found, Spring Boot auto-configures a `HazelcastInstance` that you can inject in your -application. +If you define a `com.hazelcast.config.Config` bean, Spring Boot uses that. +If your configuration defines an instance name, Spring Boot tries to locate an existing instance rather than creating a new one. -If you define a `com.hazelcast.config.Config` bean, Spring Boot uses that. If your -configuration defines an instance name, Spring Boot tries to locate an existing instance -rather than creating a new one. - -You could also specify the `hazelcast.xml` configuration file to use through -configuration, as shown in the following example: +You could also specify the `hazelcast.xml` configuration file to use through configuration, as shown in the following example: [source,properties,indent=0] ---- spring.hazelcast.config=classpath:config/my-hazelcast.xml ---- -Otherwise, Spring Boot tries to find the Hazelcast configuration from the default -locations: `hazelcast.xml` in the working directory or at the root of the classpath. We -also check if the `hazelcast.config` system property is set. See the -https://docs.hazelcast.org/docs/latest/manual/html-single/[Hazelcast documentation] for -more details. +Otherwise, Spring Boot tries to find the Hazelcast configuration from the default locations: `hazelcast.xml` in the working directory or at the root of the classpath. +We also check if the `hazelcast.config` system property is set. +See the https://docs.hazelcast.org/docs/latest/manual/html-single/[Hazelcast documentation] for more details. -If `hazelcast-client` is present on the classpath, Spring Boot first attempts to create a -client by checking the following configuration options: +If `hazelcast-client` is present on the classpath, Spring Boot first attempts to create a client by checking the following configuration options: * The presence of a `com.hazelcast.client.config.ClientConfig` bean. * A configuration file defined by the `spring.hazelcast.config` property. * The presence of the `hazelcast.client.config` system property. * A `hazelcast-client.xml` in the working directory or at the root of the classpath. -NOTE: Spring Boot also has -<>. If -caching is enabled, the `HazelcastInstance` is automatically wrapped in a `CacheManager` -implementation. +NOTE: Spring Boot also has <>. +If caching is enabled, the `HazelcastInstance` is automatically wrapped in a `CacheManager` implementation. [[boot-features-quartz]] == Quartz Scheduler -Spring Boot offers several conveniences for working with the -https://www.quartz-scheduler.org/[Quartz scheduler], including the -`spring-boot-starter-quartz` "`Starter`". If Quartz is available, a `Scheduler` is -auto-configured (through the `SchedulerFactoryBean` abstraction). +Spring Boot offers several conveniences for working with the https://www.quartz-scheduler.org/[Quartz scheduler], including the `spring-boot-starter-quartz` "`Starter`". +If Quartz is available, a `Scheduler` is auto-configured (through the `SchedulerFactoryBean` abstraction). -Beans of the following types are automatically picked up and associated with the -`Scheduler`: +Beans of the following types are automatically picked up and associated with the `Scheduler`: -* `JobDetail`: defines a particular Job. `JobDetail` instances can be built with the -`JobBuilder` API. +* `JobDetail`: defines a particular Job. `JobDetail` instances can be built with the `JobBuilder` API. * `Calendar`. * `Trigger`: defines when a particular job is triggered. -By default, an in-memory `JobStore` is used. However, it is possible to configure a -JDBC-based store if a `DataSource` bean is available in your application and if the -`spring.quartz.job-store-type` property is configured accordingly, as shown in the -following example: +By default, an in-memory `JobStore` is used. +However, it is possible to configure a JDBC-based store if a `DataSource` bean is available in your application and if the `spring.quartz.job-store-type` property is configured accordingly, as shown in the following example: [source,properties,indent=0] ---- spring.quartz.job-store-type=jdbc ---- -When the JDBC store is used, the schema can be initialized on startup, as shown in the -following example: +When the JDBC store is used, the schema can be initialized on startup, as shown in the following example: [source,properties,indent=0] ---- spring.quartz.jdbc.initialize-schema=always ---- -WARNING: By default, the database is detected and initialized by using the standard scripts -provided with the Quartz library. These scripts drop existing tables, deleting all triggers -on every restart. It is also possible to provide a custom script by setting the -`spring.quartz.jdbc.schema` property. +WARNING: By default, the database is detected and initialized by using the standard scripts provided with the Quartz library. +These scripts drop existing tables, deleting all triggers on every restart. +It is also possible to provide a custom script by setting the `spring.quartz.jdbc.schema` property. -To have Quartz use a `DataSource` other than the application's main `DataSource`, declare -a `DataSource` bean, annotating its `@Bean` method with `@QuartzDataSource`. Doing so -ensures that the Quartz-specific `DataSource` is used by both the `SchedulerFactoryBean` -and for schema initialization. +To have Quartz use a `DataSource` other than the application's main `DataSource`, declare a `DataSource` bean, annotating its `@Bean` method with `@QuartzDataSource`. +Doing so ensures that the Quartz-specific `DataSource` is used by both the `SchedulerFactoryBean` and for schema initialization. -By default, jobs created by configuration will not overwrite already registered jobs that -have been read from a persistent job store. To enable overwriting existing job definitions -set the `spring.quartz.overwrite-existing-jobs` property. +By default, jobs created by configuration will not overwrite already registered jobs that have been read from a persistent job store. +To enable overwriting existing job definitions set the `spring.quartz.overwrite-existing-jobs` property. -Quartz Scheduler configuration can be customized using `spring.quartz` properties and -`SchedulerFactoryBeanCustomizer` beans, which allow programmatic `SchedulerFactoryBean` -customization. Advanced Quartz configuration properties can be customized using -`spring.quartz.properties.*`. +Quartz Scheduler configuration can be customized using `spring.quartz` properties and `SchedulerFactoryBeanCustomizer` beans, which allow programmatic `SchedulerFactoryBean` customization. +Advanced Quartz configuration properties can be customized using `spring.quartz.properties.*`. -NOTE: In particular, an `Executor` bean is not associated with the scheduler as Quartz -offers a way to configure the scheduler via `spring.quartz.properties`. If you need -to customize the task executor, consider implementing `SchedulerFactoryBeanCustomizer`. +NOTE: In particular, an `Executor` bean is not associated with the scheduler as Quartz offers a way to configure the scheduler via `spring.quartz.properties`. +If you need to customize the task executor, consider implementing `SchedulerFactoryBeanCustomizer`. -Jobs can define setters to inject data map properties. Regular beans can also be injected -in a similar manner, as shown in the following example: +Jobs can define setters to inject data map properties. +Regular beans can also be injected in a similar manner, as shown in the following example: [source,java,indent=0] ---- @@ -6410,27 +5360,18 @@ in a similar manner, as shown in the following example: [[boot-features-task-execution-scheduling]] == Task Execution and Scheduling -In the absence of an `Executor` bean in the context, Spring Boot auto-configures a -`ThreadPoolTaskExecutor` with sensible defaults that can be automatically associated to -asynchronous task execution (`@EnableAsync`) and Spring MVC asynchronous request -processing. +In the absence of an `Executor` bean in the context, Spring Boot auto-configures a `ThreadPoolTaskExecutor` with sensible defaults that can be automatically associated to asynchronous task execution (`@EnableAsync`) and Spring MVC asynchronous request processing. [TIP] ==== -If you have defined a custom `Executor` in the context, regular task execution (i.e. -`@EnableAsync`) will use it transparently but the Spring MVC support will not be -configured as it requires an `AsyncTaskExecutor` implementation (named -`applicationTaskExecutor`). Depending on your target arrangement, you could change your -`Executor` into a `ThreadPoolTaskExecutor` or define both a `ThreadPoolTaskExecutor` and -an `AsyncConfigurer` wrapping your custom `Executor`. +If you have defined a custom `Executor` in the context, regular task execution (i.e. `@EnableAsync`) will use it transparently but the Spring MVC support will not be configured as it requires an `AsyncTaskExecutor` implementation (named `applicationTaskExecutor`). +Depending on your target arrangement, you could change your `Executor` into a `ThreadPoolTaskExecutor` or define both a `ThreadPoolTaskExecutor` and an `AsyncConfigurer` wrapping your custom `Executor`. -The auto-configured `TaskExecutorBuilder` allows you to easily create instances that -reproduce what the auto-configuration does by default. +The auto-configured `TaskExecutorBuilder` allows you to easily create instances that reproduce what the auto-configuration does by default. ==== -The thread pool uses 8 core threads that can grow and shrink according to the load. Those -default settings can be fine-tuned using the `spring.task.execution` namespace as shown in -the following example: +The thread pool uses 8 core threads that can grow and shrink according to the load. +Those default settings can be fine-tuned using the `spring.task.execution` namespace as shown in the following example: [source,properties,indent=0] ---- @@ -6439,55 +5380,42 @@ the following example: spring.task.execution.pool.keep-alive=10s ---- -This changes the thread pool to use a bounded queue so that when the queue is full (100 -tasks), the thread pool increases to maximum 16 threads. Shrinking of the pool is more -aggressive as threads are reclaimed when they are idle for 10 seconds (rather than -60 seconds by default). +This changes the thread pool to use a bounded queue so that when the queue is full (100 tasks), the thread pool increases to maximum 16 threads. +Shrinking of the pool is more aggressive as threads are reclaimed when they are idle for 10 seconds (rather than 60 seconds by default). -A `ThreadPoolTaskScheduler` can also be auto-configured if need to be associated to -scheduled task execution (`@EnableScheduling`). The thread pool uses one thread by default -and those settings can be fine-tuned using the `spring.task.scheduling` namespace. +A `ThreadPoolTaskScheduler` can also be auto-configured if need to be associated to scheduled task execution (`@EnableScheduling`). +The thread pool uses one thread by default and those settings can be fine-tuned using the `spring.task.scheduling` namespace. -Both a `TaskExecutorBuilder` bean and a `TaskSchedulerBuilder` bean are made available in -the context if a custom executor or scheduler needs to be created. +Both a `TaskExecutorBuilder` bean and a `TaskSchedulerBuilder` bean are made available in the context if a custom executor or scheduler needs to be created. [[boot-features-integration]] == Spring Integration -Spring Boot offers several conveniences for working with {spring-integration}[Spring -Integration], including the `spring-boot-starter-integration` "`Starter`". Spring -Integration provides abstractions over messaging and also other transports such as HTTP, -TCP, and others. If Spring Integration is available on your classpath, it is initialized -through the `@EnableIntegration` annotation. +Spring Boot offers several conveniences for working with {spring-integration}[Spring Integration], including the `spring-boot-starter-integration` "`Starter`". +Spring Integration provides abstractions over messaging and also other transports such as HTTP, TCP, and others. +If Spring Integration is available on your classpath, it is initialized through the `@EnableIntegration` annotation. -Spring Boot also configures some features that are triggered by the presence of additional -Spring Integration modules. If `spring-integration-jmx` is also on the classpath, -message processing statistics are published over JMX . If `spring-integration-jdbc` is -available, the default database schema can be created on startup, as shown in the -following line: +Spring Boot also configures some features that are triggered by the presence of additional Spring Integration modules. +If `spring-integration-jmx` is also on the classpath, message processing statistics are published over JMX. +If `spring-integration-jdbc` is available, the default database schema can be created on startup, as shown in the following line: [source,properties,indent=0] ---- spring.integration.jdbc.initialize-schema=always ---- -See the -{sc-spring-boot-autoconfigure}/integration/IntegrationAutoConfiguration.{sc-ext}[`IntegrationAutoConfiguration`] -and {sc-spring-boot-autoconfigure}/integration/IntegrationProperties.{sc-ext}[`IntegrationProperties`] -classes for more details. +See the {sc-spring-boot-autoconfigure}/integration/IntegrationAutoConfiguration.{sc-ext}[`IntegrationAutoConfiguration`] and {sc-spring-boot-autoconfigure}/integration/IntegrationProperties.{sc-ext}[`IntegrationProperties`] classes for more details. -By default, if a Micrometer `meterRegistry` bean is present, Spring Integration metrics -will be managed by Micrometer. If you wish to use legacy Spring Integration metrics, add -a `DefaultMetricsFactory` bean to the application context. +By default, if a Micrometer `meterRegistry` bean is present, Spring Integration metrics will be managed by Micrometer. +If you wish to use legacy Spring Integration metrics, add a `DefaultMetricsFactory` bean to the application context. [[boot-features-session]] == Spring Session -Spring Boot provides {spring-session}[Spring Session] auto-configuration for a wide range -of data stores. When building a Servlet web application, the following stores can be -auto-configured: +Spring Boot provides {spring-session}[Spring Session] auto-configuration for a wide range of data stores. +When building a Servlet web application, the following stores can be auto-configured: * JDBC * Redis @@ -6499,11 +5427,9 @@ When building a reactive web application, the following stores can be auto-confi * Redis * MongoDB -If a single Spring Session module is present on the classpath, Spring Boot uses that store -implementation automatically. If you have more than one implementation, you must choose -the {sc-spring-boot-autoconfigure}/session/StoreType.{sc-ext}[`StoreType`] that you wish -to use to store the sessions. For instance, to use JDBC as the back-end store, you can -configure your application as follows: +If a single Spring Session module is present on the classpath, Spring Boot uses that store implementation automatically. +If you have more than one implementation, you must choose the {sc-spring-boot-autoconfigure}/session/StoreType.{sc-ext}[`StoreType`] that you wish to use to store the sessions. +For instance, to use JDBC as the back-end store, you can configure your application as follows: [source,properties,indent=0] ---- @@ -6512,8 +5438,8 @@ configure your application as follows: TIP: You can disable Spring Session by setting the `store-type` to `none`. -Each store has specific additional settings. For instance, it is possible to customize -the name of the table for the JDBC store, as shown in the following example: +Each store has specific additional settings. +For instance, it is possible to customize the name of the table for the JDBC store, as shown in the following example: [source,properties,indent=0] ---- @@ -6521,140 +5447,106 @@ the name of the table for the JDBC store, as shown in the following example: ---- For setting the timeout of the session you can use the `spring.session.timeout` property. -If that property is not set, the auto-configuration falls back to the value of -`server.servlet.session.timeout`. +If that property is not set, the auto-configuration falls back to the value of `server.servlet.session.timeout`. + + [[boot-features-jmx]] == Monitoring and Management over JMX -Java Management Extensions (JMX) provide a standard mechanism to monitor and manage -applications. Spring Boot exposes the most suitable `MBeanServer` as a bean with an ID of -`mbeanServer`. Any of your beans that are annotated with Spring JMX annotations ( -`@ManagedResource`, `@ManagedAttribute`, or `@ManagedOperation`) are exposed to it. +Java Management Extensions (JMX) provide a standard mechanism to monitor and manage applications. +Spring Boot exposes the most suitable `MBeanServer` as a bean with an ID of `mbeanServer`. +Any of your beans that are annotated with Spring JMX annotations (`@ManagedResource`, `@ManagedAttribute`, or `@ManagedOperation`) are exposed to it. -If your platform provides a standard `MBeanServer`, Spring Boot will use that and default -to the VM `MBeanServer` if necessary. If all that fails, a new `MBeanServer` will be -created. +If your platform provides a standard `MBeanServer`, Spring Boot will use that and default to the VM `MBeanServer` if necessary. +If all that fails, a new `MBeanServer` will be created. -See the -{sc-spring-boot-autoconfigure}/jmx/JmxAutoConfiguration.{sc-ext}[`JmxAutoConfiguration`] -class for more details. +See the {sc-spring-boot-autoconfigure}/jmx/JmxAutoConfiguration.{sc-ext}[`JmxAutoConfiguration`] class for more details. [[boot-features-testing]] == Testing -Spring Boot provides a number of utilities and annotations to help when testing your -application. Test support is provided by two modules: `spring-boot-test` contains core -items, and `spring-boot-test-autoconfigure` supports auto-configuration for tests. +Spring Boot provides a number of utilities and annotations to help when testing your application. +Test support is provided by two modules: `spring-boot-test` contains core items, and `spring-boot-test-autoconfigure` supports auto-configuration for tests. -Most developers use the `spring-boot-starter-test` "`Starter`", which imports both Spring -Boot test modules as well as JUnit, AssertJ, Hamcrest, and a number of other useful -libraries. +Most developers use the `spring-boot-starter-test` "`Starter`", which imports both Spring Boot test modules as well as JUnit, AssertJ, Hamcrest, and a number of other useful libraries. [[boot-features-test-scope-dependencies]] === Test Scope Dependencies -The `spring-boot-starter-test` "`Starter`" (in the `test` `scope`) contains -the following provided libraries: +The `spring-boot-starter-test` "`Starter`" (in the `test` `scope`) contains the following provided libraries: * https://junit.org[JUnit 4]: The de-facto standard for unit testing Java applications. -* {spring-reference}testing.html#integration-testing[Spring Test] & Spring Boot Test: -Utilities and integration test support for Spring Boot applications. +* {spring-reference}testing.html#integration-testing[Spring Test] & Spring Boot Test: Utilities and integration test support for Spring Boot applications. * https://joel-costigliola.github.io/assertj/[AssertJ]: A fluent assertion library. -* https://github.com/hamcrest/JavaHamcrest[Hamcrest]: A library of matcher objects (also -known as constraints or predicates). +* https://github.com/hamcrest/JavaHamcrest[Hamcrest]: A library of matcher objects (also known as constraints or predicates). * https://mockito.github.io[Mockito]: A Java mocking framework. * https://github.com/skyscreamer/JSONassert[JSONassert]: An assertion library for JSON. * https://github.com/jayway/JsonPath[JsonPath]: XPath for JSON. -We generally find these common libraries to be useful when writing tests. If these -libraries do not suit your needs, you can add additional test dependencies of your own. +We generally find these common libraries to be useful when writing tests. +If these libraries do not suit your needs, you can add additional test dependencies of your own. [[boot-features-testing-spring-applications]] === Testing Spring Applications -One of the major advantages of dependency injection is that it should make your code -easier to unit test. You can instantiate objects by using the `new` operator without -even involving Spring. You can also use _mock objects_ instead of real dependencies. +One of the major advantages of dependency injection is that it should make your code easier to unit test. +You can instantiate objects by using the `new` operator without even involving Spring. +You can also use _mock objects_ instead of real dependencies. -Often, you need to move beyond unit testing and start integration testing (with -a Spring `ApplicationContext`). It is useful to be able to perform integration testing -without requiring deployment of your application or needing to connect to other -infrastructure. +Often, you need to move beyond unit testing and start integration testing (with a Spring `ApplicationContext`). +It is useful to be able to perform integration testing without requiring deployment of your application or needing to connect to other infrastructure. -The Spring Framework includes a dedicated test module for such integration testing. You -can declare a dependency directly to `org.springframework:spring-test` or use the -`spring-boot-starter-test` "`Starter`" to pull it in transitively. +The Spring Framework includes a dedicated test module for such integration testing. +You can declare a dependency directly to `org.springframework:spring-test` or use the `spring-boot-starter-test` "`Starter`" to pull it in transitively. -If you have not used the `spring-test` module before, you should start by reading the -{spring-reference}testing.html#testing[relevant section] of the Spring Framework -reference documentation. +If you have not used the `spring-test` module before, you should start by reading the {spring-reference}testing.html#testing[relevant section] of the Spring Framework reference documentation. [[boot-features-testing-spring-boot-applications]] === Testing Spring Boot Applications -A Spring Boot application is a Spring `ApplicationContext`, so nothing very special has -to be done to test it beyond what you would normally do with a vanilla Spring context. +A Spring Boot application is a Spring `ApplicationContext`, so nothing very special has to be done to test it beyond what you would normally do with a vanilla Spring context. -NOTE: External properties, logging, and other features of Spring Boot are installed in the -context by default only if you use `SpringApplication` to create it. +NOTE: External properties, logging, and other features of Spring Boot are installed in the context by default only if you use `SpringApplication` to create it. -Spring Boot provides a `@SpringBootTest` annotation, which can be used as an alternative -to the standard `spring-test` `@ContextConfiguration` annotation when you need Spring -Boot features. The annotation works by -<>. In addition to -`@SpringBootTest` a number of other annotations are also provided for -<> of an application. +Spring Boot provides a `@SpringBootTest` annotation, which can be used as an alternative to the standard `spring-test` `@ContextConfiguration` annotation when you need Spring Boot features. +The annotation works by <>. +In addition to `@SpringBootTest` a number of other annotations are also provided for <> of an application. -TIP: If you are using JUnit 4, don't forget to also add `@RunWith(SpringRunner.class)` to -your test, otherwise the annotations will be ignored. If you are using JUnit 5, there's no -need to add the equivalent `@ExtendWith(SpringExtension.class)` as `@SpringBootTest` and -the other `@…Test` annotations are already annotated with it. +TIP: If you are using JUnit 4, don't forget to also add `@RunWith(SpringRunner.class)` to your test, otherwise the annotations will be ignored. +If you are using JUnit 5, there's no need to add the equivalent `@ExtendWith(SpringExtension.class)` as `@SpringBootTest` and the other `@…Test` annotations are already annotated with it. -By default, `@SpringBootTest` will not start a server. You can use the `webEnvironment` -attribute of `@SpringBootTest` to further refine how your tests run: +By default, `@SpringBootTest` will not start a server. +You can use the `webEnvironment` attribute of `@SpringBootTest` to further refine how your tests run: -* `MOCK`(Default) : Loads a web `ApplicationContext` and provides a mock web -environment. Embedded servers are not started when using this annotation. If a web -environment is not available on your classpath, this mode transparently falls back to -creating a regular non-web `ApplicationContext`. It can be used in conjunction with -<> for mock-based testing of your -web application. -* `RANDOM_PORT`: Loads a `WebServerApplicationContext` and provides a real web -environment. Embedded servers are started and listen on a random port. -* `DEFINED_PORT`: Loads a `WebServerApplicationContext` and provides a real web -environment. Embedded servers are started and listen on a defined port (from your -`application.properties`) or on the default port of `8080`. -* `NONE`: Loads an `ApplicationContext` by using `SpringApplication` but does not provide -_any_ web environment (mock or otherwise). +* `MOCK`(Default) : Loads a web `ApplicationContext` and provides a mock web environment. +Embedded servers are not started when using this annotation. +If a web environment is not available on your classpath, this mode transparently falls back to creating a regular non-web `ApplicationContext`. +It can be used in conjunction with <> for mock-based testing of your web application. +* `RANDOM_PORT`: Loads a `WebServerApplicationContext` and provides a real web environment. +Embedded servers are started and listen on a random port. +* `DEFINED_PORT`: Loads a `WebServerApplicationContext` and provides a real web environment. +Embedded servers are started and listen on a defined port (from your `application.properties`) or on the default port of `8080`. +* `NONE`: Loads an `ApplicationContext` by using `SpringApplication` but does not provide _any_ web environment (mock or otherwise). -NOTE: If your test is `@Transactional`, it rolls back the transaction at the end of each -test method by default. However, as using this arrangement with either `RANDOM_PORT` or -`DEFINED_PORT` implicitly provides a real servlet environment, the HTTP client and server -run in separate threads and, thus, in separate transactions. Any transaction initiated on -the server does not roll back in this case. +NOTE: If your test is `@Transactional`, it rolls back the transaction at the end of each test method by default. +However, as using this arrangement with either `RANDOM_PORT` or `DEFINED_PORT` implicitly provides a real servlet environment, the HTTP client and server run in separate threads and, thus, in separate transactions. +Any transaction initiated on the server does not roll back in this case. -NOTE: `@SpringBootTest` with `webEnvironment = WebEnvironment.RANDOM_PORT` will also -start the management server on a separate random port if your application uses a different -port for the management server. +NOTE: `@SpringBootTest` with `webEnvironment = WebEnvironment.RANDOM_PORT` will also start the management server on a separate random port if your application uses a different port for the management server. [[boot-features-testing-spring-boot-applications-detecting-web-app-type]] ==== Detecting Web Application Type -If Spring MVC is available, a regular MVC-based application context is configured. If you -have only Spring WebFlux, we'll detect that and configure a WebFlux-based application -context instead. +If Spring MVC is available, a regular MVC-based application context is configured. +If you have only Spring WebFlux, we'll detect that and configure a WebFlux-based application context instead. -If both are present, Spring MVC takes precedence. If you want to test a reactive web -application in this scenario, you must set the `spring.main.web-application-type` -property: +If both are present, Spring MVC takes precedence. +If you want to test a reactive web application in this scenario, you must set the `spring.main.web-application-type` property: [source,java,indent=0] ---- @@ -6667,57 +5559,39 @@ property: [[boot-features-testing-spring-boot-applications-detecting-config]] ==== Detecting Test Configuration -If you are familiar with the Spring Test Framework, you may be used to using -`@ContextConfiguration(classes=...)