Spring Profiles provide a way to segregate parts of your application configuration and make it be available only in certain environments.
Any `@Component`, `@Configuration` or `@ConfigurationProperties` can be marked with `@Profile` to limit when it is loaded, as shown in the following example:
NOTE: If `@ConfigurationProperties` beans are registered via `@EnableConfigurationProperties` instead of automatic scanning, the `@Profile` annotation needs to be specified on the `@Configuration` class that has the `@EnableConfigurationProperties` annotation.
In the case where `@ConfigurationProperties` are scanned, `@Profile` can be specified on the `@ConfigurationProperties` class itself.
You can use a configprop: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,yaml,indent=0,configprops,configblocks]
----
spring:
profiles:
active: "dev,hsqldb"
----
You could also specify it on the command line by using the following switch: `--spring.profiles.active=dev,hsqldb`.
[[features.profiles.adding-active-profiles]]
=== Adding Active Profiles
The configprop: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 properties that *add* to the active profiles rather than replace them.
The `SpringApplication` entry point has a Java API for setting additional profiles (that is, on top of those activated by the configprop:spring.profiles.active[] property).
See the `setAdditionalProfiles()` method in {spring-boot-module-api}/SpringApplication.html[SpringApplication].
Profile groups, which are described in the <<features#features.profiles.groups,next section>> can also be used to add active profiles if a given profile is active.
[[features.profiles.groups]]
=== Profile Groups
Occasionally the profiles that you define and use in your application are too fine-grained and become cumbersome to use.
For example, you might have `proddb` and `prodmq` profiles that you use to enable database and messaging features independently.
To help with this, Spring Boot lets you define profile groups.
A profile group allows you to define a logical name for a related group of profiles.
For example, we can create a `production` group that consists of our `proddb` and `prodmq` profiles.
[source,yaml,indent=0,configblocks]
----
spring:
profiles:
group:
production:
- "proddb"
- "prodmq"
----
Our application can now be started using `--spring.profiles.active=production` to active the `production`, `proddb` and `prodmq` profiles in one hit.
Profile-specific variants of both `application.properties` (or `application.yml`) and files referenced through `@ConfigurationProperties` are considered as files and loaded.
See "<<features#features.external-config.files.profile-specific>>" for details.