` in order to specify which Spring `@Configuration` to -load. Alternatively, you might have often used nested `@Configuration` classes within -your test. +If you are familiar with the Spring Test Framework, you may be used to using `@ContextConfiguration(classes=...)` in order to specify which Spring `@Configuration` to load. +Alternatively, you might have often used nested `@Configuration` classes within your test. -When testing Spring Boot applications, this is often not required. Spring Boot's `@*Test` -annotations search for your primary configuration automatically whenever you do not -explicitly define one. +When testing Spring Boot applications, this is often not required. +Spring Boot's `@*Test` annotations search for your primary configuration automatically whenever you do not explicitly define one. -The search algorithm works up from the package that contains the test until it finds a -class annotated with `@SpringBootApplication` or `@SpringBootConfiguration`. As long as -you <> in a sensible way, your -main configuration is usually found. +The search algorithm works up from the package that contains the test until it finds a class annotated with `@SpringBootApplication` or `@SpringBootConfiguration`. +As long as you <> in a sensible way, your main configuration is usually found. [NOTE] ==== -If you use a -<>, you should avoid adding -configuration settings that are specific to a particular area on the -<>. +If you use a <>, you should avoid adding configuration settings that are specific to a particular area on the <>. -The underlying component scan configuration of `@SpringBootApplication` defines exclude -filters that are used to make sure slicing works as expected. If you are using an explicit -`@ComponentScan` directive on your `@SpringBootApplication`-annotated class, be aware that -those filters will be disabled. If you are using slicing, you should define them again. +The underlying component scan configuration of `@SpringBootApplication` defines exclude filters that are used to make sure slicing works as expected. +If you are using an explicit `@ComponentScan` directive on your `@SpringBootApplication`-annotated class, be aware that those filters will be disabled. +If you are using slicing, you should define them again. ==== -If you want to customize the primary configuration, you can use a nested -`@TestConfiguration` class. Unlike a nested `@Configuration` class, which would be used -instead of your application's primary configuration, a nested `@TestConfiguration` class -is used in addition to your application's primary configuration. +If you want to customize the primary configuration, you can use a nested `@TestConfiguration` class. +Unlike a nested `@Configuration` class, which would be used instead of your application's primary configuration, a nested `@TestConfiguration` class is used in addition to your application's primary configuration. -NOTE: Spring's test framework caches application contexts between tests. Therefore, as -long as your tests share the same configuration (no matter how it is discovered), the -potentially time-consuming process of loading the context happens only once. +NOTE: Spring's test framework caches application contexts between tests. +Therefore, as long as your tests share the same configuration (no matter how it is discovered), the potentially time-consuming process of loading the context happens only once. [[boot-features-testing-spring-boot-applications-excluding-config]] ==== Excluding Test Configuration -If your application uses component scanning (for example, if you use -`@SpringBootApplication` or `@ComponentScan`), you may find top-level configuration -classes that you created only for specific tests accidentally get picked up everywhere. +If your application uses component scanning (for example, if you use `@SpringBootApplication` or `@ComponentScan`), you may find top-level configuration classes that you created only for specific tests accidentally get picked up everywhere. -As we <>, `@TestConfiguration` can be used on an inner class of a test to customize the -primary configuration. When placed on a top-level class, `@TestConfiguration` indicates -that classes in `src/test/java` should not be picked up by scanning. You can then import -that class explicitly where it is required, as shown in the following example: +As we <>, `@TestConfiguration` can be used on an inner class of a test to customize the primary configuration. +When placed on a top-level class, `@TestConfiguration` indicates that classes in `src/test/java` should not be picked up by scanning. +You can then import that class explicitly where it is required, as shown in the following example: [source,java,indent=0] ---- @@ -6734,31 +5608,24 @@ that class explicitly where it is required, as shown in the following example: } ---- -NOTE: If you directly use `@ComponentScan` (that is, not through -`@SpringBootApplication`) you need to register the `TypeExcludeFilter` with it. See -{dc-spring-boot}/context/TypeExcludeFilter.{dc-ext}[the Javadoc] for details. +NOTE: If you directly use `@ComponentScan` (that is, not through `@SpringBootApplication`) you need to register the `TypeExcludeFilter` with it. +See {dc-spring-boot}/context/TypeExcludeFilter.{dc-ext}[the Javadoc] for details. + [[boot-features-testing-spring-boot-applications-testing-with-mock-environment]] ==== Testing with a mock environment -By default, `@SpringBootTest` does not start the server. If you have web endpoints that -you want to test against this mock environment, you can additionally configure -{spring-reference}/testing.html#spring-mvc-test-framework[`MockMvc`] as shown in the -following example: +By default, `@SpringBootTest` does not start the server. +If you have web endpoints that you want to test against this mock environment, you can additionally configure {spring-reference}/testing.html#spring-mvc-test-framework[`MockMvc`] as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/test/web/MockMvcExampleTests.java[tag=test-mock-mvc] ---- -TIP: If you want to focus only on the web layer and not start a complete -`ApplicationContext`, consider -<>. +TIP: If you want to focus only on the web layer and not start a complete `ApplicationContext`, consider <>. -Alternatively, you can configure a -{spring-reference}testing.html#webtestclient-tests[`WebTestClient`] as shown in the -following example: +Alternatively, you can configure a {spring-reference}testing.html#webtestclient-tests[`WebTestClient`] as shown in the following example: [source,java,indent=0] ---- @@ -6770,24 +5637,18 @@ include::{code-examples}/test/web/MockWebTestClientExampleTests.java[tag=test-mo [[boot-features-testing-spring-boot-applications-testing-with-running-server]] ==== Testing with a running server If you need to start a full running server, we recommend that you use random ports. -If you use `@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)`, an -available port is picked at random each time your test runs. +If you use `@SpringBootTest(webEnvironment=WebEnvironment.RANDOM_PORT)`, an available port is picked at random each time your test runs. -The `@LocalServerPort` annotation can be used to -<> into your test. -For convenience, tests that need to make REST calls to the started server can -additionally `@Autowire` a -{spring-reference}testing.html#webtestclient-tests[`WebTestClient`], which resolves -relative links to the running server and comes with a dedicated API for verifying -responses, as shown in the following example: +The `@LocalServerPort` annotation can be used to <> into your test. +For convenience, tests that need to make REST calls to the started server can additionally `@Autowire` a {spring-reference}testing.html#webtestclient-tests[`WebTestClient`], which resolves relative links to the running server and comes with a dedicated API for verifying responses, as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/test/web/RandomPortWebTestClientExampleTests.java[tag=test-random-port] ---- -This setup requires `spring-webflux` on the classpath. If you can't or won't add webflux, -Spring Boot also provides a `TestRestTemplate` facility: +This setup requires `spring-webflux` on the classpath. +If you can't or won't add webflux, Spring Boot also provides a `TestRestTemplate` facility: [source,java,indent=0] ---- @@ -6798,9 +5659,8 @@ include::{code-examples}/test/web/RandomPortTestRestTemplateExampleTests.java[ta [[boot-features-testing-spring-boot-applications-jmx]] ==== Using JMX -As the test context framework caches context, JMX is disabled by default to prevent -identical components to register on the same domain. If such test needs access to an -`MBeanServer`, consider marking it dirty as well: +As the test context framework caches context, JMX is disabled by default to prevent identical components to register on the same domain. +If such test needs access to an `MBeanServer`, consider marking it dirty as well: [source,java,indent=0] ---- @@ -6811,23 +5671,20 @@ include::{test-examples}/jmx/SampleJmxTests.java[tag=test] [[boot-features-testing-spring-boot-applications-mocking-beans]] ==== Mocking and Spying Beans -When running tests, it is sometimes necessary to mock certain components within your -application context. For example, you may have a facade over some remote service that is -unavailable during development. Mocking can also be useful when you want to simulate -failures that might be hard to trigger in a real environment. +When running tests, it is sometimes necessary to mock certain components within your application context. +For example, you may have a facade over some remote service that is unavailable during development. +Mocking can also be useful when you want to simulate failures that might be hard to trigger in a real environment. -Spring Boot includes a `@MockBean` annotation that can be used to define a Mockito mock -for a bean inside your `ApplicationContext`. You can use the annotation to add new beans -or replace a single existing bean definition. The annotation can be used directly on test -classes, on fields within your test, or on `@Configuration` classes and fields. When used -on a field, the instance of the created mock is also injected. Mock beans are -automatically reset after each test method. +Spring Boot includes a `@MockBean` annotation that can be used to define a Mockito mock for a bean inside your `ApplicationContext`. +You can use the annotation to add new beans or replace a single existing bean definition. +The annotation can be used directly on test classes, on fields within your test, or on `@Configuration` classes and fields. +When used on a field, the instance of the created mock is also injected. +Mock beans are automatically reset after each test method. [NOTE] ==== -If your test uses one of Spring Boot's test annotations (such as `@SpringBootTest`), this -feature is automatically enabled. To use this feature with a different -arrangement, a listener must be explicitly added, as shown in the following example: +If your test uses one of Spring Boot's test annotations (such as `@SpringBootTest`), this feature is automatically enabled. +To use this feature with a different arrangement, a listener must be explicitly added, as shown in the following example: [source,java,indent=0] ---- @@ -6836,8 +5693,7 @@ arrangement, a listener must be explicitly added, as shown in the following exam ==== -The following example replaces an existing `RemoteService` bean with a mock -implementation: +The following example replaces an existing `RemoteService` bean with a mock implementation: [source,java,indent=0] ---- @@ -6872,76 +5728,58 @@ implementation: } ---- -NOTE: `@MockBean` cannot be used to mock the behavior of a bean that's exercised during -application context refresh. By the time the test is executed, the application context refresh -has completed and it is too late to configure the mocked behavior. We recommend using a `@Bean` -method to create and configure the mock in this situation. +NOTE: `@MockBean` cannot be used to mock the behavior of a bean that's exercised during application context refresh. +By the time the test is executed, the application context refresh has completed and it is too late to configure the mocked behavior. +We recommend using a `@Bean` method to create and configure the mock in this situation. -Additionally, you can use `@SpyBean` to wrap any existing bean with a Mockito `spy`. See -the {dc-spring-boot-test}/mock/mockito/SpyBean.{dc-ext}[Javadoc] for full details. +Additionally, you can use `@SpyBean` to wrap any existing bean with a Mockito `spy`. +See the {dc-spring-boot-test}/mock/mockito/SpyBean.{dc-ext}[Javadoc] for full details. -NOTE: While Spring's test framework caches application contexts between tests and reuses -a context for tests sharing the same configuration, the use of `@MockBean` or `@SpyBean` -influences the cache key, which will most likely increase the number of contexts. +NOTE: While Spring's test framework caches application contexts between tests and reuses a context for tests sharing the same configuration, the use of `@MockBean` or `@SpyBean` influences the cache key, which will most likely increase the number of contexts. -TIP: If you are using `@SpyBean` to spy on a bean with `@Cacheable` methods that refer -to parameters by name, your application must be compiled with `-parameters`. This -ensures that the parameter names are available to the caching infrastructure once the -bean has been spied upon. +TIP: If you are using `@SpyBean` to spy on a bean with `@Cacheable` methods that refer to parameters by name, your application must be compiled with `-parameters`. +This ensures that the parameter names are available to the caching infrastructure once the bean has been spied upon. [[boot-features-testing-spring-boot-applications-testing-autoconfigured-tests]] ==== Auto-configured Tests -Spring Boot's auto-configuration system works well for applications but can sometimes be -a little too much for tests. It often helps to load only the parts of the configuration -that are required to test a "`slice`" of your application. For example, you might want to -test that Spring MVC controllers are mapping URLs correctly, and you do not want to -involve database calls in those tests, or you might want to test JPA entities, and you -are not interested in the web layer when those tests run. +Spring Boot's auto-configuration system works well for applications but can sometimes be a little too much for tests. +It often helps to load only the parts of the configuration that are required to test a "`slice`" of your application. +For example, you might want to test that Spring MVC controllers are mapping URLs correctly, and you do not want to involve database calls in those tests, or you might want to test JPA entities, and you are not interested in the web layer when those tests run. -The `spring-boot-test-autoconfigure` module includes a number of annotations that can be -used to automatically configure such "`slices`". Each of them works in a similar way, -providing a `@...Test` annotation that loads the `ApplicationContext` and one or -more `@AutoConfigure...` annotations that can be used to customize auto-configuration -settings. +The `spring-boot-test-autoconfigure` module includes a number of annotations that can be used to automatically configure such "`slices`". +Each of them works in a similar way, providing a `@...Test` annotation that loads the `ApplicationContext` and one or more `@AutoConfigure...` annotations that can be used to customize auto-configuration settings. -NOTE: Each slice restricts component scan to appropriate components and loads a very -restricted set of auto-configuration classes. If you need to exclude one of them, -most `@...Test` annotations provide an `excludeAutoConfiguration` attribute. +NOTE: Each slice restricts component scan to appropriate components and loads a very restricted set of auto-configuration classes. +If you need to exclude one of them, most `@...Test` annotations provide an `excludeAutoConfiguration` attribute. Alternatively, you can use `@ImportAutoConfiguration#exclude`. -NOTE: Including multiple "`slices`" by using several `@...Test` annotations in one test is -not supported. If you need multiple "`slices`", pick one of the `@...Test` annotations -and include the `@AutoConfigure...` annotations of the other "`slices`" by hand. +NOTE: Including multiple "`slices`" by using several `@...Test` annotations in one test is not supported. +If you need multiple "`slices`", pick one of the `@...Test` annotations and include the `@AutoConfigure...` annotations of the other "`slices`" by hand. -TIP: It is also possible to use the `@AutoConfigure...` annotations with the standard -`@SpringBootTest` annotation. You can use this combination if you are not interested in -"`slicing`" your application but you want some of the auto-configured test beans. +TIP: It is also possible to use the `@AutoConfigure...` annotations with the standard `@SpringBootTest` annotation. +You can use this combination if you are not interested in "`slicing`" your application but you want some of the auto-configured test beans. [[boot-features-testing-spring-boot-applications-testing-autoconfigured-json-tests]] ==== Auto-configured JSON Tests -To test that object JSON serialization and deserialization is working as expected, you can -use the `@JsonTest` annotation. `@JsonTest` auto-configures the available supported JSON -mapper, which can be one of the following libraries: +To test that object JSON serialization and deserialization is working as expected, you can use the `@JsonTest` annotation. +`@JsonTest` auto-configures the available supported JSON mapper, which can be one of the following libraries: * Jackson `ObjectMapper`, any `@JsonComponent` beans and any Jackson ``Module``s * `Gson` * `Jsonb` -TIP: A list of the auto-configurations that are enabled by `@JsonTest` can be -<>. +TIP: A list of the auto-configurations that are enabled by `@JsonTest` can be <>. -If you need to configure elements of the auto-configuration, you can use the -`@AutoConfigureJsonTesters` annotation. +If you need to configure elements of the auto-configuration, you can use the `@AutoConfigureJsonTesters` annotation. -Spring Boot includes AssertJ-based helpers that work with the JSONAssert and JsonPath -libraries to check that JSON appears as expected. The `JacksonTester`, `GsonTester`, -`JsonbTester`, and `BasicJsonTester` classes can be used for Jackson, Gson, Jsonb, and -Strings respectively. Any helper fields on the test class can be `@Autowired` when using -`@JsonTest`. The following example shows a test class for Jackson: +Spring Boot includes AssertJ-based helpers that work with the JSONAssert and JsonPath libraries to check that JSON appears as expected. +The `JacksonTester`, `GsonTester`, `JsonbTester`, and `BasicJsonTester` classes can be used for Jackson, Gson, Jsonb, and Strings respectively. +Any helper fields on the test class can be `@Autowired` when using `@JsonTest`. +The following example shows a test class for Jackson: [source,java,indent=0] ---- @@ -6984,15 +5822,12 @@ Strings respectively. Any helper fields on the test class can be `@Autowired` wh } ---- -NOTE: JSON helper classes can also be used directly in standard unit tests. To do so, -call the `initFields` method of the helper in your `@Before` method if you do not use -`@JsonTest`. +NOTE: JSON helper classes can also be used directly in standard unit tests. +To do so, call the `initFields` method of the helper in your `@Before` method if you do not use `@JsonTest`. -If you're using Spring Boot's AssertJ-based helpers to assert on a number value -at a given JSON path, you might not be able to use `isEqualTo` depending on the type. -Instead, you can use AssertJ's `satisfies` to assert that the value matches the given -condition. For instance, the following example asserts that the actual number is a float -value close to `0.15` within an offset of `0.01`. +If you're using Spring Boot's AssertJ-based helpers to assert on a number value at a given JSON path, you might not be able to use `isEqualTo` depending on the type. +Instead, you can use AssertJ's `satisfies` to assert that the value matches the given condition. +For instance, the following example asserts that the actual number is a float value close to `0.15` within an offset of `0.01`. [source,java,indent=0] ---- @@ -7005,27 +5840,21 @@ assertThat(json.write(message)) [[boot-features-testing-spring-boot-applications-testing-autoconfigured-mvc-tests]] ==== Auto-configured Spring MVC Tests -To test whether Spring MVC controllers are working as expected, use the `@WebMvcTest` -annotation. `@WebMvcTest` auto-configures the Spring MVC infrastructure and limits -scanned beans to `@Controller`, `@ControllerAdvice`, `@JsonComponent`, `Converter`, -`GenericConverter`, `Filter`, `WebMvcConfigurer`, and `HandlerMethodArgumentResolver`. +To test whether Spring MVC controllers are working as expected, use the `@WebMvcTest` annotation. +`@WebMvcTest` auto-configures the Spring MVC infrastructure and limits scanned beans to `@Controller`, `@ControllerAdvice`, `@JsonComponent`, `Converter`, `GenericConverter`, `Filter`, `WebMvcConfigurer`, and `HandlerMethodArgumentResolver`. Regular `@Component` beans are not scanned when using this annotation. -TIP: A list of the auto-configuration settings that are enabled by `@WebMvcTest` can be -<>. +TIP: A list of the auto-configuration settings that are enabled by `@WebMvcTest` can be <>. -TIP: If you need to register extra components, such as the Jackson `Module`, you can -import additional configuration classes by using `@Import` on your test. +TIP: If you need to register extra components, such as the Jackson `Module`, you can import additional configuration classes by using `@Import` on your test. -Often, `@WebMvcTest` is limited to a single controller and is used in combination with -`@MockBean` to provide mock implementations for required collaborators. +Often, `@WebMvcTest` is limited to a single controller and is used in combination with `@MockBean` to provide mock implementations for required collaborators. -`@WebMvcTest` also auto-configures `MockMvc`. Mock MVC offers a powerful way to quickly -test MVC controllers without needing to start a full HTTP server. +`@WebMvcTest` also auto-configures `MockMvc`. +Mock MVC offers a powerful way to quickly test MVC controllers without needing to start a full HTTP server. -TIP: You can also auto-configure `MockMvc` in a non-`@WebMvcTest` (such as -`@SpringBootTest`) by annotating it with `@AutoConfigureMockMvc`. The following example -uses `MockMvc`: +TIP: You can also auto-configure `MockMvc` in a non-`@WebMvcTest` (such as `@SpringBootTest`) by annotating it with `@AutoConfigureMockMvc`. +The following example uses `MockMvc`: [source,java,indent=0] ---- @@ -7061,13 +5890,10 @@ uses `MockMvc`: } ---- -TIP: If you need to configure elements of the auto-configuration (for example, when -servlet filters should be applied) you can use attributes in the `@AutoConfigureMockMvc` -annotation. - -If you use HtmlUnit or Selenium, auto-configuration also provides an HTMLUnit `WebClient` -bean and/or a `WebDriver` bean. The following example uses HtmlUnit: +TIP: If you need to configure elements of the auto-configuration (for example, when servlet filters should be applied) you can use attributes in the `@AutoConfigureMockMvc` annotation. +If you use HtmlUnit or Selenium, auto-configuration also provides an HTMLUnit `WebClient` bean and/or a `WebDriver` bean. +The following example uses HtmlUnit: [source,java,indent=0] ---- @@ -7102,52 +5928,36 @@ bean and/or a `WebDriver` bean. The following example uses HtmlUnit: } ---- -NOTE: By default, Spring Boot puts `WebDriver` beans in a special "`scope`" to ensure -that the driver exits after each test and that a new instance is injected. If you do -not want this behavior, you can add `@Scope("singleton")` to your `WebDriver` `@Bean` -definition. +NOTE: By default, Spring Boot puts `WebDriver` beans in a special "`scope`" to ensure that the driver exits after each test and that a new instance is injected. +If you do not want this behavior, you can add `@Scope("singleton")` to your `WebDriver` `@Bean` definition. -WARNING: The `webDriver` scope created by Spring Boot will replace any user defined scope -of the same name. If you define your own `webDriver` scope you may find it stops working -when you use `@WebMvcTest`. +WARNING: The `webDriver` scope created by Spring Boot will replace any user defined scope of the same name. +If you define your own `webDriver` scope you may find it stops working when you use `@WebMvcTest`. -If you have Spring Security on the classpath, `@WebMvcTest` will also scan `WebSecurityConfigurer` -beans. Instead of disabling security completely for such tests, you can use Spring Security's test support. -More details on how to use Spring Security's `MockMvc` support can be found in -this _<>_ how-to section. +If you have Spring Security on the classpath, `@WebMvcTest` will also scan `WebSecurityConfigurer` beans. +Instead of disabling security completely for such tests, you can use Spring Security's test support. +More details on how to use Spring Security's `MockMvc` support can be found in this _<>_ how-to section. -TIP: Sometimes writing Spring MVC tests is not enough; Spring Boot can help you run -<>. +TIP: Sometimes writing Spring MVC tests is not enough; Spring Boot can help you run <>. [[boot-features-testing-spring-boot-applications-testing-autoconfigured-webflux-tests]] ==== Auto-configured Spring WebFlux Tests -To test that {spring-reference}/web-reactive.html[Spring WebFlux] controllers are -working as expected, you can use the `@WebFluxTest` annotation. `@WebFluxTest` -auto-configures the Spring WebFlux infrastructure and limits scanned beans to -`@Controller`, `@ControllerAdvice`, `@JsonComponent`, `Converter`, `GenericConverter`, and -`WebFluxConfigurer`. Regular `@Component` beans are not scanned when the `@WebFluxTest` -annotation is used. +To test that {spring-reference}/web-reactive.html[Spring WebFlux] controllers are working as expected, you can use the `@WebFluxTest` annotation. +`@WebFluxTest` auto-configures the Spring WebFlux infrastructure and limits scanned beans to `@Controller`, `@ControllerAdvice`, `@JsonComponent`, `Converter`, `GenericConverter`, and `WebFluxConfigurer`. +Regular `@Component` beans are not scanned when the `@WebFluxTest` annotation is used. -TIP: A list of the auto-configurations that are enabled by `@WebFluxTest` can be -<>. +TIP: A list of the auto-configurations that are enabled by `@WebFluxTest` can be <>. -TIP: If you need to register extra components, such as Jackson `Module`, you can import -additional configuration classes using `@Import` on your test. +TIP: If you need to register extra components, such as Jackson `Module`, you can import additional configuration classes using `@Import` on your test. -Often, `@WebFluxTest` is limited to a single controller and used in combination with the -`@MockBean` annotation to provide mock implementations for required collaborators. +Often, `@WebFluxTest` is limited to a single controller and used in combination with the `@MockBean` annotation to provide mock implementations for required collaborators. -`@WebFluxTest` also auto-configures -{spring-reference}testing.html#webtestclient[`WebTestClient`], which offers -a powerful way to quickly test WebFlux controllers without needing to start a full HTTP -server. +`@WebFluxTest` also auto-configures {spring-reference}testing.html#webtestclient[`WebTestClient`], which offers a powerful way to quickly test WebFlux controllers without needing to start a full HTTP server. -TIP: You can also auto-configure `WebTestClient` in a non-`@WebFluxTest` (such as -`@SpringBootTest`) by annotating it with `@AutoConfigureWebTestClient`. The following -example shows a class that uses both `@WebFluxTest` and a `WebTestClient`: +TIP: You can also auto-configure `WebTestClient` in a non-`@WebFluxTest` (such as `@SpringBootTest`) by annotating it with `@AutoConfigureWebTestClient`. +The following example shows a class that uses both `@WebFluxTest` and a `WebTestClient`: [source,java,indent=0] ---- @@ -7183,38 +5993,30 @@ example shows a class that uses both `@WebFluxTest` and a `WebTestClient`: } ---- -TIP: This setup is only supported by WebFlux applications as using `WebTestClient` in a -mocked web application only works with WebFlux at the moment. +TIP: This setup is only supported by WebFlux applications as using `WebTestClient` in a mocked web application only works with WebFlux at the moment. -NOTE: `@WebFluxTest` cannot detect routes registered via the functional web framework. For -testing `RouterFunction` beans in the context, consider importing your `RouterFunction` -yourself via `@Import` or using `@SpringBootTest`. +NOTE: `@WebFluxTest` cannot detect routes registered via the functional web framework. +For testing `RouterFunction` beans in the context, consider importing your `RouterFunction` yourself via `@Import` or using `@SpringBootTest`. -NOTE: `@WebFluxTest` cannot detect custom security configuration registered via a `@Bean` -of type `SecurityWebFilterChain`. To include that in your test, you will need to import -the configuration that registers the bean via `@Import` or use `@SpringBootTest`. +NOTE: `@WebFluxTest` cannot detect custom security configuration registered via a `@Bean` of type `SecurityWebFilterChain`. +To include that in your test, you will need to import the configuration that registers the bean via `@Import` or use `@SpringBootTest`. -TIP: Sometimes writing Spring WebFlux tests is not enough; Spring Boot can help you run -<>. +TIP: Sometimes writing Spring WebFlux tests is not enough; Spring Boot can help you run <>. [[boot-features-testing-spring-boot-applications-testing-autoconfigured-jpa-test]] ==== Auto-configured Data JPA Tests -You can use the `@DataJpaTest` annotation to test JPA applications. By default, it scans -for `@Entity` classes and configures Spring Data JPA repositories. If an embedded database -is available on the classpath, it configures one as well. Regular `@Component` beans are -not loaded into the `ApplicationContext`. +You can use the `@DataJpaTest` annotation to test JPA applications. +By default, it scans for `@Entity` classes and configures Spring Data JPA repositories. +If an embedded database is available on the classpath, it configures one as well. +Regular `@Component` beans are not loaded into the `ApplicationContext`. -TIP: A list of the auto-configuration settings that are enabled by `@DataJpaTest` can be -<>. +TIP: A list of the auto-configuration settings that are enabled by `@DataJpaTest` can be <>. -By default, data JPA tests are transactional and roll back at the end of each test. See -the {spring-reference}testing.html#testcontext-tx-enabling-transactions[relevant section] -in the Spring Framework Reference Documentation for more details. If that is not what you -want, you can disable transaction management for a test or for the whole class as -follows: +By default, data JPA tests are transactional and roll back at the end of each test. +See the {spring-reference}testing.html#testcontext-tx-enabling-transactions[relevant section] in the Spring Framework Reference Documentation for more details. +If that is not what you want, you can disable transaction management for a test or for the whole class as follows: [source,java,indent=0] ---- @@ -7233,13 +6035,9 @@ follows: } ---- -Data JPA tests may also inject a -{sc-spring-boot-test-autoconfigure}/orm/jpa/TestEntityManager.{sc-ext}[`TestEntityManager`] -bean, which provides an alternative to the standard JPA `EntityManager` that is -specifically designed for tests. If you want to use `TestEntityManager` outside of -`@DataJpaTest` instances, you can also use the `@AutoConfigureTestEntityManager` -annotation. A `JdbcTemplate` is also available if you need that. The following example -shows the `@DataJpaTest` annotation in use: +Data JPA tests may also inject a {sc-spring-boot-test-autoconfigure}/orm/jpa/TestEntityManager.{sc-ext}[`TestEntityManager`] bean, which provides an alternative to the standard JPA `EntityManager` that is specifically designed for tests. +If you want to use `TestEntityManager` outside of `@DataJpaTest` instances, you can also use the `@AutoConfigureTestEntityManager` annotation. +A `JdbcTemplate` is also available if you need that. The following example shows the `@DataJpaTest` annotation in use: [source,java,indent=0] ---- @@ -7270,10 +6068,8 @@ shows the `@DataJpaTest` annotation in use: } ---- -In-memory embedded databases generally work well for tests, since they are fast and do -not require any installation. If, however, you prefer to run tests against a real -database you can use the `@AutoConfigureTestDatabase` annotation, as shown in the -following example: +In-memory embedded databases generally work well for tests, since they are fast and do not require any installation. +If, however, you prefer to run tests against a real database you can use the `@AutoConfigureTestDatabase` annotation, as shown in the following example: [source,java,indent=0] ---- @@ -7291,19 +6087,15 @@ following example: [[boot-features-testing-spring-boot-applications-testing-autoconfigured-jdbc-test]] ==== Auto-configured JDBC Tests -`@JdbcTest` is similar to `@DataJpaTest` but is for tests that only require a -`DataSource` and do not use Spring Data JDBC. By default, it configures an in-memory -embedded database and a `JdbcTemplate`. Regular `@Component` beans are not loaded into -the `ApplicationContext`. +`@JdbcTest` is similar to `@DataJpaTest` but is for tests that only require a `DataSource` and do not use Spring Data JDBC. +By default, it configures an in-memory embedded database and a `JdbcTemplate`. +Regular `@Component` beans are not loaded into the `ApplicationContext`. -TIP: A list of the auto-configurations that are enabled by `@JdbcTest` can be -<>. +TIP: A list of the auto-configurations that are enabled by `@JdbcTest` can be <>. -By default, JDBC tests are transactional and roll back at the end of each test. See the -{spring-reference}testing.html#testcontext-tx-enabling-transactions[relevant section] in -the Spring Framework Reference Documentation for more details. If that is not what you -want, you can disable transaction management for a test or for the whole class, as -follows: +By default, JDBC tests are transactional and roll back at the end of each test. +See the {spring-reference}testing.html#testcontext-tx-enabling-transactions[relevant section] in the Spring Framework Reference Documentation for more details. +If that is not what you want, you can disable transaction management for a test or for the whole class, as follows: [source,java,indent=0] ---- @@ -7322,49 +6114,41 @@ follows: } ---- -If you prefer your test to run against a real database, you can use the -`@AutoConfigureTestDatabase` annotation in the same way as for `DataJpaTest`. (See -"<>".) +If you prefer your test to run against a real database, you can use the `@AutoConfigureTestDatabase` annotation in the same way as for `DataJpaTest`. +(See "<>".) [[boot-features-testing-spring-boot-applications-testing-autoconfigured-data-jdbc-test]] ==== Auto-configured Data JDBC Tests -`@DataJdbcTest` is similar to `@JdbcTest` but is for tests that use Spring Data JDBC -repositories. By default, it configures an in-memory embedded database, a `JdbcTemplate`, -and Spring Data JDBC repositories. Regular `@Component` beans are not loaded into -the `ApplicationContext`. +`@DataJdbcTest` is similar to `@JdbcTest` but is for tests that use Spring Data JDBC repositories. +By default, it configures an in-memory embedded database, a `JdbcTemplate`, and Spring Data JDBC repositories. +Regular `@Component` beans are not loaded into the `ApplicationContext`. -TIP: A list of the auto-configurations that are enabled by `@DataJdbcTest` can be -<>. +TIP: A list of the auto-configurations that are enabled by `@DataJdbcTest` can be <>. -By default, Data JDBC tests are transactional and roll back at the end of each test. See -the {spring-reference}testing.html#testcontext-tx-enabling-transactions[relevant section] -in the Spring Framework Reference Documentation for more details. If that is not what you -want, you can disable transaction management for a test or for the whole test class as -<>. +By default, Data JDBC tests are transactional and roll back at the end of each test. +See the {spring-reference}testing.html#testcontext-tx-enabling-transactions[relevant section] in the Spring Framework Reference Documentation for more details. +If that is not what you want, you can disable transaction management for a test or for the whole test class as <>. -If you prefer your test to run against a real database, you can use the -`@AutoConfigureTestDatabase` annotation in the same way as for `DataJpaTest`. (See -"<>".) +If you prefer your test to run against a real database, you can use the `@AutoConfigureTestDatabase` annotation in the same way as for `DataJpaTest`. +(See "<>".) [[boot-features-testing-spring-boot-applications-testing-autoconfigured-jooq-test]] ==== Auto-configured jOOQ Tests You can use `@JooqTest` in a similar fashion as `@JdbcTest` but for jOOQ-related tests. -As jOOQ relies heavily on a Java-based schema that corresponds with the database schema, -the existing `DataSource` is used. If you want to replace it with an in-memory database, -you can use `@AutoConfigureTestDatabase` to override those settings. (For more about using -jOOQ with Spring Boot, see "<>", earlier in this chapter.) Regular -`@Component` beans are not loaded into the `ApplicationContext`. +As jOOQ relies heavily on a Java-based schema that corresponds with the database schema, the existing `DataSource` is used. +If you want to replace it with an in-memory database, you can use `@AutoConfigureTestDatabase` to override those settings. +(For more about using jOOQ with Spring Boot, see "<>", earlier in this chapter.) +Regular `@Component` beans are not loaded into the `ApplicationContext`. -TIP: A list of the auto-configurations that are enabled by `@JooqTest` can be -<>. +TIP: A list of the auto-configurations that are enabled by `@JooqTest` can be <>. -`@JooqTest` configures a `DSLContext`. Regular `@Component` beans are not loaded into the -`ApplicationContext`. The following example shows the `@JooqTest` annotation in use: +`@JooqTest` configures a `DSLContext`. +Regular `@Component` beans are not loaded into the `ApplicationContext`. +The following example shows the `@JooqTest` annotation in use: [source,java,indent=0] ---- @@ -7383,25 +6167,19 @@ TIP: A list of the auto-configurations that are enabled by `@JooqTest` can be } ---- -JOOQ tests are transactional and roll back at the end of each test by default. If that is -not what you want, you can disable transaction management for a test or for the whole -test class as -<>. - +JOOQ tests are transactional and roll back at the end of each test by default. +If that is not what you want, you can disable transaction management for a test or for the whole test class as <>. [[boot-features-testing-spring-boot-applications-testing-autoconfigured-mongo-test]] ==== Auto-configured Data MongoDB Tests -You can use `@DataMongoTest` to test MongoDB applications. By default, it configures an -in-memory embedded MongoDB (if available), configures a `MongoTemplate`, scans for -`@Document` classes, and configures Spring Data MongoDB repositories. Regular -`@Component` beans are not loaded into the `ApplicationContext`. (For more about using -MongoDB with Spring Boot, see "<>", earlier in this chapter.) +You can use `@DataMongoTest` to test MongoDB applications. +By default, it configures an in-memory embedded MongoDB (if available), configures a `MongoTemplate`, scans for `@Document` classes, and configures Spring Data MongoDB repositories. +Regular `@Component` beans are not loaded into the `ApplicationContext`. +(For more about using MongoDB with Spring Boot, see "<>", earlier in this chapter.) -TIP: A list of the auto-configuration settings that are enabled by `@DataMongoTest` can be -<>. +TIP: A list of the auto-configuration settings that are enabled by `@DataMongoTest` can be <>. The following class shows the `@DataMongoTest` annotation in use: @@ -7424,15 +6202,13 @@ The following class shows the `@DataMongoTest` annotation in use: } ---- -In-memory embedded MongoDB generally works well for tests, since it is fast and does not -require any developer installation. If, however, you prefer to run tests against a real -MongoDB server, you should exclude the embedded MongoDB auto-configuration, as shown in -the following example: +In-memory embedded MongoDB generally works well for tests, since it is fast and does not require any developer installation. +If, however, you prefer to run tests against a real MongoDB server, you should exclude the embedded MongoDB auto-configuration, as shown in the following example: [source,java,indent=0] ---- import org.junit.runner.RunWith; - import org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration; + import org.springframework.boot.autoconfigure.mongo.embedded.EmbeddedMongoAutoConfiguration; import org.springframework.boot.test.autoconfigure.data.mongo.DataMongoTest; import org.springframework.test.context.junit4.SpringRunner; @@ -7445,17 +6221,14 @@ the following example: - [[boot-features-testing-spring-boot-applications-testing-autoconfigured-neo4j-test]] ==== Auto-configured Data Neo4j Tests -You can use `@DataNeo4jTest` to test Neo4j applications. By default, it uses an in-memory -embedded Neo4j (if the embedded driver is available), scans for `@NodeEntity` classes, and -configures Spring Data Neo4j repositories. Regular `@Component` beans are not loaded into -the `ApplicationContext`. (For more about using Neo4J with Spring Boot, see -"<>", earlier in this chapter.) +You can use `@DataNeo4jTest` to test Neo4j applications. +By default, it uses an in-memory embedded Neo4j (if the embedded driver is available), scans for `@NodeEntity` classes, and configures Spring Data Neo4j repositories. +Regular `@Component` beans are not loaded into the `ApplicationContext`. +(For more about using Neo4J with Spring Boot, see "<>", earlier in this chapter.) -TIP: A list of the auto-configuration settings that are enabled by `@DataNeo4jTest` can be -<>. +TIP: A list of the auto-configuration settings that are enabled by `@DataNeo4jTest` can be <>. The following example shows a typical setup for using Neo4J tests in Spring Boot: @@ -7478,10 +6251,8 @@ The following example shows a typical setup for using Neo4J tests in Spring Boot ---- By default, Data Neo4j tests are transactional and roll back at the end of each test. -See the {spring-reference}testing.html#testcontext-tx-enabling-transactions[relevant -section] in the Spring Framework Reference Documentation for more details. If that is not -what you want, you can disable transaction management for a test or for the whole class, -as follows: +See the {spring-reference}testing.html#testcontext-tx-enabling-transactions[relevant section] in the Spring Framework Reference Documentation for more details. +If that is not what you want, you can disable transaction management for a test or for the whole class, as follows: [source,java,indent=0] ---- @@ -7502,16 +6273,14 @@ as follows: - [[boot-features-testing-spring-boot-applications-testing-autoconfigured-redis-test]] ==== Auto-configured Data Redis Tests -You can use `@DataRedisTest` to test Redis applications. By default, it scans for -`@RedisHash` classes and configures Spring Data Redis repositories. Regular `@Component` -beans are not loaded into the `ApplicationContext`. (For more about using Redis with -Spring Boot, see "<>", earlier in this chapter.) +You can use `@DataRedisTest` to test Redis applications. +By default, it scans for `@RedisHash` classes and configures Spring Data Redis repositories. +Regular `@Component` beans are not loaded into the `ApplicationContext`. +(For more about using Redis with Spring Boot, see "<>", earlier in this chapter.) -TIP: A list of the auto-configuration settings that are enabled by `@DataRedisTest` can be -<>. +TIP: A list of the auto-configuration settings that are enabled by `@DataRedisTest` can be <>. The following example shows the `@DataRedisTest` annotation in use: @@ -7537,14 +6306,12 @@ The following example shows the `@DataRedisTest` annotation in use: [[boot-features-testing-spring-boot-applications-testing-autoconfigured-ldap-test]] ==== Auto-configured Data LDAP Tests -You can use `@DataLdapTest` to test LDAP applications. By default, it configures an -in-memory embedded LDAP (if available), configures an `LdapTemplate`, scans for `@Entry` -classes, and configures Spring Data LDAP repositories. Regular `@Component` beans are not -loaded into the `ApplicationContext`. (For more about using LDAP with -Spring Boot, see "<>", earlier in this chapter.) +You can use `@DataLdapTest` to test LDAP applications. +By default, it configures an in-memory embedded LDAP (if available), configures an `LdapTemplate`, scans for `@Entry` classes, and configures Spring Data LDAP repositories. +Regular `@Component` beans are not loaded into the `ApplicationContext`. +(For more about using LDAP with Spring Boot, see "<>", earlier in this chapter.) -TIP: A list of the auto-configuration settings that are enabled by `@DataLdapTest` can be -<>. +TIP: A list of the auto-configuration settings that are enabled by `@DataLdapTest` can be <>. The following example shows the `@DataLdapTest` annotation in use: @@ -7567,10 +6334,8 @@ The following example shows the `@DataLdapTest` annotation in use: } ---- -In-memory embedded LDAP generally works well for tests, since it is fast and does not -require any developer installation. If, however, you prefer to run tests against a real -LDAP server, you should exclude the embedded LDAP auto-configuration, as shown in the -following example: +In-memory embedded LDAP generally works well for tests, since it is fast and does not require any developer installation. +If, however, you prefer to run tests against a real LDAP server, you should exclude the embedded LDAP auto-configuration, as shown in the following example: [source,java,indent=0] ---- @@ -7590,16 +6355,13 @@ following example: [[boot-features-testing-spring-boot-applications-testing-autoconfigured-rest-client]] ==== Auto-configured REST Clients -You can use the `@RestClientTest` annotation to test REST clients. By default, it -auto-configures Jackson, GSON, and Jsonb support, configures a `RestTemplateBuilder`, and -adds support for `MockRestServiceServer`. Regular `@Component` beans are not loaded into -the `ApplicationContext`. +You can use the `@RestClientTest` annotation to test REST clients. +By default, it auto-configures Jackson, GSON, and Jsonb support, configures a `RestTemplateBuilder`, and adds support for `MockRestServiceServer`. +Regular `@Component` beans are not loaded into the `ApplicationContext`. -TIP: A list of the auto-configuration settings that are enabled by `@RestClientTest` can -be <>. +TIP: A list of the auto-configuration settings that are enabled by `@RestClientTest` can be <>. -The specific beans that you want to test should be specified by using the `value` or -`components` attribute of `@RestClientTest`, as shown in the following example: +The specific beans that you want to test should be specified by using the `value` or `components` attribute of `@RestClientTest`, as shown in the following example: [source,java,indent=0] ---- @@ -7629,22 +6391,18 @@ The specific beans that you want to test should be specified by using the `value [[boot-features-testing-spring-boot-applications-testing-autoconfigured-rest-docs]] ==== Auto-configured Spring REST Docs Tests -You can use the `@AutoConfigureRestDocs` annotation to use {spring-rest-docs}[Spring REST -Docs] in your tests with Mock MVC, REST Assured, or WebTestClient. It removes the need for -the JUnit rule in Spring REST Docs. +You can use the `@AutoConfigureRestDocs` annotation to use {spring-rest-docs}[Spring REST Docs] in your tests with Mock MVC, REST Assured, or WebTestClient. +It removes the need for the JUnit rule in Spring REST Docs. -`@AutoConfigureRestDocs` can be used to override the default output directory -(`target/generated-snippets` if you are using Maven or `build/generated-snippets` if you -are using Gradle). It can also be used to configure the host, scheme, and port that -appears in any documented URIs. +`@AutoConfigureRestDocs` can be used to override the default output directory (`target/generated-snippets` if you are using Maven or `build/generated-snippets` if you are using Gradle). +It can also be used to configure the host, scheme, and port that appears in any documented URIs. [[boot-features-testing-spring-boot-applications-testing-autoconfigured-rest-docs-mock-mvc]] ===== Auto-configured Spring REST Docs Tests with Mock MVC -`@AutoConfigureRestDocs` customizes the `MockMvc` bean to use Spring REST Docs. You can -inject it by using `@Autowired` and use it in your tests as you normally would when using -Mock MVC and Spring REST Docs, as shown in the following example: +`@AutoConfigureRestDocs` customizes the `MockMvc` bean to use Spring REST Docs. +You can inject it by using `@Autowired` and use it in your tests as you normally would when using Mock MVC and Spring REST Docs, as shown in the following example: [source,java,indent=0] ---- @@ -7679,9 +6437,7 @@ Mock MVC and Spring REST Docs, as shown in the following example: } ---- -If you require more control over Spring REST Docs configuration than offered by the -attributes of `@AutoConfigureRestDocs`, you can use a -`RestDocsMockMvcConfigurationCustomizer` bean, as shown in the following example: +If you require more control over Spring REST Docs configuration than offered by the attributes of `@AutoConfigureRestDocs`, you can use a `RestDocsMockMvcConfigurationCustomizer` bean, as shown in the following example: [source,java,indent=0] ---- @@ -7697,11 +6453,9 @@ attributes of `@AutoConfigureRestDocs`, you can use a } ---- -If you want to make use of Spring REST Docs support for a parameterized output directory, -you can create a `RestDocumentationResultHandler` bean. The auto-configuration calls -`alwaysDo` with this result handler, thereby causing each `MockMvc` call to automatically -generate the default snippets. The following example shows a -`RestDocumentationResultHandler` being defined: +If you want to make use of Spring REST Docs support for a parameterized output directory, you can create a `RestDocumentationResultHandler` bean. +The auto-configuration calls `alwaysDo` with this result handler, thereby causing each `MockMvc` call to automatically generate the default snippets. +The following example shows a `RestDocumentationResultHandler` being defined: [source,java,indent=0] ---- @@ -7720,18 +6474,15 @@ generate the default snippets. The following example shows a [[boot-features-testing-spring-boot-applications-testing-autoconfigured-rest-docs-web-test-client]] ===== Auto-configured Spring REST Docs Tests with WebTestClient -`@AutoConfigureRestDocs` can also be used with `WebTestClient`. You can inject it by using -`@Autowired` and use it in your tests as you normally would when using `@WebFluxTest` and -Spring REST Docs, as shown in the following example: +`@AutoConfigureRestDocs` can also be used with `WebTestClient`. +You can inject it by using `@Autowired` and use it in your tests as you normally would when using `@WebFluxTest` and Spring REST Docs, as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/test/autoconfigure/restdocs/webclient/UsersDocumentationTests.java[tag=source] ---- -If you require more control over Spring REST Docs configuration than offered by the -attributes of `@AutoConfigureRestDocs`, you can use a -`RestDocsWebTestClientConfigurationCustomizer` bean, as shown in the following example: +If you require more control over Spring REST Docs configuration than offered by the attributes of `@AutoConfigureRestDocs`, you can use a `RestDocsWebTestClientConfigurationCustomizer` bean, as shown in the following example: [source,java,indent=0] ---- @@ -7742,19 +6493,15 @@ include::{code-examples}/test/autoconfigure/restdocs/webclient/AdvancedConfigura [[boot-features-testing-spring-boot-applications-testing-autoconfigured-rest-docs-rest-assured]] ===== Auto-configured Spring REST Docs Tests with REST Assured -`@AutoConfigureRestDocs` makes a `RequestSpecification` bean, preconfigured to use Spring -REST Docs, available to your tests. You can inject it by using `@Autowired` and use it in -your tests as you normally would when using REST Assured and Spring REST Docs, as shown -in the following example: +`@AutoConfigureRestDocs` makes a `RequestSpecification` bean, preconfigured to use Spring REST Docs, available to your tests. +You can inject it by using `@Autowired` and use it in your tests as you normally would when using REST Assured and Spring REST Docs, as shown in the following example: [source,java,indent=0] ---- include::{code-examples}/test/autoconfigure/restdocs/restassured/UserDocumentationTests.java[tag=source] ---- -If you require more control over Spring REST Docs configuration than offered by the -attributes of `@AutoConfigureRestDocs`, a `RestDocsRestAssuredConfigurationCustomizer` -bean can be used, as shown in the following example: +If you require more control over Spring REST Docs configuration than offered by the attributes of `@AutoConfigureRestDocs`, a `RestDocsRestAssuredConfigurationCustomizer` bean can be used, as shown in the following example: [source,java,indent=0] ---- @@ -7765,10 +6512,8 @@ include::{code-examples}/test/autoconfigure/restdocs/restassured/AdvancedConfigu [[boot-features-testing-spring-boot-applications-testing-auto-configured-additional-auto-config]] ==== Additional Auto-configuration and Slicing -Each slice provides one or more `@AutoConfigure...` annotations that namely defines the -auto-configurations that should be included as part of a slice. Additional -auto-configurations can be added by creating a custom `@AutoConfigure...` annotation or -simply by adding `@ImportAutoConfiguration` to the test as shown in the following example: +Each slice provides one or more `@AutoConfigure...` annotations that namely defines the auto-configurations that should be included as part of a slice. +Additional auto-configurations can be added by creating a custom `@AutoConfigure...` annotation or simply by adding `@ImportAutoConfiguration` to the test as shown in the following example: [source,java,indent=0] ---- @@ -7780,20 +6525,15 @@ simply by adding `@ImportAutoConfiguration` to the test as shown in the followin } ---- -NOTE: Make sure to not use the regular `@Import` annotation to import auto-configurations -as they are handled in a specific way by Spring Boot. +NOTE: Make sure to not use the regular `@Import` annotation to import auto-configurations as they are handled in a specific way by Spring Boot. [[boot-features-testing-spring-boot-applications-testing-user-configuration]] ==== User Configuration and Slicing -If you <> in a sensible way, your -`@SpringBootApplication` class is -<> as -the configuration of your tests. +If you <> in a sensible way, your `@SpringBootApplication` class is <> as the configuration of your tests. -It then becomes important not to litter the application's main class with configuration -settings that are specific to a particular area of its functionality. +It then becomes important not to litter the application's main class with configuration settings that are specific to a particular area of its functionality. Assume that you are using Spring Batch and you rely on the auto-configuration for it. You could define your `@SpringBootApplication` as follows: @@ -7805,10 +6545,8 @@ You could define your `@SpringBootApplication` as follows: public class SampleApplication { ... } ---- -Because this class is the source configuration for the test, any slice test actually -tries to start Spring Batch, which is definitely not what you want to do. A recommended -approach is to move that area-specific configuration to a separate `@Configuration` class -at the same level as your application, as shown in the following example: +Because this class is the source configuration for the test, any slice test actually tries to start Spring Batch, which is definitely not what you want to do. +A recommended approach is to move that area-specific configuration to a separate `@Configuration` class at the same level as your application, as shown in the following example: [source,java,indent=0] ---- @@ -7817,14 +6555,11 @@ at the same level as your application, as shown in the following example: public class BatchConfiguration { ... } ---- -NOTE: Depending on the complexity of your application, you may either have a single -`@Configuration` class for your customizations or one class per domain area. The latter -approach lets you enable it in one of your tests, if necessary, with the `@Import` -annotation. +NOTE: Depending on the complexity of your application, you may either have a single `@Configuration` class for your customizations or one class per domain area. +The latter approach lets you enable it in one of your tests, if necessary, with the `@Import` annotation. -Test slices exclude `@Configuration` classes from scanning. For example, for a `@WebMvcTest`, -the following configuration will not include the given `WebMvcConfigurer` bean in the application -context loaded by the test slice: +Test slices exclude `@Configuration` classes from scanning. +For example, for a `@WebMvcTest`, the following configuration will not include the given `WebMvcConfigurer` bean in the application context loaded by the test slice: [source,java,indent=0] ---- @@ -7839,8 +6574,7 @@ context loaded by the test slice: } ---- -The configuration below will, however, cause the custom `WebMvcConfigurer` to be loaded -by the test slice. +The configuration below will, however, cause the custom `WebMvcConfigurer` to be loaded by the test slice. [source,java,indent=0] ---- @@ -7850,9 +6584,9 @@ by the test slice. } ---- -Another source of confusion is classpath scanning. Assume that, while you structured your -code in a sensible way, you need to scan an additional package. Your application may -resemble the following code: +Another source of confusion is classpath scanning. +Assume that, while you structured your code in a sensible way, you need to scan an additional package. +Your application may resemble the following code: [source,java,indent=0] ---- @@ -7861,42 +6595,34 @@ resemble the following code: public class SampleApplication { ... } ---- -Doing so effectively overrides the default component scan directive with the side effect -of scanning those two packages regardless of the slice that you chose. For instance, a -`@DataJpaTest` seems to suddenly scan components and user configurations of your -application. Again, moving the custom directive to a separate class is a good way to fix -this issue. +Doing so effectively overrides the default component scan directive with the side effect of scanning those two packages regardless of the slice that you chose. +For instance, a `@DataJpaTest` seems to suddenly scan components and user configurations of your application. +Again, moving the custom directive to a separate class is a good way to fix this issue. -TIP: If this is not an option for you, you can create a `@SpringBootConfiguration` -somewhere in the hierarchy of your test so that it is used instead. Alternatively, you -can specify a source for your test, which disables the behavior of finding a default one. +TIP: If this is not an option for you, you can create a `@SpringBootConfiguration` somewhere in the hierarchy of your test so that it is used instead. +Alternatively, you can specify a source for your test, which disables the behavior of finding a default one. [[boot-features-testing-spring-boot-applications-with-spock]] ==== Using Spock to Test Spring Boot Applications -If you wish to use Spock to test a Spring Boot application, you should add a dependency -on Spock's `spock-spring` module to your application's build. `spock-spring` integrates -Spring's test framework into Spock. It is recommended that you use Spock 1.2 or later to -benefit from a number of improvements to Spock's Spring Framework and Spring Boot -integration. See http://spockframework.org/spock/docs/1.2/modules.html#_spring_module[the -documentation for Spock's Spring module] for further details. +If you wish to use Spock to test a Spring Boot application, you should add a dependency on Spock's `spock-spring` module to your application's build. +`spock-spring` integrates Spring's test framework into Spock. +It is recommended that you use Spock 1.2 or later to benefit from a number of improvements to Spock's Spring Framework and Spring Boot integration. +See http://spockframework.org/spock/docs/1.2/modules.html#_spring_module[the documentation for Spock's Spring module] for further details. [[boot-features-test-utilities]] === Test Utilities -A few test utility classes that are generally useful when testing your application are -packaged as part of `spring-boot`. +A few test utility classes that are generally useful when testing your application are packaged as part of `spring-boot`. [[boot-features-configfileapplicationcontextinitializer-test-utility]] ==== ConfigFileApplicationContextInitializer -`ConfigFileApplicationContextInitializer` is an `ApplicationContextInitializer` that you -can apply to your tests to load Spring Boot `application.properties` files. You can use -it when you do not need the full set of features provided by `@SpringBootTest`, as shown -in the following example: +`ConfigFileApplicationContextInitializer` is an `ApplicationContextInitializer` that you can apply to your tests to load Spring Boot `application.properties` files. +You can use it when you do not need the full set of features provided by `@SpringBootTest`, as shown in the following example: [source,java,indent=0] ---- @@ -7904,19 +6630,16 @@ in the following example: initializers = ConfigFileApplicationContextInitializer.class) ---- -NOTE: Using `ConfigFileApplicationContextInitializer` alone does not provide support for -`@Value("${...}")` injection. Its only job is to ensure that `application.properties` -files are loaded into Spring's `Environment`. For `@Value` support, you need to either -additionally configure a `PropertySourcesPlaceholderConfigurer` or use `@SpringBootTest`, -which auto-configures one for you. +NOTE: Using `ConfigFileApplicationContextInitializer` alone does not provide support for `@Value("${...}")` injection. +Its only job is to ensure that `application.properties` files are loaded into Spring's `Environment`. +For `@Value` support, you need to either additionally configure a `PropertySourcesPlaceholderConfigurer` or use `@SpringBootTest`, which auto-configures one for you. [[boot-features-test-property-values]] ==== TestPropertyValues -`TestPropertyValues` lets you quickly add properties to a -`ConfigurableEnvironment` or `ConfigurableApplicationContext`. You can call it with -`key=value` strings, as follows: +`TestPropertyValues` lets you quickly add properties to a `ConfigurableEnvironment` or `ConfigurableApplicationContext`. +You can call it with `key=value` strings, as follows: [source,java,indent=0] ---- @@ -7927,9 +6650,8 @@ which auto-configures one for you. [[boot-features-output-capture-test-utility]] ==== OutputCapture -`OutputCapture` is a JUnit `Rule` that you can use to capture `System.out` and -`System.err` output. You can declare the capture as a `@Rule` and then use `toString()` -for assertions, as follows: +`OutputCapture` is a JUnit `Rule` that you can use to capture `System.out` and `System.err` output. +You can declare the capture as a `@Rule` and then use `toString()` for assertions, as follows: [source,java,indent=0] ---- @@ -7940,29 +6662,21 @@ include::{test-examples}/test/rule/OutputCaptureTests.java[tag=test] [[boot-features-rest-templates-test-utility]] ==== TestRestTemplate +`TestRestTemplate` is a convenience alternative to Spring's `RestTemplate` that is useful in integration tests. +You can get a vanilla template or one that sends Basic HTTP authentication (with a username and password). +In either case, the template behaves in a test-friendly way by not throwing exceptions on server-side errors. -TIP: Spring Framework 5.0 provides a new `WebTestClient` that works for -<> and both -<>. It provides a fluent API for assertions, -unlike `TestRestTemplate`. +TIP: Spring Framework 5.0 provides a new `WebTestClient` that works for <> and both <>. +It provides a fluent API for assertions, unlike `TestRestTemplate`. - -`TestRestTemplate` is a convenience alternative to Spring's `RestTemplate` that is useful -in integration tests. You can get a vanilla template or one that sends Basic HTTP -authentication (with a username and password). In either case, the template behaves in a -test-friendly way by not throwing exceptions on server-side errors. It is recommended, -but not mandatory, to use the Apache HTTP Client (version 4.3.2 or better). If you have -that on your classpath, the `TestRestTemplate` responds by configuring the client -appropriately. If you do use Apache's HTTP client, some additional test-friendly features -are enabled: +It is recommended, but not mandatory, to use the Apache HTTP Client (version 4.3.2 or better). +If you have that on your classpath, the `TestRestTemplate` responds by configuring the client appropriately. +If you do use Apache's HTTP client, some additional test-friendly features are enabled: * Redirects are not followed (so you can assert the response location). * Cookies are ignored (so the template is stateless). -`TestRestTemplate` can be instantiated directly in your integration tests, as shown in -the following example: +`TestRestTemplate` can be instantiated directly in your integration tests, as shown in the following example: [source,java,indent=0] ---- @@ -7980,12 +6694,9 @@ the following example: } ---- -Alternatively, if you use the `@SpringBootTest` annotation with -`WebEnvironment.RANDOM_PORT` or `WebEnvironment.DEFINED_PORT`, you can inject a -fully configured `TestRestTemplate` and start using it. If necessary, additional -customizations can be applied through the `RestTemplateBuilder` bean. Any URLs that do -not specify a host and port automatically connect to the embedded server, as shown in the -following example: +Alternatively, if you use the `@SpringBootTest` annotation with `WebEnvironment.RANDOM_PORT` or `WebEnvironment.DEFINED_PORT`, you can inject a fully configured `TestRestTemplate` and start using it. +If necessary, additional customizations can be applied through the `RestTemplateBuilder` bean. +Any URLs that do not specify a host and port automatically connect to the embedded server, as shown in the following example: [source,java,indent=0] ---- @@ -7996,17 +6707,12 @@ include::{test-examples}/web/client/SampleWebClientTests.java[tag=test] [[boot-features-websockets]] == WebSockets -Spring Boot provides WebSockets auto-configuration for embedded Tomcat, Jetty, and -Undertow. If you deploy a war file to a standalone container, Spring Boot assumes that the -container is responsible for the configuration of its WebSocket support. +Spring Boot provides WebSockets auto-configuration for embedded Tomcat, Jetty, and Undertow. +If you deploy a war file to a standalone container, Spring Boot assumes that the container is responsible for the configuration of its WebSocket support. -Spring Framework provides {spring-reference}web.html#websocket[rich WebSocket support] -for MVC web applications that can be easily accessed through the -`spring-boot-starter-websocket` module. +Spring Framework provides {spring-reference}web.html#websocket[rich WebSocket support] for MVC web applications that can be easily accessed through the `spring-boot-starter-websocket` module. -WebSocket support is also available for -{spring-reference}web-reactive.html#webflux-websocket[reactive web applications] and -requires to include the WebSocket API alongside `spring-boot-starter-webflux`: +WebSocket support is also available for {spring-reference}web-reactive.html#webflux-websocket[reactive web applications] and requires to include the WebSocket API alongside `spring-boot-starter-webflux`: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -8020,15 +6726,12 @@ requires to include the WebSocket API alongside `spring-boot-starter-webflux`: [[boot-features-webservices]] == Web Services -Spring Boot provides Web Services auto-configuration so that all you must do is define -your `Endpoints`. +Spring Boot provides Web Services auto-configuration so that all you must do is define your `Endpoints`. -The {spring-webservices-reference}[Spring Web Services features] can be easily accessed -with the `spring-boot-starter-webservices` module. +The {spring-webservices-reference}[Spring Web Services features] can be easily accessed with the `spring-boot-starter-webservices` module. -`SimpleWsdl11Definition` and `SimpleXsdSchema` beans can be automatically created for -your WSDLs and XSDs respectively. To do so, configure their location, as shown in the -following example: +`SimpleWsdl11Definition` and `SimpleXsdSchema` beans can be automatically created for your WSDLs and XSDs respectively. +To do so, configure their location, as shown in the following example: [source,properties,indent=0] @@ -8040,12 +6743,9 @@ following example: [[boot-features-webservices-template]] === Calling Web Services with `WebServiceTemplate` -If you need to call remote Web services from your application, you can use the -{spring-webservices-reference}#client-web-service-template[`WebServiceTemplate`] class. -Since `WebServiceTemplate` instances often need to be customized before being used, Spring -Boot does not provide any single auto-configured `WebServiceTemplate` bean. It does, -however, auto-configure a `WebServiceTemplateBuilder`, which can be used to create -`WebServiceTemplate` instances when needed. +If you need to call remote Web services from your application, you can use the {spring-webservices-reference}#client-web-service-template[`WebServiceTemplate`] class. +Since `WebServiceTemplate` instances often need to be customized before being used, Spring Boot does not provide any single auto-configured `WebServiceTemplate` bean. +It does, however, auto-configure a `WebServiceTemplateBuilder`, which can be used to create `WebServiceTemplate` instances when needed. The following code shows a typical example: @@ -8068,9 +6768,8 @@ The following code shows a typical example: } ---- -By default, `WebServiceTemplateBuilder` detects a suitable HTTP-based -`WebServiceMessageSender` using the available HTTP client libraries on the classpath. You -can also customize read and connection timeouts as follows: +By default, `WebServiceTemplateBuilder` detects a suitable HTTP-based `WebServiceMessageSender` using the available HTTP client libraries on the classpath. +You can also customize read and connection timeouts as follows: [source,java,indent=0] ---- @@ -8085,42 +6784,31 @@ can also customize read and connection timeouts as follows: [[boot-features-developing-auto-configuration]] == Creating Your Own Auto-configuration -If you work in a company that develops shared libraries, or if you work on an open-source -or commercial library, you might want to develop your own auto-configuration. -Auto-configuration classes can be bundled in external jars and still be picked-up by -Spring Boot. +If you work in a company that develops shared libraries, or if you work on an open-source or commercial library, you might want to develop your own auto-configuration. +Auto-configuration classes can be bundled in external jars and still be picked-up by Spring Boot. -Auto-configuration can be associated to a "`starter`" that provides the auto-configuration -code as well as the typical libraries that you would use with it. We first cover what -you need to know to build your own auto-configuration and then we move on to the -<>. +Auto-configuration can be associated to a "`starter`" that provides the auto-configuration code as well as the typical libraries that you would use with it. +We first cover what you need to know to build your own auto-configuration and then we move on to the <>. -TIP: A https://github.com/snicoll-demos/spring-boot-master-auto-configuration[demo -project] is available to showcase how you can create a starter step-by-step. +TIP: A https://github.com/snicoll-demos/spring-boot-master-auto-configuration[demo project] is available to showcase how you can create a starter step-by-step. [[boot-features-understanding-auto-configured-beans]] === Understanding Auto-configured Beans Under the hood, auto-configuration is implemented with standard `@Configuration` classes. -Additional `@Conditional` annotations are used to constrain when the auto-configuration -should apply. Usually, auto-configuration classes use `@ConditionalOnClass` and -`@ConditionalOnMissingBean` annotations. This ensures that auto-configuration applies -only when relevant classes are found and when you have not declared your own -`@Configuration`. +Additional `@Conditional` annotations are used to constrain when the auto-configuration should apply. +Usually, auto-configuration classes use `@ConditionalOnClass` and `@ConditionalOnMissingBean` annotations. +This ensures that auto-configuration applies only when relevant classes are found and when you have not declared your own `@Configuration`. -You can browse the source code of {sc-spring-boot-autoconfigure}[`spring-boot-autoconfigure`] -to see the `@Configuration` classes that Spring provides (see the -{github-code}/spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/spring.factories[`META-INF/spring.factories`] -file). +You can browse the source code of {sc-spring-boot-autoconfigure}[`spring-boot-autoconfigure`] to see the `@Configuration` classes that Spring provides (see the {github-code}/spring-boot-project/spring-boot-autoconfigure/src/main/resources/META-INF/spring.factories[`META-INF/spring.factories`] file). [[boot-features-locating-auto-configuration-candidates]] === Locating Auto-configuration Candidates -Spring Boot checks for the presence of a `META-INF/spring.factories` file within your -published jar. The file should list your configuration classes under the -`EnableAutoConfiguration` key, as shown in the following example: +Spring Boot checks for the presence of a `META-INF/spring.factories` file within your published jar. +The file should list your configuration classes under the `EnableAutoConfiguration` key, as shown in the following example: [indent=0] ---- @@ -8129,38 +6817,26 @@ published jar. The file should list your configuration classes under the com.mycorp.libx.autoconfigure.LibXWebAutoConfiguration ---- -[NOTE] -==== -Auto-configurations must be loaded that way _only_. Make sure that they are defined in -a specific package space and that they are never the target of component scanning. -Furthermore, auto-configuration classes should not enable component scanning to find -additional components. Specific ``@Import``s should be used instead. -==== +NOTE: Auto-configurations must be loaded that way _only_. +Make sure that they are defined in a specific package space and that they are never the target of component scanning. +Furthermore, auto-configuration classes should not enable component scanning to find additional components. +Specific ``@Import``s should be used instead. -You can use the -{sc-spring-boot-autoconfigure}/AutoConfigureAfter.{sc-ext}[`@AutoConfigureAfter`] or -{sc-spring-boot-autoconfigure}/AutoConfigureBefore.{sc-ext}[`@AutoConfigureBefore`] -annotations if your configuration needs to be applied in a specific order. For example, -if you provide web-specific configuration, your class may need to be applied after -`WebMvcAutoConfiguration`. +You can use the {sc-spring-boot-autoconfigure}/AutoConfigureAfter.{sc-ext}[`@AutoConfigureAfter`] or {sc-spring-boot-autoconfigure}/AutoConfigureBefore.{sc-ext}[`@AutoConfigureBefore`] annotations if your configuration needs to be applied in a specific order. +For example, if you provide web-specific configuration, your class may need to be applied after `WebMvcAutoConfiguration`. -If you want to order certain auto-configurations that should not have any direct -knowledge of each other, you can also use `@AutoConfigureOrder`. That annotation has the -same semantic as the regular `@Order` annotation but provides a dedicated order for -auto-configuration classes. +If you want to order certain auto-configurations that should not have any direct knowledge of each other, you can also use `@AutoConfigureOrder`. +That annotation has the same semantic as the regular `@Order` annotation but provides a dedicated order for auto-configuration classes. [[boot-features-condition-annotations]] === Condition Annotations -You almost always want to include one or more `@Conditional` annotations on your -auto-configuration class. The `@ConditionalOnMissingBean` annotation is one common -example that is used to allow developers to override auto-configuration if they are -not happy with your defaults. +You almost always want to include one or more `@Conditional` annotations on your auto-configuration class. +The `@ConditionalOnMissingBean` annotation is one common example that is used to allow developers to override auto-configuration if they are not happy with your defaults. -Spring Boot includes a number of `@Conditional` annotations that you can reuse in your -own code by annotating `@Configuration` classes or individual `@Bean` methods. These -annotations include: +Spring Boot includes a number of `@Conditional` annotations that you can reuse in your own code by annotating `@Configuration` classes or individual `@Bean` methods. +These annotations include: * <> * <> @@ -8170,22 +6846,16 @@ annotations include: * <> + [[boot-features-class-conditions]] ==== Class Conditions -The `@ConditionalOnClass` and `@ConditionalOnMissingClass` annotations let -`@Configuration` classes be included based on the presence or absence of specific classes. -Due to the fact that annotation metadata is parsed by using https://asm.ow2.org/[ASM], you -can use the `value` attribute to refer to the real class, even though that class might not -actually appear on the running application classpath. You can also use the `name` -attribute if you prefer to specify the class name by using a `String` value. +The `@ConditionalOnClass` and `@ConditionalOnMissingClass` annotations let `@Configuration` classes be included based on the presence or absence of specific classes. +Due to the fact that annotation metadata is parsed by using https://asm.ow2.org/[ASM], you can use the `value` attribute to refer to the real class, even though that class might not actually appear on the running application classpath. +You can also use the `name` attribute if you prefer to specify the class name by using a `String` value. -This mechanism does not apply the same way to `@Bean` methods where typically the return -type is the target of the condition: before the condition on the method applies, the JVM -will have loaded the class and potentially processed method references which will fail if -the class is not present. +This mechanism does not apply the same way to `@Bean` methods where typically the return type is the target of the condition: before the condition on the method applies, the JVM will have loaded the class and potentially processed method references which will fail if the class is not present. -To handle this scenario, a separate `@Configuration` class can be used to isolate the -condition, as shown in the following example: +To handle this scenario, a separate `@Configuration` class can be used to isolate the condition, as shown in the following example: [source,java,indent=0] ---- @@ -8208,25 +6878,17 @@ condition, as shown in the following example: } ---- -[TIP] -==== -If you use `@ConditionalOnClass` or `@ConditionalOnMissingClass` as a part of a -meta-annotation to compose your own composed annotations, you must use `name` as referring -to the class in such a case is not handled. -==== +TIP: If you use `@ConditionalOnClass` or `@ConditionalOnMissingClass` as a part of a meta-annotation to compose your own composed annotations, you must use `name` as referring to the class in such a case is not handled. [[boot-features-bean-conditions]] ==== Bean Conditions -The `@ConditionalOnBean` and `@ConditionalOnMissingBean` annotations let a bean be -included based on the presence or absence of specific beans. You can use the `value` -attribute to specify beans by type or `name` to specify beans by name. The `search` -attribute lets you limit the `ApplicationContext` hierarchy that should be considered -when searching for beans. +The `@ConditionalOnBean` and `@ConditionalOnMissingBean` annotations let a bean be included based on the presence or absence of specific beans. +You can use the `value` attribute to specify beans by type or `name` to specify beans by name. +The `search` attribute lets you limit the `ApplicationContext` hierarchy that should be considered when searching for beans. -When placed on a `@Bean` method, the target type defaults to the return type of the -method, as shown in the following example: +When placed on a `@Bean` method, the target type defaults to the return type of the method, as shown in the following example: [source,java,indent=0] ---- @@ -8240,98 +6902,80 @@ method, as shown in the following example: } ---- -In the preceding example, the `myService` bean is going to be created if no bean of type -`MyService` is already contained in the `ApplicationContext`. +In the preceding example, the `myService` bean is going to be created if no bean of type `MyService` is already contained in the `ApplicationContext`. -TIP: You need to be very careful about the order in which bean definitions are added, as -these conditions are evaluated based on what has been processed so far. For this reason, -we recommend using only `@ConditionalOnBean` and `@ConditionalOnMissingBean` annotations -on auto-configuration classes (since these are guaranteed to load after any user-defined -bean definitions have been added). +TIP: You need to be very careful about the order in which bean definitions are added, as these conditions are evaluated based on what has been processed so far. +For this reason, we recommend using only `@ConditionalOnBean` and `@ConditionalOnMissingBean` annotations on auto-configuration classes (since these are guaranteed to load after any user-defined bean definitions have been added). -NOTE: `@ConditionalOnBean` and `@ConditionalOnMissingBean` do not prevent `@Configuration` -classes from being created. The only difference between using these conditions at the class level -and marking each contained `@Bean` method with the annotation is that the former prevents -registration of the `@Configuration` class as a bean if the condition does not match. +NOTE: `@ConditionalOnBean` and `@ConditionalOnMissingBean` do not prevent `@Configuration` classes from being created. +The only difference between using these conditions at the class level and marking each contained `@Bean` method with the annotation is that the former prevents registration of the `@Configuration` class as a bean if the condition does not match. [[boot-features-property-conditions]] ==== Property Conditions -The `@ConditionalOnProperty` annotation lets configuration be included based on a Spring -Environment property. Use the `prefix` and `name` attributes to specify the property that -should be checked. By default, any property that exists and is not equal to `false` is -matched. You can also create more advanced checks by using the `havingValue` and -`matchIfMissing` attributes. +The `@ConditionalOnProperty` annotation lets configuration be included based on a Spring Environment property. +Use the `prefix` and `name` attributes to specify the property that should be checked. +By default, any property that exists and is not equal to `false` is matched. +You can also create more advanced checks by using the `havingValue` and `matchIfMissing` attributes. [[boot-features-resource-conditions]] ==== Resource Conditions -The `@ConditionalOnResource` annotation lets configuration be included only when a -specific resource is present. Resources can be specified by using the usual Spring -conventions, as shown in the following example: `file:/home/user/test.dat`. +The `@ConditionalOnResource` annotation lets configuration be included only when a specific resource is present. +Resources can be specified by using the usual Spring conventions, as shown in the following example: `file:/home/user/test.dat`. [[boot-features-web-application-conditions]] ==== Web Application Conditions -The `@ConditionalOnWebApplication` and `@ConditionalOnNotWebApplication` annotations let -configuration be included depending on whether the application is a "`web application`". -A web application is any application that uses a Spring `WebApplicationContext`, -defines a `session` scope, or has a `StandardServletEnvironment`. +The `@ConditionalOnWebApplication` and `@ConditionalOnNotWebApplication` annotations let configuration be included depending on whether the application is a "`web application`". +A web application is any application that uses a Spring `WebApplicationContext`, defines a `session` scope, or has a `StandardServletEnvironment`. [[boot-features-spel-conditions]] ==== SpEL Expression Conditions -The `@ConditionalOnExpression` annotation lets configuration be included based on the -result of a {spring-reference}core.html#expressions[SpEL expression]. +The `@ConditionalOnExpression` annotation lets configuration be included based on the result of a {spring-reference}core.html#expressions[SpEL expression]. [[boot-features-test-autoconfig]] === Testing your Auto-configuration -An auto-configuration can be affected by many factors: user configuration (`@Bean` -definition and `Environment` customization), condition evaluation (presence of a -particular library), and others. Concretely, each test should create a well defined -`ApplicationContext` that represents a combination of those customizations. +An auto-configuration can be affected by many factors: user configuration (`@Bean` definition and `Environment` customization), condition evaluation (presence of a particular library), and others. +Concretely, each test should create a well defined `ApplicationContext` that represents a combination of those customizations. `ApplicationContextRunner` provides a great way to achieve that. -`ApplicationContextRunner` is usually defined as a field of the test class to gather the -base, common configuration. The following example makes sure that -`UserServiceAutoConfiguration` is always invoked: +`ApplicationContextRunner` is usually defined as a field of the test class to gather the base, common configuration. +The following example makes sure that `UserServiceAutoConfiguration` is always invoked: [source,java,indent=0] ---- include::{test-examples}/autoconfigure/UserServiceAutoConfigurationTests.java[tag=runner] ---- -TIP: If multiple auto-configurations have to be defined, there is no need to order their -declarations as they are invoked in the exact same order as when running the -application. +TIP: If multiple auto-configurations have to be defined, there is no need to order their declarations as they are invoked in the exact same order as when running the application. -Each test can use the runner to represent a particular use case. For instance, the sample -below invokes a user configuration (`UserConfiguration`) and checks that the -auto-configuration backs off properly. Invoking `run` provides a callback context that can -be used with `Assert4J`. +Each test can use the runner to represent a particular use case. +For instance, the sample below invokes a user configuration (`UserConfiguration`) and checks that the auto-configuration backs off properly. +Invoking `run` provides a callback context that can be used with `Assert4J`. [source,java,indent=0] ---- include::{test-examples}/autoconfigure/UserServiceAutoConfigurationTests.java[tag=test-user-config] ---- -It is also possible to easily customize the `Environment`, as shown in the following -example: +It is also possible to easily customize the `Environment`, as shown in the following example: [source,java,indent=0] ---- include::{test-examples}/autoconfigure/UserServiceAutoConfigurationTests.java[tag=test-env] ---- -The runner can also be used to display the `ConditionEvaluationReport`. The report can be printed -at `INFO` or `DEBUG` level. The following example shows how to use the `ConditionEvaluationReportLoggingListener` -to print the report in auto-configuration tests. +The runner can also be used to display the `ConditionEvaluationReport`. +The report can be printed at `INFO` or `DEBUG` level. +The following example shows how to use the `ConditionEvaluationReportLoggingListener` to print the report in auto-configuration tests. [source,java,indent=0] ---- @@ -8349,17 +6993,14 @@ to print the report in auto-configuration tests. ==== Simulating a Web Context -If you need to test an auto-configuration that only operates in a Servlet or Reactive web -application context, use the `WebApplicationContextRunner` or -`ReactiveWebApplicationContextRunner` respectively. +If you need to test an auto-configuration that only operates in a Servlet or Reactive web application context, use the `WebApplicationContextRunner` or `ReactiveWebApplicationContextRunner` respectively. ==== Overriding the Classpath -It is also possible to test what happens when a particular class and/or package is not -present at runtime. Spring Boot ships with a `FilteredClassLoader` that can easily be used -by the runner. In the following example, we assert that if `UserService` is not present, the -auto-configuration is properly disabled: +It is also possible to test what happens when a particular class and/or package is not present at runtime. +Spring Boot ships with a `FilteredClassLoader` that can easily be used by the runner. +In the following example, we assert that if `UserService` is not present, the auto-configuration is properly disabled: [source,java,indent=0] ---- @@ -8373,38 +7014,33 @@ include::{test-examples}/autoconfigure/UserServiceAutoConfigurationTests.java[ta A full Spring Boot starter for a library may contain the following components: * The `autoconfigure` module that contains the auto-configuration code. -* The `starter` module that provides a dependency to the `autoconfigure` module as well -as the library and any additional dependencies that are typically useful. In a nutshell, -adding the starter should provide everything needed to start using that library. +* The `starter` module that provides a dependency to the `autoconfigure` module as well as the library and any additional dependencies that are typically useful. +In a nutshell, adding the starter should provide everything needed to start using that library. -TIP: You may combine the auto-configuration code and the dependency management in a -single module if you do not need to separate those two concerns. +TIP: You may combine the auto-configuration code and the dependency management in a single module if you do not need to separate those two concerns. [[boot-features-custom-starter-naming]] ==== Naming -You should make sure to provide a proper namespace for your starter. Do not start your -module names with `spring-boot`, even if you use a different Maven `groupId`. We may -offer official support for the thing you auto-configure in the future. +You should make sure to provide a proper namespace for your starter. +Do not start your module names with `spring-boot`, even if you use a different Maven `groupId`. +We may offer official support for the thing you auto-configure in the future. -As a rule of thumb, you should name a combined module after the starter. For example, -assume that you are creating a starter for "acme" and that you name the auto-configure -module `acme-spring-boot-autoconfigure` and the starter `acme-spring-boot-starter`. If -you only have one module that combines the two, name it `acme-spring-boot-starter`. +As a rule of thumb, you should name a combined module after the starter. +For example, assume that you are creating a starter for "acme" and that you name the auto-configure module `acme-spring-boot-autoconfigure` and the starter `acme-spring-boot-starter`. +If you only have one module that combines the two, name it `acme-spring-boot-starter`. [[boot-features-custom-starter-configuration-keys]] ==== Configuration keys -If your starter provides configuration keys, use a unique namespace for them. In -particular, do not include your keys in the namespaces that Spring Boot uses (such as -`server`, `management`, `spring`, and so on). If you use the same namespace, we may modify -these namespaces in the future in ways that break your modules. As a rule of thumb, -prefix all your keys with a namespace that you own (e.g. `acme`). +If your starter provides configuration keys, use a unique namespace for them. +In particular, do not include your keys in the namespaces that Spring Boot uses (such as `server`, `management`, `spring`, and so on). +If you use the same namespace, we may modify these namespaces in the future in ways that break your modules. +As a rule of thumb, prefix all your keys with a namespace that you own (e.g. `acme`). -Make sure that configuration keys are documented by adding field javadoc for each -property, as shown in the following example: +Make sure that configuration keys are documented by adding field javadoc for each property, as shown in the following example: [source,java,indent=0] ---- @@ -8431,36 +7067,26 @@ Here are some rules we follow internally to make sure descriptions are consisten * Do not start the description by "The" or "A". * For `boolean` types, start the description with "Whether" or "Enable". * For collection-based types, start the description with "Comma-separated list" -* Use `java.time.Duration` rather than `long` and describe the default unit if it differs -from milliseconds, e.g. "If a duration suffix is not specified, seconds will be used". -* Do not provide the default value in the description unless it has to be determined at -runtime. +* Use `java.time.Duration` rather than `long` and describe the default unit if it differs from milliseconds, e.g. "If a duration suffix is not specified, seconds will be used". +* Do not provide the default value in the description unless it has to be determined at runtime. -Make sure to -<> so that IDE assistance is available for your keys as well. You may -want to review the generated metadata (`META-INF/spring-configuration-metadata.json`) to -make sure your keys are properly documented. Using your own starter in a compatible IDE is -also a good idea to validate that quality of the metadata. +Make sure to <> so that IDE assistance is available for your keys as well. +You may want to review the generated metadata (`META-INF/spring-configuration-metadata.json`) to make sure your keys are properly documented. +Using your own starter in a compatible IDE is also a good idea to validate that quality of the metadata. [[boot-features-custom-starter-module-autoconfigure]] ==== `autoconfigure` Module -The `autoconfigure` module contains everything that is necessary to get started with the -library. It may also contain configuration key definitions (such as -`@ConfigurationProperties`) and any callback interface that can be used to further -customize how the components are initialized. +The `autoconfigure` module contains everything that is necessary to get started with the library. +It may also contain configuration key definitions (such as `@ConfigurationProperties`) and any callback interface that can be used to further customize how the components are initialized. -TIP: You should mark the dependencies to the library as optional so that you can include -the `autoconfigure` module in your projects more easily. If you do it that way, the -library is not provided and, by default, Spring Boot backs off. +TIP: You should mark the dependencies to the library as optional so that you can include the `autoconfigure` module in your projects more easily. +If you do it that way, the library is not provided and, by default, Spring Boot backs off. -Spring Boot uses an annotation processor to collect the conditions on auto-configurations -in a metadata file (`META-INF/spring-autoconfigure-metadata.properties`). If that file is -present, it is used to eagerly filter auto-configurations that do not match, which will -improve startup time. It is recommended to add the following dependency in a module that -contains auto-configurations: +Spring Boot uses an annotation processor to collect the conditions on auto-configurations in a metadata file (`META-INF/spring-autoconfigure-metadata.properties`). +If that file is present, it is used to eagerly filter auto-configurations that do not match, which will improve startup time. +It is recommended to add the following dependency in a module that contains auto-configurations: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -8471,8 +7097,7 @@ contains auto-configurations: ---- -With Gradle 4.5 and earlier, the dependency should be declared in the `compileOnly` -configuration, as shown in the following example: +With Gradle 4.5 and earlier, the dependency should be declared in the `compileOnly` configuration, as shown in the following example: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -8481,8 +7106,7 @@ configuration, as shown in the following example: } ---- -With Gradle 4.6 and later, the dependency should be declared in the `annotationProcessor` -configuration, as shown in the following example: +With Gradle 4.6 and later, the dependency should be declared in the `annotationProcessor` configuration, as shown in the following example: [source,groovy,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -8495,98 +7119,66 @@ configuration, as shown in the following example: [[boot-features-custom-starter-module-starter]] ==== Starter Module -The starter is really an empty jar. Its only purpose is to provide the necessary -dependencies to work with the library. You can think of it as an opinionated view of what -is required to get started. +The starter is really an empty jar. +Its only purpose is to provide the necessary dependencies to work with the library. +You can think of it as an opinionated view of what is required to get started. -Do not make assumptions about the project in which your starter is added. If the library -you are auto-configuring typically requires other starters, mention them as well. -Providing a proper set of _default_ dependencies may be hard if the number of optional -dependencies is high, as you should avoid including dependencies that are unnecessary for -a typical usage of the library. In other words, you should not include optional -dependencies. +Do not make assumptions about the project in which your starter is added. +If the library you are auto-configuring typically requires other starters, mention them as well. +Providing a proper set of _default_ dependencies may be hard if the number of optional dependencies is high, as you should avoid including dependencies that are unnecessary for a typical usage of the library. +In other words, you should not include optional dependencies. -NOTE: Either way, your starter must reference the core Spring Boot starter -(`spring-boot-starter`) directly or indirectly (i.e. no need to add it if your starter -relies on another starter). If a project is created with only your custom starter, Spring -Boot's core features will be honoured by the presence of the core starter. +NOTE: Either way, your starter must reference the core Spring Boot starter (`spring-boot-starter`) directly or indirectly (i.e. no need to add it if your starter relies on another starter). +If a project is created with only your custom starter, Spring Boot's core features will be honoured by the presence of the core starter. [[boot-features-kotlin]] == Kotlin support -https://kotlinlang.org[Kotlin] is a statically-typed language targeting the JVM (and other -platforms) which allows writing concise and elegant code while providing -{kotlin-documentation}java-interop.html[interoperability] with existing libraries written -in Java. +https://kotlinlang.org[Kotlin] is a statically-typed language targeting the JVM (and other platforms) which allows writing concise and elegant code while providing {kotlin-documentation}java-interop.html[interoperability] with existing libraries written in Java. -Spring Boot provides Kotlin support by leveraging the support in other Spring projects -such as Spring Framework, Spring Data, and Reactor. See the -{spring-reference}languages.html#kotlin[Spring Framework Kotlin support documentation] -for more information. +Spring Boot provides Kotlin support by leveraging the support in other Spring projects such as Spring Framework, Spring Data, and Reactor. +See the {spring-reference}languages.html#kotlin[Spring Framework Kotlin support documentation] for more information. -The easiest way to start with Spring Boot and Kotlin is to follow -https://spring.io/guides/tutorials/spring-boot-kotlin/[this comprehensive tutorial]. You -can create new Kotlin projects via -https://start.spring.io/#!language=kotlin[start.spring.io]. Feel free to join the #spring -channel of https://slack.kotlinlang.org/[Kotlin Slack] or ask a question with the `spring` -and `kotlin` tags on https://stackoverflow.com/questions/tagged/spring+kotlin[Stack -Overflow] if you need support. +The easiest way to start with Spring Boot and Kotlin is to follow https://spring.io/guides/tutorials/spring-boot-kotlin/[this comprehensive tutorial]. +You can create new Kotlin projects via https://start.spring.io/#!language=kotlin[start.spring.io]. +Feel free to join the #spring channel of https://slack.kotlinlang.org/[Kotlin Slack] or ask a question with the `spring` and `kotlin` tags on https://stackoverflow.com/questions/tagged/spring+kotlin[Stack Overflow] if you need support. [[boot-features-kotlin-requirements]] === Requirements -Spring Boot supports Kotlin 1.2.x. To use Kotlin, `org.jetbrains.kotlin:kotlin-stdlib` and -`org.jetbrains.kotlin:kotlin-reflect` must be present on the classpath. The -`kotlin-stdlib` variants `kotlin-stdlib-jdk7` and `kotlin-stdlib-jdk8` can also be used. +Spring Boot supports Kotlin 1.2.x. To use Kotlin, `org.jetbrains.kotlin:kotlin-stdlib` and `org.jetbrains.kotlin:kotlin-reflect` must be present on the classpath. +The `kotlin-stdlib` variants `kotlin-stdlib-jdk7` and `kotlin-stdlib-jdk8` can also be used. -Since https://discuss.kotlinlang.org/t/classes-final-by-default/166[Kotlin classes are -final by default], you are likely to want to configure -{kotlin-documentation}compiler-plugins.html#spring-support[kotlin-spring] -plugin in order to automatically open Spring-annotated classes so that they can be -proxied. +Since https://discuss.kotlinlang.org/t/classes-final-by-default/166[Kotlin classes are final by default], you are likely to want to configure {kotlin-documentation}compiler-plugins.html#spring-support[kotlin-spring] plugin in order to automatically open Spring-annotated classes so that they can be proxied. -https://github.com/FasterXML/jackson-module-kotlin[Jackson's Kotlin module] is required -for serializing / deserializing JSON data in Kotlin. It is automatically registered when -found on the classpath. A warning message is logged if Jackson and Kotlin are present but -the Jackson Kotlin module is not. +https://github.com/FasterXML/jackson-module-kotlin[Jackson's Kotlin module] is required for serializing / deserializing JSON data in Kotlin. +It is automatically registered when found on the classpath. +A warning message is logged if Jackson and Kotlin are present but the Jackson Kotlin module is not. -TIP: These dependencies and plugins are provided by default if one bootstraps a Kotlin -project on https://start.spring.io/#!language=kotlin[start.spring.io]. +TIP: These dependencies and plugins are provided by default if one bootstraps a Kotlin project on https://start.spring.io/#!language=kotlin[start.spring.io]. [[boot-features-kotlin-null-safety]] === Null-safety -One of Kotlin's key features is {kotlin-documentation}null-safety.html[null-safety]. It -deals with `null` values at compile time rather than deferring the problem to runtime and -encountering a `NullPointerException`. This helps to eliminate a common source of bugs -without paying the cost of wrappers like `Optional`. Kotlin also allows using functional -constructs with nullable values as described in this -https://www.baeldung.com/kotlin-null-safety[comprehensive guide to null-safety in Kotlin]. +One of Kotlin's key features is {kotlin-documentation}null-safety.html[null-safety]. +It deals with `null` values at compile time rather than deferring the problem to runtime and encountering a `NullPointerException`. +This helps to eliminate a common source of bugs without paying the cost of wrappers like `Optional`. +Kotlin also allows using functional constructs with nullable values as described in this https://www.baeldung.com/kotlin-null-safety[comprehensive guide to null-safety in Kotlin]. -Although Java does not allow one to express null-safety in its type system, Spring -Framework, Spring Data, and Reactor now provide null-safety of their API via -tooling-friendly annotations. By default, types from Java APIs used in Kotlin are -recognized as -{kotlin-documentation}java-interop.html#null-safety-and-platform-types[platform types] -for which null-checks are relaxed. -{kotlin-documentation}java-interop.html#jsr-305-support[Kotlin's support for JSR 305 -annotations] combined with nullability annotations provide null-safety for the related -Spring API in Kotlin. +Although Java does not allow one to express null-safety in its type system, Spring Framework, Spring Data, and Reactor now provide null-safety of their API via tooling-friendly annotations. +By default, types from Java APIs used in Kotlin are recognized as {kotlin-documentation}java-interop.html#null-safety-and-platform-types[platform types] for which null-checks are relaxed. +{kotlin-documentation}java-interop.html#jsr-305-support[Kotlin's support for JSR 305 annotations] combined with nullability annotations provide null-safety for the related Spring API in Kotlin. -The JSR 305 checks can be configured by adding the `-Xjsr305` compiler flag with the -following options: `-Xjsr305={strict|warn|ignore}`. The default behavior is the same as -`-Xjsr305=warn`. The `strict` value is required to have null-safety taken in account in -Kotlin types inferred from Spring API but should be used with the knowledge that Spring -API nullability declaration could evolve even between minor releases and more checks may -be added in the future). +The JSR 305 checks can be configured by adding the `-Xjsr305` compiler flag with the following options: `-Xjsr305={strict|warn|ignore}`. +The default behavior is the same as `-Xjsr305=warn`. +The `strict` value is required to have null-safety taken in account in Kotlin types inferred from Spring API but should be used with the knowledge that Spring API nullability declaration could evolve even between minor releases and more checks may be added in the future). -WARNING: Generic type arguments, varargs and array elements nullability are not yet -supported. See https://jira.spring.io/browse/SPR-15942[SPR-15942] for up-to-date -information. Also be aware that Spring Boot's own API is {github-issues}10712[not yet -annotated]. +WARNING: Generic type arguments, varargs and array elements nullability are not yet supported. +See https://jira.spring.io/browse/SPR-15942[SPR-15942] for up-to-date information. +Also be aware that Spring Boot's own API is {github-issues}10712[not yet annotated]. @@ -8597,51 +7189,46 @@ annotated]. [[boot-features-kotlin-api-runapplication]] ==== runApplication -Spring Boot provides an idiomatic way to run an application with -`runApplication(*args)` as shown in the following example: +Spring Boot provides an idiomatic way to run an application with `runApplication(*args)` as shown in the following example: [source,kotlin,indent=0] ---- -import org.springframework.boot.autoconfigure.SpringBootApplication -import org.springframework.boot.runApplication + import org.springframework.boot.autoconfigure.SpringBootApplication + import org.springframework.boot.runApplication -@SpringBootApplication -class MyApplication + @SpringBootApplication + class MyApplication -fun main(args: Array) { - runApplication(*args) -} + fun main(args: Array) { + runApplication(*args) + } ---- -This is a drop-in replacement for -`SpringApplication.run(MyApplication::class.java, *args)`. It also allows customization -of the application as shown in the following example: +This is a drop-in replacement for `SpringApplication.run(MyApplication::class.java, *args)`. +It also allows customization of the application as shown in the following example: [source,kotlin,indent=0] ---- -runApplication(*args) { - setBannerMode(OFF) -} + runApplication(*args) { + setBannerMode(OFF) + } ---- [[boot-features-kotlin-api-extensions]] ==== Extensions -Kotlin {kotlin-documentation}extensions.html[extensions] provide the ability -to extend existing classes with additional functionality. The Spring Boot Kotlin API makes -use of these extensions to add new Kotlin specific conveniences to existing APIs. +Kotlin {kotlin-documentation}extensions.html[extensions] provide the ability to extend existing classes with additional functionality. +The Spring Boot Kotlin API makes use of these extensions to add new Kotlin specific conveniences to existing APIs. -`TestRestTemplate` extensions, similar to those provided by Spring Framework for -`RestOperations` in Spring Framework, are provided. Among other things, the extensions -make it possible to take advantage of Kotlin reified type parameters. +`TestRestTemplate` extensions, similar to those provided by Spring Framework for `RestOperations` in Spring Framework, are provided. +Among other things, the extensions make it possible to take advantage of Kotlin reified type parameters. [[boot-features-kotlin-dependency-management]] === Dependency management -In order to avoid mixing different version of Kotlin dependencies on the classpath, -dependency management of the following Kotlin dependencies is provided: +In order to avoid mixing different version of Kotlin dependencies on the classpath, dependency management of the following Kotlin dependencies is provided: - `kotlin-reflect` - `kotlin-runtime` @@ -8651,17 +7238,14 @@ dependency management of the following Kotlin dependencies is provided: - `kotlin-stdlib-jre7` - `kotlin-stdlib-jre8` -With Maven, the Kotlin version can be customized via the `kotlin.version` property and -plugin management is provided for `kotlin-maven-plugin`. With Gradle, the Spring Boot -plugin automatically aligns the `kotlin.version` with the version of the Kotlin plugin. +With Maven, the Kotlin version can be customized via the `kotlin.version` property and plugin management is provided for `kotlin-maven-plugin`. +With Gradle, the Spring Boot plugin automatically aligns the `kotlin.version` with the version of the Kotlin plugin. [[boot-features-kotlin-configuration-properties]] === `@ConfigurationProperties` -`@ConfigurationProperties` currently only works with `lateinit` or nullable `var` -properties (the former is recommended), since immutable classes initialized by -constructors are {github-issues}8762[not yet supported]. +`@ConfigurationProperties` currently only works with `lateinit` or nullable `var` properties (the former is recommended), since immutable classes initialized by constructors are {github-issues}8762[not yet supported]. [source,kotlin,indent=0] ---- @@ -8685,32 +7269,22 @@ class KotlinExampleProperties { } ---- -TIP: To generate -<> using the annotation processor, {kotlin-documentation}kapt.html[`kapt` should -be configured] with the `spring-boot-configuration-processor` dependency. +TIP: To generate <> using the annotation processor, {kotlin-documentation}kapt.html[`kapt` should be configured] with the `spring-boot-configuration-processor` dependency. + [[boot-features-kotlin-testing]] === Testing -While it is possible to use JUnit 4 (the default provided by `spring-boot-starter-test`) -to test Kotlin code, JUnit 5 is recommended. JUnit 5 enables a test class to be -instantiated once and reused for all of the class's tests. This makes it possible to use -`@BeforeAll` and `@AfterAll` annotations on non-static methods, which is a good fit for -Kotlin. +While it is possible to use JUnit 4 (the default provided by `spring-boot-starter-test`) to test Kotlin code, JUnit 5 is recommended. +JUnit 5 enables a test class to be instantiated once and reused for all of the class's tests. +This makes it possible to use `@BeforeAll` and `@AfterAll` annotations on non-static methods, which is a good fit for Kotlin. -To use JUnit 5, exclude `junit:junit` dependency from `spring-boot-starter-test`, add -JUnit 5 dependencies, and configure the Maven or Gradle plugin accordingly. See the -{junit5-documentation}/#dependency-metadata-junit-jupiter-samples[JUnit 5 -documentation] for more details. You also need to -{junit5-documentation}/#writing-tests-test-instance-lifecycle-changing-default[switch test -instance lifecycle to "per-class"]. +To use JUnit 5, exclude `junit:junit` dependency from `spring-boot-starter-test`, add JUnit 5 dependencies, and configure the Maven or Gradle plugin accordingly. +See the {junit5-documentation}/#dependency-metadata-junit-jupiter-samples[JUnit 5 documentation] for more details. +You also need to {junit5-documentation}/#writing-tests-test-instance-lifecycle-changing-default[switch test instance lifecycle to "per-class"]. -To mock Kotlin classes, https://mockk.io/[MockK] is recommended. If you need the `Mockk` -equivalent of the Mockito specific -<>, you can use https://github.com/Ninja-Squad/springmockk[SpringMockK] which -provides similar `@MockkBean` and `@SpykBean` annotations. +To mock Kotlin classes, https://mockk.io/[MockK] is recommended. +If you need the `Mockk` equivalent of the Mockito specific <>, you can use https://github.com/Ninja-Squad/springmockk[SpringMockK] which provides similar `@MockkBean` and `@SpykBean` annotations. @@ -8737,7 +7311,6 @@ provides similar `@MockkBean` and `@SpykBean` annotations. [[boot-features-kotlin-resources-examples]] ==== Examples - * https://github.com/sdeleuze/spring-boot-kotlin-demo[spring-boot-kotlin-demo]: regular Spring Boot + Spring Data JPA project * https://github.com/mixitconf/mixit[mixit]: Spring Boot 2 + WebFlux + Reactive Spring Data MongoDB * https://github.com/sdeleuze/spring-kotlin-fullstack[spring-kotlin-fullstack]: WebFlux Kotlin fullstack example with Kotlin2js for frontend instead of JavaScript or TypeScript @@ -8748,10 +7321,7 @@ provides similar `@MockkBean` and `@SpykBean` annotations. [[boot-features-whats-next]] == What to Read Next -If you want to learn more about any of the classes discussed in this section, you can -check out the {dc-root}[Spring Boot API documentation] or you can browse the -{github-code}[source code directly]. If you have specific questions, take a look at the -<> section. +If you want to learn more about any of the classes discussed in this section, you can check out the {dc-root}[Spring Boot API documentation] or you can browse the {github-code}[source code directly]. +If you have specific questions, take a look at the <> section. -If you are comfortable with Spring Boot's core features, you can continue on and read -about <>. +If you are comfortable with Spring Boot's core features, you can continue on and read about <>. diff --git a/spring-boot-project/spring-boot-docs/src/main/asciidoc/using-spring-boot.adoc b/spring-boot-project/spring-boot-docs/src/main/asciidoc/using-spring-boot.adoc index b658dd2c29b..82e5a82ab80 100644 --- a/spring-boot-project/spring-boot-docs/src/main/asciidoc/using-spring-boot.adoc +++ b/spring-boot-project/spring-boot-docs/src/main/asciidoc/using-spring-boot.adoc @@ -3,83 +3,61 @@ [partintro] -- -This section goes into more detail about how you should use Spring Boot. It covers topics -such as build systems, auto-configuration, and how to run your applications. We also -cover some Spring Boot best practices. Although there is nothing particularly special -about Spring Boot (it is just another library that you can consume), there are a few -recommendations that, when followed, make your development process a little easier. +This section goes into more detail about how you should use Spring Boot. +It covers topics such as build systems, auto-configuration, and how to run your applications. +We also cover some Spring Boot best practices. +Although there is nothing particularly special about Spring Boot (it is just another library that you can consume), there are a few recommendations that, when followed, make your development process a little easier. -If you are starting out with Spring Boot, you should probably read the -_<>_ guide before diving into this -section. +If you are starting out with Spring Boot, you should probably read the _<>_ guide before diving into this section. -- [[using-boot-build-systems]] == Build Systems -It is strongly recommended that you choose a build system that supports -<> and that can consume -artifacts published to the "`Maven Central`" repository. We would recommend that you -choose Maven or Gradle. It is possible to get Spring Boot to work with other build -systems (Ant, for example), but they are not particularly well supported. +It is strongly recommended that you choose a build system that supports <> and that can consume artifacts published to the "`Maven Central`" repository. +We would recommend that you choose Maven or Gradle. +It is possible to get Spring Boot to work with other build systems (Ant, for example), but they are not particularly well supported. [[using-boot-dependency-management]] === Dependency Management -Each release of Spring Boot provides a curated list of dependencies that it supports. In -practice, you do not need to provide a version for any of these dependencies in your -build configuration, as Spring Boot manages that for you. When you upgrade Spring -Boot itself, these dependencies are upgraded as well in a consistent way. +Each release of Spring Boot provides a curated list of dependencies that it supports. +In practice, you do not need to provide a version for any of these dependencies in your build configuration, as Spring Boot manages that for you. +When you upgrade Spring Boot itself, these dependencies are upgraded as well in a consistent way. -NOTE: You can still specify a version and override Spring Boot's recommendations if you -need to do so. +NOTE: You can still specify a version and override Spring Boot's recommendations if you need to do so. -The curated list contains all the spring modules that you can use with Spring Boot as -well as a refined list of third party libraries. The list is available as a standard -<> -that can be used with both <> and -<>. +The curated list contains all the spring modules that you can use with Spring Boot as well as a refined list of third party libraries. +The list is available as a standard <> that can be used with both <> and <>. -WARNING: Each release of Spring Boot is associated with a base version of the Spring -Framework. We **highly** recommend that you not specify its version. +WARNING: Each release of Spring Boot is associated with a base version of the Spring Framework. We **highly** recommend that you not specify its version. [[using-boot-maven]] === Maven -Maven users can inherit from the `spring-boot-starter-parent` project to obtain sensible -defaults. The parent project provides the following features: +Maven users can inherit from the `spring-boot-starter-parent` project to obtain sensible defaults. +The parent project provides the following features: * Java 1.8 as the default compiler level. * UTF-8 source encoding. -* A <>, inherited from -the spring-boot-dependencies pom, that manages the versions of common dependencies. This -dependency management lets you omit tags for those dependencies when used in -your own pom. -* An execution of the {spring-boot-maven-plugin-site}/repackage-mojo.html[`repackage` -goal] with a `repackage` execution id. -* Sensible -https://maven.apache.org/plugins/maven-resources-plugin/examples/filter.html[resource -filtering]. -* Sensible plugin configuration (https://www.mojohaus.org/exec-maven-plugin/[exec plugin], -https://github.com/ktoso/maven-git-commit-id-plugin[Git commit ID], and -https://maven.apache.org/plugins/maven-shade-plugin/[shade]). -* Sensible resource filtering for `application.properties` and `application.yml` -including profile-specific files (for example, `application-dev.properties` and -`application-dev.yml`) +* A <>, inherited from the spring-boot-dependencies pom, that manages the versions of common dependencies. +This dependency management lets you omit tags for those dependencies when used in your own pom. +* An execution of the {spring-boot-maven-plugin-site}/repackage-mojo.html[`repackage` goal] with a `repackage` execution id. +* Sensible https://maven.apache.org/plugins/maven-resources-plugin/examples/filter.html[resource filtering]. +* Sensible plugin configuration (https://www.mojohaus.org/exec-maven-plugin/[exec plugin], https://github.com/ktoso/maven-git-commit-id-plugin[Git commit ID], and https://maven.apache.org/plugins/maven-shade-plugin/[shade]). +* Sensible resource filtering for `application.properties` and `application.yml` including profile-specific files (for example, `application-dev.properties` and `application-dev.yml`) -Note that, since the `application.properties` and `application.yml` files accept Spring -style placeholders (`${...}`), the Maven filtering is changed to use `@..@` placeholders. +Note that, since the `application.properties` and `application.yml` files accept Spring style placeholders (`${...}`), the Maven filtering is changed to use `@..@` placeholders. (You can override that by setting a Maven property called `resource.delimiter`.) [[using-boot-maven-parent-pom]] ==== Inheriting the Starter Parent -To configure your project to inherit from the `spring-boot-starter-parent`, set the -`parent` as follows: +To configure your project to inherit from the `spring-boot-starter-parent`, set the `parent` as follows: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -94,9 +72,8 @@ To configure your project to inherit from the `spring-boot-starter-parent`, set NOTE: You should need to specify only the Spring Boot version number on this dependency. If you import additional starters, you can safely omit the version number. -With that setup, you can also override individual dependencies by overriding a property -in your own project. For instance, to upgrade to another Spring Data release train, you -would add the following to your `pom.xml`: +With that setup, you can also override individual dependencies by overriding a property in your own project. +For instance, to upgrade to another Spring Data release train, you would add the following to your `pom.xml`: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -105,21 +82,16 @@ would add the following to your `pom.xml`: ---- -TIP: Check the -{github-code}/spring-boot-project/spring-boot-dependencies/pom.xml[`spring-boot-dependencies` pom] -for a list of supported properties. +TIP: Check the {github-code}/spring-boot-project/spring-boot-dependencies/pom.xml[`spring-boot-dependencies` pom] for a list of supported properties. [[using-boot-maven-without-a-parent]] ==== Using Spring Boot without the Parent POM -Not everyone likes inheriting from the `spring-boot-starter-parent` POM. You may have -your own corporate standard parent that you need to use or you may prefer to explicitly -declare all your Maven configuration. +Not everyone likes inheriting from the `spring-boot-starter-parent` POM. +You may have your own corporate standard parent that you need to use or you may prefer to explicitly declare all your Maven configuration. -If you do not want to use the `spring-boot-starter-parent`, you can still keep the -benefit of the dependency management (but not the plugin management) by using a -`scope=import` dependency, as follows: +If you do not want to use the `spring-boot-starter-parent`, you can still keep the benefit of the dependency management (but not the plugin management) by using a `scope=import` dependency, as follows: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -137,11 +109,9 @@ benefit of the dependency management (but not the plugin management) by using a ---- -The preceding sample setup does not let you override individual dependencies by using a -property, as explained above. To achieve the same result, you need to add an entry in the -`dependencyManagement` of your project **before** the `spring-boot-dependencies` entry. -For instance, to upgrade to another Spring Data release train, you could add the -following element to your `pom.xml`: +The preceding sample setup does not let you override individual dependencies by using a property, as explained above. +To achieve the same result, you need to add an entry in the `dependencyManagement` of your project **before** the `spring-boot-dependencies` entry. +For instance, to upgrade to another Spring Data release train, you could add the following element to your `pom.xml`: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -166,16 +136,14 @@ following element to your `pom.xml`: ---- -NOTE: In the preceding example, we specify a _BOM_, but any dependency type can be -overridden in the same way. +NOTE: In the preceding example, we specify a _BOM_, but any dependency type can be overridden in the same way. [[using-boot-maven-plugin]] ==== Using the Spring Boot Maven Plugin -Spring Boot includes a <> that can package the project as an executable jar. Add the plugin to your -`` section if you want to use it, as shown in the following example: +Spring Boot includes a <> that can package the project as an executable jar. +Add the plugin to your `` section if you want to use it, as shown in the following example: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -190,28 +158,25 @@ plugin>> that can package the project as an executable jar. Add the plugin to yo ---- NOTE: If you use the Spring Boot starter parent pom, you need to add only the plugin. -There is no need to configure it unless you want to change the settings defined in the -parent. +There is no need to configure it unless you want to change the settings defined in the parent. [[using-boot-gradle]] === Gradle -To learn about using Spring Boot with Gradle, please refer to the documentation for -Spring Boot's Gradle plugin: +To learn about using Spring Boot with Gradle, please refer to the documentation for Spring Boot's Gradle plugin: -* Reference ({spring-boot-gradle-plugin}/reference/html[HTML] and -{spring-boot-gradle-plugin}/reference/pdf/spring-boot-gradle-plugin-reference.pdf[PDF]) +* Reference ({spring-boot-gradle-plugin}/reference/html[HTML] and {spring-boot-gradle-plugin}/reference/pdf/spring-boot-gradle-plugin-reference.pdf[PDF]) * {spring-boot-gradle-plugin}/api[API] + + [[using-boot-ant]] === Ant -It is possible to build a Spring Boot project using Apache Ant+Ivy. The -`spring-boot-antlib` "`AntLib`" module is also available to help Ant create executable -jars. +It is possible to build a Spring Boot project using Apache Ant+Ivy. +The `spring-boot-antlib` "`AntLib`" module is also available to help Ant create executable jars. -To declare dependencies, a typical `ivy.xml` file looks something like the following -example: +To declare dependencies, a typical `ivy.xml` file looks something like the following example: [source,xml,indent=0] ---- @@ -267,95 +232,72 @@ A typical `build.xml` looks like the following example: ---- -TIP: If you do not want to use the `spring-boot-antlib` module, see the -_<>_ "`How-to`" . +TIP: If you do not want to use the `spring-boot-antlib` module, see the _<>_ "`How-to`" . [[using-boot-starter]] === Starters -Starters are a set of convenient dependency descriptors that you can include in your -application. You get a one-stop shop for all the Spring and related technologies that you -need without having to hunt through sample code and copy-paste loads of dependency -descriptors. For example, if you want to get started using Spring and JPA for database -access, include the `spring-boot-starter-data-jpa` dependency in your project. +Starters are a set of convenient dependency descriptors that you can include in your application. +You get a one-stop shop for all the Spring and related technologies that you need without having to hunt through sample code and copy-paste loads of dependency descriptors. +For example, if you want to get started using Spring and JPA for database access, include the `spring-boot-starter-data-jpa` dependency in your project. -The starters contain a lot of the dependencies that you need to get a project up and -running quickly and with a consistent, supported set of managed transitive dependencies. +The starters contain a lot of the dependencies that you need to get a project up and running quickly and with a consistent, supported set of managed transitive dependencies. .What's in a name **** -All **official** starters follow a similar naming pattern; `+spring-boot-starter-*+`, -where `+*+` is a particular type of application. This naming structure is intended to -help when you need to find a starter. The Maven integration in many IDEs lets you -search dependencies by name. For example, with the appropriate Eclipse or STS plugin -installed, you can press `ctrl-space` in the POM editor and type -"`spring-boot-starter`" for a complete list. +All **official** starters follow a similar naming pattern; `+spring-boot-starter-*+`, where `+*+` is a particular type of application. +This naming structure is intended to help when you need to find a starter. +The Maven integration in many IDEs lets you search dependencies by name. +For example, with the appropriate Eclipse or STS plugin installed, you can press `ctrl-space` in the POM editor and type "`spring-boot-starter`" for a complete list. -As explained in the "`<>`" section, third party starters should not start with `spring-boot`, as it -is reserved for official Spring Boot artifacts. Rather, a third-party starter typically -starts with the name of the project. For example, a third-party starter project called -`thirdpartyproject` would typically be named `thirdpartyproject-spring-boot-starter`. +As explained in the "`<>`" section, third party starters should not start with `spring-boot`, as it is reserved for official Spring Boot artifacts. +Rather, a third-party starter typically starts with the name of the project. +For example, a third-party starter project called `thirdpartyproject` would typically be named `thirdpartyproject-spring-boot-starter`. **** -The following application starters are provided by Spring Boot under the -`org.springframework.boot` group: +The following application starters are provided by Spring Boot under the `org.springframework.boot` group: .Spring Boot application starters include::../../../target/generated-resources/application-starters.adoc[] -In addition to the application starters, the following starters can be used to add -_<>_ features: +In addition to the application starters, the following starters can be used to add _<>_ features: .Spring Boot production starters include::../../../target/generated-resources/production-starters.adoc[] -Finally, Spring Boot also includes the following starters that can be used if you want to -exclude or swap specific technical facets: +Finally, Spring Boot also includes the following starters that can be used if you want to exclude or swap specific technical facets: .Spring Boot technical starters include::../../../target/generated-resources/technical-starters.adoc[] -TIP: For a list of additional community contributed starters, see the -{github-master-code}/spring-boot-project/spring-boot-starters/README.adoc[README file] in -the `spring-boot-starters` module on GitHub. +TIP: For a list of additional community contributed starters, see the {github-master-code}/spring-boot-project/spring-boot-starters/README.adoc[README file] in the `spring-boot-starters` module on GitHub. [[using-boot-structuring-your-code]] == Structuring Your Code -Spring Boot does not require any specific code layout to work. However, there are some -best practices that help. +Spring Boot does not require any specific code layout to work. However, there are some best practices that help. [[using-boot-using-the-default-package]] === Using the "`default`" Package -When a class does not include a `package` declaration, it is considered to be in the -"`default package`". The use of the "`default package`" is generally discouraged and -should be avoided. It can cause particular problems for Spring Boot applications that use -the `@ComponentScan`, `@EntityScan`, or `@SpringBootApplication` annotations, since every -class from every jar is read. +When a class does not include a `package` declaration, it is considered to be in the "`default package`". +The use of the "`default package`" is generally discouraged and should be avoided. +It can cause particular problems for Spring Boot applications that use the `@ComponentScan`, `@EntityScan`, or `@SpringBootApplication` annotations, since every class from every jar is read. -TIP: We recommend that you follow Java's recommended package naming conventions and use a -reversed domain name (for example, `com.example.project`). +TIP: We recommend that you follow Java's recommended package naming conventions and use a reversed domain name (for example, `com.example.project`). [[using-boot-locating-the-main-class]] === Locating the Main Application Class -We generally recommend that you locate your main application class in a root package -above other classes. The <> is often placed on your main class, and it -implicitly defines a base "`search package`" for certain items. For example, if you are -writing a JPA application, the package of the `@SpringBootApplication` annotated class -is used to search for `@Entity` items. Using a root package also allows component -scan to apply only on your project. +We generally recommend that you locate your main application class in a root package above other classes. +The <> is often placed on your main class, and it implicitly defines a base "`search package`" for certain items. +For example, if you are writing a JPA application, the package of the `@SpringBootApplication` annotated class is used to search for `@Entity` items. Using a root package also allows component scan to apply only on your project. -TIP: If you don't want to use `@SpringBootApplication`, the `@EnableAutoConfiguration` -and `@ComponentScan` annotations that it imports defines that behaviour so you can also -use that instead. +TIP: If you don't want to use `@SpringBootApplication`, the `@EnableAutoConfiguration` and `@ComponentScan` annotations that it imports defines that behavior so you can also use that instead. The following listing shows a typical layout: @@ -379,8 +321,7 @@ The following listing shows a typical layout: +- OrderRepository.java ---- -The `Application.java` file would declare the `main` method, along with the basic -`@SpringBootApplication`, as follows: +The `Application.java` file would declare the `main` method, along with the basic `@SpringBootApplication`, as follows: [source,java,indent=0] ---- @@ -403,67 +344,57 @@ The `Application.java` file would declare the `main` method, along with the basi [[using-boot-configuration-classes]] == Configuration Classes -Spring Boot favors Java-based configuration. Although it is possible to use -`SpringApplication` with XML sources, we generally recommend that your primary source be -a single `@Configuration` class. Usually the class that defines the `main` method is a -good candidate as the primary `@Configuration`. +Spring Boot favors Java-based configuration. +Although it is possible to use `SpringApplication` with XML sources, we generally recommend that your primary source be a single `@Configuration` class. +Usually the class that defines the `main` method is a good candidate as the primary `@Configuration`. -TIP: Many Spring configuration examples have been published on the Internet that use XML -configuration. If possible, always try to use the equivalent Java-based configuration. +TIP: Many Spring configuration examples have been published on the Internet that use XML configuration. +If possible, always try to use the equivalent Java-based configuration. Searching for `+Enable*+` annotations can be a good starting point. [[using-boot-importing-configuration]] === Importing Additional Configuration Classes -You need not put all your `@Configuration` into a single class. The `@Import` annotation -can be used to import additional configuration classes. Alternatively, you can use -`@ComponentScan` to automatically pick up all Spring components, including -`@Configuration` classes. +You need not put all your `@Configuration` into a single class. +The `@Import` annotation can be used to import additional configuration classes. +Alternatively, you can use `@ComponentScan` to automatically pick up all Spring components, including `@Configuration` classes. [[using-boot-importing-xml-configuration]] === Importing XML Configuration -If you absolutely must use XML based configuration, we recommend that you still start -with a `@Configuration` class. You can then use an `@ImportResource` annotation to load -XML configuration files. +If you absolutely must use XML based configuration, we recommend that you still start with a `@Configuration` class. +You can then use an `@ImportResource` annotation to load XML configuration files. [[using-boot-auto-configuration]] == Auto-configuration -Spring Boot auto-configuration attempts to automatically configure your Spring -application based on the jar dependencies that you have added. For example, if `HSQLDB` -is on your classpath, and you have not manually configured any database connection beans, -then Spring Boot auto-configures an in-memory database. +Spring Boot auto-configuration attempts to automatically configure your Spring application based on the jar dependencies that you have added. +For example, if `HSQLDB` is on your classpath, and you have not manually configured any database connection beans, then Spring Boot auto-configures an in-memory database. -You need to opt-in to auto-configuration by adding the `@EnableAutoConfiguration` or -`@SpringBootApplication` annotations to one of your `@Configuration` classes. +You need to opt-in to auto-configuration by adding the `@EnableAutoConfiguration` or `@SpringBootApplication` annotations to one of your `@Configuration` classes. -TIP: You should only ever add one `@SpringBootApplication` or `@EnableAutoConfiguration` -annotation. We generally recommend that you add one or the other to your primary -`@Configuration` class only. +TIP: You should only ever add one `@SpringBootApplication` or `@EnableAutoConfiguration` annotation. +We generally recommend that you add one or the other to your primary `@Configuration` class only. [[using-boot-replacing-auto-configuration]] === Gradually Replacing Auto-configuration -Auto-configuration is non-invasive. At any point, you can start to define your own -configuration to replace specific parts of the auto-configuration. For example, if you -add your own `DataSource` bean, the default embedded database support backs away. +Auto-configuration is non-invasive. +At any point, you can start to define your own configuration to replace specific parts of the auto-configuration. +For example, if you add your own `DataSource` bean, the default embedded database support backs away. -If you need to find out what auto-configuration is currently being applied, and why, -start your application with the `--debug` switch. Doing so enables debug logs for a -selection of core loggers and logs a conditions report to the console. +If you need to find out what auto-configuration is currently being applied, and why, start your application with the `--debug` switch. +Doing so enables debug logs for a selection of core loggers and logs a conditions report to the console. [[using-boot-disabling-specific-auto-configuration]] === Disabling Specific Auto-configuration Classes -If you find that specific auto-configuration classes that you do not want are being -applied, you can use the exclude attribute of `@EnableAutoConfiguration` to disable them, -as shown in the following example: +If you find that specific auto-configuration classes that you do not want are being applied, you can use the exclude attribute of `@EnableAutoConfiguration` to disable them, as shown in the following example: [source,java,indent=0] ---- @@ -477,32 +408,25 @@ as shown in the following example: } ---- -If the class is not on the classpath, you can use the `excludeName` attribute of the -annotation and specify the fully qualified name instead. Finally, you can also control -the list of auto-configuration classes to exclude by using the -`spring.autoconfigure.exclude` property. +If the class is not on the classpath, you can use the `excludeName` attribute of the annotation and specify the fully qualified name instead. +Finally, you can also control the list of auto-configuration classes to exclude by using the `spring.autoconfigure.exclude` property. TIP: You can define exclusions both at the annotation level and by using the property. -NOTE: Even though auto-configuration classes are `public`, the only aspect of the class -that is considered public API is the name of the class which can be used for disabling the -auto-configuration. The actual contents of those classes, such as nested configuration classes -or bean methods are for internal use only and we do not recommend using those directly. +NOTE: Even though auto-configuration classes are `public`, the only aspect of the class that is considered public API is the name of the class which can be used for disabling the auto-configuration. +The actual contents of those classes, such as nested configuration classes or bean methods are for internal use only and we do not recommend using those directly. + + [[using-boot-spring-beans-and-dependency-injection]] == Spring Beans and Dependency Injection -You are free to use any of the standard Spring Framework techniques to define your beans -and their injected dependencies. For simplicity, we often find that using -`@ComponentScan` (to find your beans) and using `@Autowired` (to do constructor -injection) works well. +You are free to use any of the standard Spring Framework techniques to define your beans and their injected dependencies. +For simplicity, we often find that using `@ComponentScan` (to find your beans) and using `@Autowired` (to do constructor injection) works well. -If you structure your code as suggested above (locating your application class in a root -package), you can add `@ComponentScan` without any arguments. All of your application -components (`@Component`, `@Service`, `@Repository`, `@Controller` etc.) are -automatically registered as Spring Beans. +If you structure your code as suggested above (locating your application class in a root package), you can add `@ComponentScan` without any arguments. +All of your application components (`@Component`, `@Service`, `@Repository`, `@Controller` etc.) are automatically registered as Spring Beans. -The following example shows a `@Service` Bean that uses constructor injection to obtain a -required `RiskAssessor` bean: +The following example shows a `@Service` Bean that uses constructor injection to obtain a required `RiskAssessor` bean: [source,java,indent=0] ---- @@ -526,8 +450,7 @@ required `RiskAssessor` bean: } ---- -If a bean has one constructor, you can omit the `@Autowired`, as shown in the following -example: +If a bean has one constructor, you can omit the `@Autowired`, as shown in the following example: [source,java,indent=0] ---- @@ -545,28 +468,20 @@ example: } ---- -TIP: Notice how using constructor injection lets the `riskAssessor` field be marked as -`final`, indicating that it cannot be subsequently changed. +TIP: Notice how using constructor injection lets the `riskAssessor` field be marked as `final`, indicating that it cannot be subsequently changed. [[using-boot-using-springbootapplication-annotation]] == Using the @SpringBootApplication Annotation -Many Spring Boot developers like their apps to use auto-configuration, component scan and -be able to define extra configuration on their "application class". A single -`@SpringBootApplication` annotation can be used to enable those three features, that is: +Many Spring Boot developers like their apps to use auto-configuration, component scan and be able to define extra configuration on their "application class". +A single `@SpringBootApplication` annotation can be used to enable those three features, that is: -* `@EnableAutoConfiguration`: enable <> -* `@ComponentScan`: enable `@Component` scan on the package where the application is -located (see <>) -* `@Configuration`: allow to register extra beans in the context or import additional -configuration classes - -The `@SpringBootApplication` annotation is equivalent to using `@Configuration`, -`@EnableAutoConfiguration`, and `@ComponentScan` with their default attributes, as shown -in the following example: +* `@EnableAutoConfiguration`: enable <> +* `@ComponentScan`: enable `@Component` scan on the package where the application is located (see <>) +* `@Configuration`: allow to register extra beans in the context or import additional configuration classes +The `@SpringBootApplication` annotation is equivalent to using `@Configuration`, `@EnableAutoConfiguration`, and `@ComponentScan` with their default attributes, as shown in the following example: [source,java,indent=0] ---- @@ -585,14 +500,12 @@ in the following example: } ---- -NOTE: `@SpringBootApplication` also provides aliases to customize the attributes of -`@EnableAutoConfiguration` and `@ComponentScan`. +NOTE: `@SpringBootApplication` also provides aliases to customize the attributes of `@EnableAutoConfiguration` and `@ComponentScan`. [NOTE] ==== -None of these features are mandatory and you may choose to replace this single annotation -by any of the features that it enables. For instance, you may not want to use component -scan in your application: +None of these features are mandatory and you may choose to replace this single annotation by any of the features that it enables. +For instance, you may not want to use component scan in your application: [source,java,indent=0] ---- @@ -615,48 +528,38 @@ scan in your application: } ---- -In this example, `Application` is just like any other Spring Boot application except that -`@Component`-annotated classes are not detected automatically and the user-defined beans -are imported explicitly (see `@Import`). +In this example, `Application` is just like any other Spring Boot application except that `@Component`-annotated classes are not detected automatically and the user-defined beans are imported explicitly (see `@Import`). ==== [[using-boot-running-your-application]] == Running Your Application -One of the biggest advantages of packaging your application as a jar and using an -embedded HTTP server is that you can run your application as you would any other. -Debugging Spring Boot applications is also easy. You do not need any special IDE plugins -or extensions. +One of the biggest advantages of packaging your application as a jar and using an embedded HTTP server is that you can run your application as you would any other. +Debugging Spring Boot applications is also easy. You do not need any special IDE plugins or extensions. -NOTE: This section only covers jar based packaging. If you choose to package your -application as a war file, you should refer to your server and IDE documentation. +NOTE: This section only covers jar based packaging. If you choose to package your application as a war file, you should refer to your server and IDE documentation. [[using-boot-running-from-an-ide]] === Running from an IDE You can run a Spring Boot application from your IDE as a simple Java application. -However, you first need to import your project. Import steps vary depending on your IDE -and build system. Most IDEs can import Maven projects directly. For example, Eclipse -users can select `Import...` -> `Existing Maven Projects` from the `File` menu. +However, you first need to import your project. +Import steps vary depending on your IDE and build system. +Most IDEs can import Maven projects directly. +For example, Eclipse users can select `Import...` -> `Existing Maven Projects` from the `File` menu. -If you cannot directly import your project into your IDE, you may be able to generate IDE -metadata by using a build plugin. Maven includes plugins for -https://maven.apache.org/plugins/maven-eclipse-plugin/[Eclipse] and -https://maven.apache.org/plugins/maven-idea-plugin/[IDEA]. Gradle offers plugins for -{gradle-user-guide}/userguide.html[various IDEs]. +If you cannot directly import your project into your IDE, you may be able to generate IDE metadata by using a build plugin. Maven includes plugins for https://maven.apache.org/plugins/maven-eclipse-plugin/[Eclipse] and https://maven.apache.org/plugins/maven-idea-plugin/[IDEA]. +Gradle offers plugins for {gradle-user-guide}/userguide.html[various IDEs]. -TIP: If you accidentally run a web application twice, you see a "`Port already in use`" -error. STS users can use the `Relaunch` button rather than the `Run` button to ensure -that any existing instance is closed. +TIP: If you accidentally run a web application twice, you see a "`Port already in use`" error. STS users can use the `Relaunch` button rather than the `Run` button to ensure that any existing instance is closed. [[using-boot-running-as-a-packaged-application]] === Running as a Packaged Application -If you use the Spring Boot Maven or Gradle plugins to create an executable jar, you can -run your application using `java -jar`, as shown in the following example: +If you use the Spring Boot Maven or Gradle plugins to create an executable jar, you can run your application using `java -jar`, as shown in the following example: [indent=0,subs="attributes"] ---- @@ -664,8 +567,7 @@ run your application using `java -jar`, as shown in the following example: ---- It is also possible to run a packaged application with remote debugging support enabled. -Doing so lets you attach a debugger to your packaged application, as shown in the -following example: +Doing so lets you attach a debugger to your packaged application, as shown in the following example: [indent=0,subs="attributes"] ---- @@ -677,8 +579,8 @@ following example: [[using-boot-running-with-the-maven-plugin]] === Using the Maven Plugin -The Spring Boot Maven plugin includes a `run` goal that can be used to quickly compile -and run your application. Applications run in an exploded form, as they do in your IDE. +The Spring Boot Maven plugin includes a `run` goal that can be used to quickly compile and run your application. +Applications run in an exploded form, as they do in your IDE. The following example shows a typical Maven command to run a Spring Boot application: [indent=0,subs="attributes"] @@ -686,8 +588,7 @@ The following example shows a typical Maven command to run a Spring Boot applica $ mvn spring-boot:run ---- -You might also want to use the `MAVEN_OPTS` operating system environment variable, as -shown in the following example: +You might also want to use the `MAVEN_OPTS` operating system environment variable, as shown in the following example: [indent=0,subs="attributes"] ---- @@ -698,17 +599,15 @@ shown in the following example: [[using-boot-running-with-the-gradle-plugin]] === Using the Gradle Plugin -The Spring Boot Gradle plugin also includes a `bootRun` task that can be used to run your -application in an exploded form. The `bootRun` task is added whenever you apply the -`org.springframework.boot` and `java` plugins and is shown in the following example: +The Spring Boot Gradle plugin also includes a `bootRun` task that can be used to run your application in an exploded form. +The `bootRun` task is added whenever you apply the `org.springframework.boot` and `java` plugins and is shown in the following example: [indent=0,subs="attributes"] ---- $ gradle bootRun ---- -You might also want to use the `JAVA_OPTS` operating system environment variable, as -shown in the following example: +You might also want to use the `JAVA_OPTS` operating system environment variable, as shown in the following example: [indent=0,subs="attributes"] ---- @@ -719,25 +618,20 @@ shown in the following example: [[using-boot-hot-swapping]] === Hot Swapping -Since Spring Boot applications are just plain Java applications, JVM hot-swapping should -work out of the box. JVM hot swapping is somewhat limited with the bytecode that it can -replace. For a more complete solution, -https://zeroturnaround.com/software/jrebel/[JRebel] can be used. +Since Spring Boot applications are just plain Java applications, JVM hot-swapping should work out of the box. +JVM hot swapping is somewhat limited with the bytecode that it can replace. +For a more complete solution, https://jrebel.com/software/jrebel/[JRebel] can be used. -The -`spring-boot-devtools` module also includes support for quick application restarts. -See the <> section later in this chapter and the -<> for details. +The `spring-boot-devtools` module also includes support for quick application restarts. +See the <> section later in this chapter and the <> for details. [[using-boot-devtools]] == Developer Tools -Spring Boot includes an additional set of tools that can make the application -development experience a little more pleasant. The `spring-boot-devtools` module can be -included in any project to provide additional development-time features. To include -devtools support, add the module dependency to your build, as shown in the following -listings for Maven and Gradle: +Spring Boot includes an additional set of tools that can make the application development experience a little more pleasant. +The `spring-boot-devtools` module can be included in any project to provide additional development-time features. +To include devtools support, add the module dependency to your build, as shown in the following listings for Maven and Gradle: .Maven [source,xml,indent=0,subs="verbatim,quotes,attributes"] @@ -765,121 +659,90 @@ listings for Maven and Gradle: } ---- -NOTE: Developer tools are automatically disabled when running a fully packaged -application. If your application is launched from `java -jar` or if it is started from a -special classloader, then it is considered a "`production application`". If that does not -apply to you (i.e. if you run your application from a container), consider excluding -devtools or set the `-Dspring.devtools.restart.enabled=false` system property. +NOTE: Developer tools are automatically disabled when running a fully packaged application. +If your application is launched from `java -jar` or if it is started from a special classloader, then it is considered a "`production application`". +If that does not apply to you (i.e. if you run your application from a container), consider excluding devtools or set the `-Dspring.devtools.restart.enabled=false` system property. -TIP: Flagging the dependency as optional in Maven or using a custom`developmentOnly` -configuration in Gradle (as shown above) is a best practice that prevents devtools from -being transitively applied to other modules that use your project. +TIP: Flagging the dependency as optional in Maven or using a custom`developmentOnly` configuration in Gradle (as shown above) is a best practice that prevents devtools from being transitively applied to other modules that use your project. -TIP: Repackaged archives do not contain devtools by default. If you want to use a -<>, you need to disable the -`excludeDevtools` build property to include it. The property is supported with both the -Maven and Gradle plugins. +TIP: Repackaged archives do not contain devtools by default. If you want to use a <>, you need to disable the `excludeDevtools` build property to include it. +The property is supported with both the Maven and Gradle plugins. [[using-boot-devtools-property-defaults]] === Property Defaults -Several of the libraries supported by Spring Boot use caches to improve performance. For -example, <> cache compiled templates to avoid repeatedly parsing template files. Also, -Spring MVC can add HTTP caching headers to responses when serving static resources. +Several of the libraries supported by Spring Boot use caches to improve performance. +For example, <> cache compiled templates to avoid repeatedly parsing template files. +Also, Spring MVC can add HTTP caching headers to responses when serving static resources. -While caching is very beneficial in production, it can be counter-productive during -development, preventing you from seeing the changes you just made in your application. +While caching is very beneficial in production, it can be counter-productive during development, preventing you from seeing the changes you just made in your application. For this reason, spring-boot-devtools disables the caching options by default. Cache options are usually configured by settings in your `application.properties` file. -For example, Thymeleaf offers the `spring.thymeleaf.cache` property. Rather than needing -to set these properties manually, the `spring-boot-devtools` module automatically applies -sensible development-time configuration. +For example, Thymeleaf offers the `spring.thymeleaf.cache` property. +Rather than needing to set these properties manually, the `spring-boot-devtools` module automatically applies sensible development-time configuration. -Because you need more information about web requests while developing Spring MVC and -Spring WebFlux applications, developer tools will enable `DEBUG` logging for the `web` -logging group. This will give you information about the incoming request, which handler is -processing it, the response outcome, etc. If you wish to log all request details -(including potentially sensitive information), you can turn on the -`spring.http.log-request-details` configuration property. +Because you need more information about web requests while developing Spring MVC and Spring WebFlux applications, developer tools will enable `DEBUG` logging for the `web` logging group. +This will give you information about the incoming request, which handler is processing it, the response outcome, etc. +If you wish to log all request details (including potentially sensitive information), you can turn on the `spring.http.log-request-details` configuration property. -NOTE: If you don't want property defaults to be applied you can set -`spring.devtools.add-properties` to `false` in your `application.properties`. +NOTE: If you don't want property defaults to be applied you can set `spring.devtools.add-properties` to `false` in your `application.properties`. -TIP: For a complete list of the properties that are applied by the devtools, see -{sc-spring-boot-devtools}/env/DevToolsPropertyDefaultsPostProcessor.{sc-ext}[DevToolsPropertyDefaultsPostProcessor]. +TIP: For a complete list of the properties that are applied by the devtools, see {sc-spring-boot-devtools}/env/DevToolsPropertyDefaultsPostProcessor.{sc-ext}[DevToolsPropertyDefaultsPostProcessor]. [[using-boot-devtools-restart]] === Automatic Restart -Applications that use `spring-boot-devtools` automatically restart whenever files on the -classpath change. This can be a useful feature when working in an IDE, as it gives a very -fast feedback loop for code changes. By default, any entry on the classpath that points -to a folder is monitored for changes. Note that certain resources, such as static assets -and view templates, <>. +Applications that use `spring-boot-devtools` automatically restart whenever files on the classpath change. +This can be a useful feature when working in an IDE, as it gives a very fast feedback loop for code changes. +By default, any entry on the classpath that points to a folder is monitored for changes. +Note that certain resources, such as static assets and view templates, <>. .Triggering a restart **** -As DevTools monitors classpath resources, the only way to trigger a restart is to update -the classpath. The way in which you cause the classpath to be updated depends on the IDE -that you are using. In Eclipse, saving a modified file causes the classpath to be updated -and triggers a restart. In IntelliJ IDEA, building the project -(`Build +->+ Build Project`) has the same effect. +As DevTools monitors classpath resources, the only way to trigger a restart is to update the classpath. +The way in which you cause the classpath to be updated depends on the IDE that you are using. +In Eclipse, saving a modified file causes the classpath to be updated and triggers a restart. +In IntelliJ IDEA, building the project (`Build +->+ Build Project`) has the same effect. **** -[NOTE] -==== -As long as forking is enabled, you can also start your application by using the supported -build plugins (Maven and Gradle), since DevTools needs an isolated application -classloader to operate properly. By default, Gradle and Maven do that when they detect -DevTools on the classpath. - -==== +NOTE: As long as forking is enabled, you can also start your application by using the supported build plugins (Maven and Gradle), since DevTools needs an isolated application classloader to operate properly. +By default, Gradle and Maven do that when they detect DevTools on the classpath. TIP: Automatic restart works very well when used with LiveReload. -<> for details. If you use -JRebel, automatic restarts are disabled in favor of dynamic class reloading. Other -devtools features (such as LiveReload and property overrides) can still be used. +<> for details. If you use JRebel, automatic restarts are disabled in favor of dynamic class reloading. +Other devtools features (such as LiveReload and property overrides) can still be used. -NOTE: DevTools relies on the application context's shutdown hook to close it during a -restart. It does not work correctly if you have disabled the shutdown hook -(`SpringApplication.setRegisterShutdownHook(false)`). +NOTE: DevTools relies on the application context's shutdown hook to close it during a restart. +It does not work correctly if you have disabled the shutdown hook (`SpringApplication.setRegisterShutdownHook(false)`). -NOTE: When deciding if an entry on the classpath should trigger a restart when it -changes, DevTools automatically ignores projects named `spring-boot`, -`spring-boot-devtools`, `spring-boot-autoconfigure`, `spring-boot-actuator`, and -`spring-boot-starter`. +NOTE: When deciding if an entry on the classpath should trigger a restart when it changes, DevTools automatically ignores projects named `spring-boot`, `spring-boot-devtools`, `spring-boot-autoconfigure`, `spring-boot-actuator`, and `spring-boot-starter`. NOTE: DevTools needs to customize the `ResourceLoader` used by the `ApplicationContext`. -If your application provides one already, it is going to be wrapped. Direct override of -the `getResource` method on the `ApplicationContext` is not supported. +If your application provides one already, it is going to be wrapped. +Direct override of the `getResource` method on the `ApplicationContext` is not supported. [[using-spring-boot-restart-vs-reload]] .Restart vs Reload **** -The restart technology provided by Spring Boot works by using two classloaders. Classes -that do not change (for example, those from third-party jars) are loaded into a _base_ -classloader. Classes that you are actively developing are loaded into a _restart_ -classloader. When the application is restarted, the _restart_ classloader is thrown away -and a new one is created. This approach means that application restarts are typically -much faster than "`cold starts`", since the _base_ classloader is already available and -populated. +The restart technology provided by Spring Boot works by using two classloaders. +Classes that do not change (for example, those from third-party jars) are loaded into a _base_ classloader. +Classes that you are actively developing are loaded into a _restart_ classloader. +When the application is restarted, the _restart_ classloader is thrown away and a new one is created. +This approach means that application restarts are typically much faster than "`cold starts`", since the _base_ classloader is already available and populated. -If you find that restarts are not quick enough for your applications or you encounter -classloading issues, you could consider reloading technologies such as -https://zeroturnaround.com/software/jrebel/[JRebel] from ZeroTurnaround. These work by -rewriting classes as they are loaded to make them more amenable to reloading. +If you find that restarts are not quick enough for your applications or you encounter classloading issues, you could consider reloading technologies such as https://jrebel.com/software/jrebel/[JRebel] from ZeroTurnaround. +These work by rewriting classes as they are loaded to make them more amenable to reloading. **** + + [[using-boot-devtools-restart-logging-condition-delta]] ==== Logging changes in condition evaluation -By default, each time your application restarts, a report showing the condition evaluation -delta is logged. The report shows the changes to your application's auto-configuration as -you make changes such as adding or removing beans and setting configuration properties. +By default, each time your application restarts, a report showing the condition evaluation delta is logged. +The report shows the changes to your application's auto-configuration as you make changes such as adding or removing beans and setting configuration properties. To disable the logging of the report, set the following property: @@ -891,46 +754,35 @@ To disable the logging of the report, set the following property: [[using-boot-devtools-restart-exclude]] ==== Excluding Resources -Certain resources do not necessarily need to trigger a restart when they are changed. For -example, Thymeleaf templates can be edited in-place. By default, changing resources -in `/META-INF/maven`, `/META-INF/resources`, `/resources`, `/static`, `/public`, or -`/templates` does not trigger a restart but does trigger a -<>. If you want to customize these -exclusions, you can use the `spring.devtools.restart.exclude` property. For example, to -exclude only `/static` and `/public` you would set the following property: +Certain resources do not necessarily need to trigger a restart when they are changed. +For example, Thymeleaf templates can be edited in-place. +By default, changing resources in `/META-INF/maven`, `/META-INF/resources`, `/resources`, `/static`, `/public`, or `/templates` does not trigger a restart but does trigger a <>. +If you want to customize these exclusions, you can use the `spring.devtools.restart.exclude` property. +For example, to exclude only `/static` and `/public` you would set the following property: [indent=0] ---- spring.devtools.restart.exclude=static/**,public/** ---- -TIP: If you want to keep those defaults and _add_ additional exclusions, use the -`spring.devtools.restart.additional-exclude` property instead. +TIP: If you want to keep those defaults and _add_ additional exclusions, use the `spring.devtools.restart.additional-exclude` property instead. + [[using-boot-devtools-restart-additional-paths]] ==== Watching Additional Paths -You may want your application to be restarted or reloaded when you make changes to files -that are not on the classpath. To do so, use the -`spring.devtools.restart.additional-paths` property to configure additional paths to -watch for changes. You can use the `spring.devtools.restart.exclude` property -<> to control whether changes -beneath the additional paths trigger a full restart or a -<>. +You may want your application to be restarted or reloaded when you make changes to files that are not on the classpath. +To do so, use the `spring.devtools.restart.additional-paths` property to configure additional paths to watch for changes. +You can use the `spring.devtools.restart.exclude` property <> to control whether changes beneath the additional paths trigger a full restart or a <>. [[using-boot-devtools-restart-disable]] ==== Disabling Restart -If you do not want to use the restart feature, you can disable it by using the -`spring.devtools.restart.enabled` property. In most cases, you can set this property in -your `application.properties` (doing so still initializes the restart classloader, but it -does not watch for file changes). +If you do not want to use the restart feature, you can disable it by using the `spring.devtools.restart.enabled` property. +In most cases, you can set this property in your `application.properties` (doing so still initializes the restart classloader, but it does not watch for file changes). -If you need to _completely_ disable restart support (for example, because it does not work -with a specific library), you need to set the `spring.devtools.restart.enabled` `System` -property to `false` before calling `SpringApplication.run(...)`, as shown in the -following example: +If you need to _completely_ disable restart support (for example, because it does not work with a specific library), you need to set the `spring.devtools.restart.enabled` `System` property to `false` before calling `SpringApplication.run(...)`, as shown in the following example: [source,java,indent=0] ---- @@ -944,38 +796,30 @@ following example: [[using-boot-devtools-restart-triggerfile]] ==== Using a Trigger File -If you work with an IDE that continuously compiles changed files, you might prefer to -trigger restarts only at specific times. To do so, you can use a "`trigger file`", which -is a special file that must be modified when you want to actually trigger a restart -check. Changing the file only triggers the check and the restart only occurs if -Devtools has detected it has to do something. The trigger file can be updated manually or -with an IDE plugin. +If you work with an IDE that continuously compiles changed files, you might prefer to trigger restarts only at specific times. +To do so, you can use a "`trigger file`", which is a special file that must be modified when you want to actually trigger a restart check. +Changing the file only triggers the check and the restart only occurs if Devtools has detected it has to do something. +The trigger file can be updated manually or with an IDE plugin. -To use a trigger file, set the `spring.devtools.restart.trigger-file` property to the -path of your trigger file. +To use a trigger file, set the `spring.devtools.restart.trigger-file` property to the path of your trigger file. -TIP: You might want to set `spring.devtools.restart.trigger-file` as a -<>, so that all your projects behave -in the same way. +TIP: You might want to set `spring.devtools.restart.trigger-file` as a <>, so that all your projects behave in the same way. [[using-boot-devtools-customizing-classload]] ==== Customizing the Restart Classloader -As described earlier in the <> section, restart -functionality is implemented by using two classloaders. For most applications, this -approach works well. However, it can sometimes cause classloading issues. +As described earlier in the <> section, restart functionality is implemented by using two classloaders. +For most applications, this approach works well. +However, it can sometimes cause classloading issues. -By default, any open project in your IDE is loaded with the "`restart`" classloader, and -any regular `.jar` file is loaded with the "`base`" classloader. If you work on a -multi-module project, and not every module is imported into your IDE, you may need to -customize things. To do so, you can create a `META-INF/spring-devtools.properties` file. +By default, any open project in your IDE is loaded with the "`restart`" classloader, and any regular `.jar` file is loaded with the "`base`" classloader. +If you work on a multi-module project, and not every module is imported into your IDE, you may need to customize things. +To do so, you can create a `META-INF/spring-devtools.properties` file. -The `spring-devtools.properties` file can contain properties prefixed with -`restart.exclude` and `restart.include`. The `include` elements are items that should be -pulled up into the "`restart`" classloader, and the `exclude` elements are items that -should be pushed down into the "`base`" classloader. The value of the property is a regex -pattern that is applied to the classpath, as shown in the following example: +The `spring-devtools.properties` file can contain properties prefixed with `restart.exclude` and `restart.include`. +The `include` elements are items that should be pulled up into the "`restart`" classloader, and the `exclude` elements are items that should be pushed down into the "`base`" classloader. +The value of the property is a regex pattern that is applied to the classpath, as shown in the following example: [source,properties,indent=0] ---- @@ -983,51 +827,40 @@ pattern that is applied to the classpath, as shown in the following example: restart.include.projectcommon=/mycorp-myproj-[\\w\\d-\.]+\.jar ---- -NOTE: All property keys must be unique. As long as a property starts with -`restart.include.` or `restart.exclude.` it is considered. +NOTE: All property keys must be unique. As long as a property starts with `restart.include.` or `restart.exclude.` it is considered. -TIP: All `META-INF/spring-devtools.properties` from the classpath are loaded. You can -package files inside your project, or in the libraries that the project consumes. +TIP: All `META-INF/spring-devtools.properties` from the classpath are loaded. +You can package files inside your project, or in the libraries that the project consumes. [[using-boot-devtools-known-restart-limitations]] ==== Known Limitations -Restart functionality does not work well with objects that are deserialized by using a -standard `ObjectInputStream`. If you need to deserialize data, you may need to use -Spring's `ConfigurableObjectInputStream` in combination with -`Thread.currentThread().getContextClassLoader()`. +Restart functionality does not work well with objects that are deserialized by using a standard `ObjectInputStream`. +If you need to deserialize data, you may need to use Spring's `ConfigurableObjectInputStream` in combination with `Thread.currentThread().getContextClassLoader()`. -Unfortunately, several third-party libraries deserialize without considering the context -classloader. If you find such a problem, you need to request a fix with the original -authors. +Unfortunately, several third-party libraries deserialize without considering the context classloader. +If you find such a problem, you need to request a fix with the original authors. [[using-boot-devtools-livereload]] === LiveReload -The `spring-boot-devtools` module includes an embedded LiveReload server that can be used -to trigger a browser refresh when a resource is changed. LiveReload browser extensions -are freely available for Chrome, Firefox and Safari from -http://livereload.com/extensions/[livereload.com]. +The `spring-boot-devtools` module includes an embedded LiveReload server that can be used to trigger a browser refresh when a resource is changed. +LiveReload browser extensions are freely available for Chrome, Firefox and Safari from http://livereload.com/extensions/[livereload.com]. -If you do not want to start the LiveReload server when your application runs, you can set -the `spring.devtools.livereload.enabled` property to `false`. +If you do not want to start the LiveReload server when your application runs, you can set the `spring.devtools.livereload.enabled` property to `false`. -NOTE: You can only run one LiveReload server at a time. Before starting your application, -ensure that no other LiveReload servers are running. If you start multiple applications -from your IDE, only the first has LiveReload support. +NOTE: You can only run one LiveReload server at a time. Before starting your application, ensure that no other LiveReload servers are running. +If you start multiple applications from your IDE, only the first has LiveReload support. [[using-boot-devtools-globalsettings]] === Global Settings -You can configure global devtools settings by adding a file named -`.spring-boot-devtools.properties` to your `$HOME` folder (note that the filename starts -with "`.`"). Any properties added to this file apply to _all_ Spring Boot applications on -your machine that use devtools. For example, to configure restart to always use a -<>, you would add the following -property: +You can configure global devtools settings by adding a file named `.spring-boot-devtools.properties` to your `$HOME` folder (note that the filename starts with "`.`"). +Any properties added to this file apply to _all_ Spring Boot applications on your machine that use devtools. +For example, to configure restart to always use a <>, you would add the following property: .~/.spring-boot-devtools.properties [source,properties,indent=0] @@ -1035,18 +868,16 @@ property: spring.devtools.reload.trigger-file=.reloadtrigger ---- -NOTE: Profiles activated in `.spring-boot-devtools.properties` will not affect the -loading of <>. +NOTE: Profiles activated in `.spring-boot-devtools.properties` will not affect the loading of <>. [[using-boot-devtools-remote]] === Remote Applications -The Spring Boot developer tools are not limited to local development. You can also -use several features when running applications remotely. Remote support is opt-in. To -enable it, you need to make sure that `devtools` is included in the repackaged archive, -as shown in the following listing: +The Spring Boot developer tools are not limited to local development. +You can also use several features when running applications remotely. +Remote support is opt-in. +To enable it, you need to make sure that `devtools` is included in the repackaged archive, as shown in the following listing: [source,xml,indent=0,subs="verbatim,quotes,attributes"] ---- @@ -1063,39 +894,34 @@ as shown in the following listing: ---- -Then you need to set a `spring.devtools.remote.secret` property, as shown in the -following example: +Then you need to set a `spring.devtools.remote.secret` property, as shown in the following example: [source,properties,indent=0] ---- spring.devtools.remote.secret=mysecret ---- -WARNING: Enabling `spring-boot-devtools` on a remote application is a security risk. You -should never enable support on a production deployment. +WARNING: Enabling `spring-boot-devtools` on a remote application is a security risk. +You should never enable support on a production deployment. -Remote devtools support is provided in two parts: a server-side endpoint that accepts -connections and a client application that you run in your IDE. The server component is -automatically enabled when the `spring.devtools.remote.secret` property is set. The -client component must be launched manually. +Remote devtools support is provided in two parts: a server-side endpoint that accepts connections and a client application that you run in your IDE. +The server component is automatically enabled when the `spring.devtools.remote.secret` property is set. +The client component must be launched manually. ==== Running the Remote Client Application -The remote client application is designed to be run from within your IDE. You need to run -`org.springframework.boot.devtools.RemoteSpringApplication` with the same classpath as -the remote project that you connect to. The application's single required argument is the -remote URL to which it connects. +The remote client application is designed to be run from within your IDE. +You need to run `org.springframework.boot.devtools.RemoteSpringApplication` with the same classpath as the remote project that you connect to. +The application's single required argument is the remote URL to which it connects. -For example, if you are using Eclipse or STS and you have a project named `my-app` that -you have deployed to Cloud Foundry, you would do the following: +For example, if you are using Eclipse or STS and you have a project named `my-app` that you have deployed to Cloud Foundry, you would do the following: * Select `Run Configurations...` from the `Run` menu. * Create a new `Java Application` "`launch configuration`". * Browse for the `my-app` project. * Use `org.springframework.boot.devtools.RemoteSpringApplication` as the main class. -* Add `+++https://myapp.cfapps.io+++` to the `Program arguments` (or whatever your remote -URL is). +* Add `+++https://myapp.cfapps.io+++` to the `Program arguments` (or whatever your remote URL is). A running remote client might resemble the following listing: @@ -1116,47 +942,39 @@ A running remote client might resemble the following listing: 2015-06-10 18:25:07.130 INFO 14938 --- [ main] o.s.b.devtools.RemoteSpringApplication : Started RemoteSpringApplication in 0.74 seconds (JVM running for 1.105) ---- -NOTE: Because the remote client is using the same classpath as the real application it -can directly read application properties. This is how the `spring.devtools.remote.secret` -property is read and passed to the server for authentication. +NOTE: Because the remote client is using the same classpath as the real application it can directly read application properties. +This is how the `spring.devtools.remote.secret` property is read and passed to the server for authentication. -TIP: It is always advisable to use `https://` as the connection protocol, so that traffic -is encrypted and passwords cannot be intercepted. +TIP: It is always advisable to use `https://` as the connection protocol, so that traffic is encrypted and passwords cannot be intercepted. -TIP: If you need to use a proxy to access the remote application, configure the -`spring.devtools.remote.proxy.host` and `spring.devtools.remote.proxy.port` properties. +TIP: If you need to use a proxy to access the remote application, configure the `spring.devtools.remote.proxy.host` and `spring.devtools.remote.proxy.port` properties. [[using-boot-devtools-remote-update]] ==== Remote Update -The remote client monitors your application classpath for changes in the same way as the -<>. Any updated resource is pushed to the -remote application and (_if required_) triggers a restart. This can be helpful if you -iterate on a feature that uses a cloud service that you do not have locally. Generally, -remote updates and restarts are much quicker than a full rebuild and deploy cycle. +The remote client monitors your application classpath for changes in the same way as the <>. +Any updated resource is pushed to the remote application and (_if required_) triggers a restart. +This can be helpful if you iterate on a feature that uses a cloud service that you do not have locally. +Generally, remote updates and restarts are much quicker than a full rebuild and deploy cycle. + +NOTE: Files are only monitored when the remote client is running. +If you change a file before starting the remote client, it is not pushed to the remote server. + -NOTE: Files are only monitored when the remote client is running. If you change a file -before starting the remote client, it is not pushed to the remote server. [[configuring-file-system-watcher]] ==== Configuring File System Watcher -{sc-spring-boot-devtools}/filewatch/FileSystemWatcher.{sc-ext}[FileSystemWatcher] works -by polling the class changes with a certain time interval, and then waiting for a -predefined quiet period to make sure there are no more changes. The changes are then -uploaded to the remote application. On a slower development environment, it may happen -that the quiet period is not enough, and the changes in the classes may be split into batches. +{sc-spring-boot-devtools}/filewatch/FileSystemWatcher.{sc-ext}[FileSystemWatcher] works by polling the class changes with a certain time interval, and then waiting for a predefined quiet period to make sure there are no more changes. +The changes are then uploaded to the remote application. +On a slower development environment, it may happen that the quiet period is not enough, and the changes in the classes may be split into batches. The server is restarted after the first batch of class changes is uploaded. The next batch can’t be sent to the application, since the server is restarting. -This is typically manifested by a warning in the `RemoteSpringApplication` logs about -failing to upload some of the classes, and a consequent retry. But it may also lead to -application code inconsistency and failure to restart after the first batch of changes is -uploaded. +This is typically manifested by a warning in the `RemoteSpringApplication` logs about failing to upload some of the classes, and a consequent retry. +But it may also lead to application code inconsistency and failure to restart after the first batch of changes is uploaded. -If you observe such problems constantly, try increasing the -`spring.devtools.restart.poll-interval` and `spring.devtools.restart.quiet-period` -parameters to the values that fit your development environment: +If you observe such problems constantly, try increasing the `spring.devtools.restart.poll-interval` and `spring.devtools.restart.quiet-period` parameters to the values that fit your development environment: [source,properties,indent=0] ---- @@ -1164,22 +982,21 @@ parameters to the values that fit your development environment: spring.devtools.restart.quiet-period=1s ---- -The monitored classpath folders are now polled every 2 seconds for changes, and a 1 second -quiet period is maintained to make sure there are no additional class changes. +The monitored classpath folders are now polled every 2 seconds for changes, and a 1 second quiet period is maintained to make sure there are no additional class changes. + + [[security-configuration-for-devtools-remote]] ==== Security Configuration for Devtools Remote -If you have Spring Security on the classpath, you may observe HTTP error 401 or 403 in -the logs of the `RemoteSpringApplication`: +If you have Spring Security on the classpath, you may observe HTTP error 401 or 403 in the logs of the `RemoteSpringApplication`: [indent=0,subs="attributes"] ---- Exception in thread "File Watcher" java.lang.IllegalStateException: Unexpected 401 UNAUTHORIZED response uploading class files ---- -The URL for class uploading should be exempted both from the web security and from the -csrf filter. The following example shows how anonymous access to the remote devtools endpoint -can be configured: +The URL for class uploading should be exempted both from the web security and from the csrf filter. +The following example shows how anonymous access to the remote devtools endpoint can be configured: [source,java,indent=0] ---- @@ -1195,27 +1012,23 @@ public class SecurityConfiguration extends WebSecurityConfigurerAdapter { } ---- -NOTE: The above configuration will only affect the remote devtools endpoint. Spring Boot's default -security auto-configuration will still apply to the rest of the application. If the rest -of the application requires custom security, it needs to be configured separately. +NOTE: The above configuration will only affect the remote devtools endpoint. +Spring Boot's default security auto-configuration will still apply to the rest of the application. +If the rest of the application requires custom security, it needs to be configured separately. [[using-boot-packaging-for-production]] == Packaging Your Application for Production -Executable jars can be used for production deployment. As they are self-contained, they -are also ideally suited for cloud-based deployment. +Executable jars can be used for production deployment. +As they are self-contained, they are also ideally suited for cloud-based deployment. -For additional "`production ready`" features, such as health, auditing, and metric REST -or JMX end-points, consider adding `spring-boot-actuator`. See -_<>_ for details. +For additional "`production ready`" features, such as health, auditing, and metric REST or JMX end-points, consider adding `spring-boot-actuator`. +See _<>_ for details. [[using-boot-whats-next]] == What to Read Next -You should now understand how you can use Spring Boot and some best practices that you -should follow. You can now go on to learn about specific -_<>_ in depth, or you could -skip ahead and read about the "`<>`" aspects of Spring Boot. +You should now understand how you can use Spring Boot and some best practices that you should follow. +You can now go on to learn about specific _<>_ in depth, or you could skip ahead and read about the "`<>`" aspects of Spring Boot.