As a follow-up of the ApplicationContext Kotlin extensions, close to
the Kotlin functional WebFlux DSL and partially inspired of the
Groovy/Scala bean configuration DSL, this commit introduces a
lightweight Kotlin DSL for functional bean declaration.
It allows declaring beans as following:
beans {
bean<Foo>()
profile("bar") {
bean<Bar>("bar", scope = Scope.PROTOTYPE)
}
environment({ it.activeProfiles.contains("baz") }) {
bean { Baz(it.ref()) }
bean { Baz(it.ref("bar")) }
}
}
Advantages compared to Regular ApplicationContext API are:
- No exposure of low-level ApplicationContext API
- Focused DSL easier to read, but also easier to write with a fewer
entries in the auto-complete
- Declarative syntax instead of functions with verbs like registerBeans
while still allowing programmatic registration of beans if needed
- Such DSL is idiomatic in Kotlin
- No need to have an ApplicationContext instance to write how you
register your beans since beans { } DSL is conceptually a
Consumer<GenericApplicationContext>
This DSL effectively replaces ApplicationContext Kotlin extensions as
the recommended way to register beans in a functional way with Kotlin.
Issue: SPR-15755
This commits extends nullability declarations to the field level, formalizing the interaction between methods and their underlying fields and therefore avoiding any nullability mismatch.
Issue: SPR-15720
This commit introduces LocaleContextResolver interface, which is used
at ServerWebExchange level to resolve Locale, TimeZone and other i18n
related informations.
It follows Spring MVC locale resolution patterns with a few differences:
- Only LocaleContextResolver is supported since LocaleResolver is less
flexible
- Support is implemented in the org.springframework.web.server.i18n
package of spring-web module rather than in spring-webflux in order
to be able to leverage it at ServerWebExchange level
2 implementations are provided:
- FixedLocaleContextResolver
- AcceptHeaderLocaleContextResolver
It can be configured with both functional or annotation-based APIs.
Issue: SPR-15036
This commit also removes nullability from two common spots: ResolvableType.getType() and TargetSource.getTarget(), both of which are never effectively null with any regular implementation. For such scenarios, a non-null empty type/target is the cleaner contract.
Issue: SPR-15540
Beyond just formally declaring the current behavior, this revision actually enforces non-null behavior in selected signatures now, not tolerating null values anymore when not explicitly documented. It also changes some utility methods with historic null-in/null-out tolerance towards enforced non-null return values, making them a proper citizen in non-null assignments.
Some issues are left as to-do: in particular a thorough revision of spring-test, and a few tests with unclear failures (ignored as "TODO: NULLABLE") to be sorted out in a follow-up commit.
Issue: SPR-15540
Defining nullability of some API like EnvironmentCapable
or ConditionContext causes issues in Spring Boot because
in the context where they are used, it is known for sure
they will return non-null values even if their API can in
other context return null values.
It is better in this case for both Java and Kotlin to
not define at all the nullabity of such API.
In practice, this is achieved by removing the package level
@NonNullApi annotation and adding it only on the
relevant classes.
Issue: SPR-15540
This commit introduces 2 new @Nullable and @NonNullApi
annotations that leverage JSR 305 (dormant but available via
Findbugs jsr305 dependency and already used by libraries
like OkHttp) meta-annotations to specify explicitly
null-safety of Spring Framework parameters and return values.
In order to avoid adding too much annotations, the
default is set at package level with @NonNullApi and
@Nullable annotations are added when needed at parameter or
return value level. These annotations are intended to be used
on Spring Framework itself but also by other Spring projects.
@Nullable annotations have been introduced based on Javadoc
and search of patterns like "return null;". It is expected that
nullability of Spring Framework API will be polished with
complementary commits.
In practice, this will make the whole Spring Framework API
null-safe for Kotlin projects (when KT-10942 will be fixed)
since Kotlin will be able to leverage these annotations to
know if a parameter or a return value is nullable or not. But
this is also useful for Java developers as well since IntelliJ
IDEA, for example, also understands these annotations to
generate warnings when unsafe nullable usages are detected.
Issue: SPR-15540
This commit improves `AbstractValueAdaptingCache` to throw a dedicated
exception if `allowNullValues` is `false` and a `null` value is provided
anyway. This avoid a lower-level exception from the cache library that
will miss some context.
Issue: SPR-15173
Put the lambda parameter at the end and use a function
instead of a supplier to be able to register beans like this:
val context = GenericApplicationContext()
context.registerBean(Foo::class)
context.registerBean{ Bar(it.getBean(Foo::class)) }
Issue: SPR-15118
Based on an idea from Mario Arias, we can avoid requiring specifying
explicitly Supplier lambda type in Kotlin API by declaring the supplier
parameter as "crossinline supplier: () -> T" instead of
"supplier: Supplier<T>".
Issue: SPR-15118
This commit further refines 240f254 to also support java.util.Optional
for synchronized cache access (i.e. when the `sync` attribute on
`@Cacheable` is set to `true`).
Issue: SPR-14853
This commit makes sure that the `unregister` order of registered
application contexts has no incidence on the removal of the LiveBeansView
MBean.
Rather than using the last application context's name to compute the
identity of the MBean to remove, the identity is stored when the MBean is
created.
This commit also adds missing tests.
Issue: SPR-14848
String with version 5 the name of Java Platform, Enterprise Edition
changed from J2EE to Java EE. However a lot of the documentation still
uses the term J2EE.
This commit includes the following changes:
* replace J2EE with Java EE where appropriate
This is not a blind search and replace. The following occurrences
remain unchanged:
* references to old J2EE releases, most notably 1.3 and 1.4.
* references to "Expert One-On-One J2EE Design and Development"
* references to "Core J2EE patterns"
* XML namespaces
* package names
Issue: SPR-14811
See gh-1206
In order to simplify configuration for use cases involving @Bean where
only a bean name or aliases are supplied as an attribute, this commit
introduces a new 'value' attribute that is an @AliasFor 'name' in @Bean.
Issue: SPR-14728
This commit adds a "spring-context-indexer" module that can be added to
any project in order to generate an index of candidate components defined
in the project.
`CandidateComponentsIndexer` is a standard annotation processor that
looks for source files with target annotations (typically `@Component`)
and references them in a `META-INF/spring.components` generated file.
Each entry in the index is the fully qualified name of a candidate
component and the comma-separated list of stereotypes that apply to that
candidate. A typical example of a stereotype is `@Component`. If a
project has a `com.example.FooService` annotated with `@Component` the
following `META-INF/spring.components` file is generated at compile time:
```
com.example.FooService=org.springframework.stereotype.Component
```
A new `@Indexed` annotation can be added on any annotation to instructs
the scanner to include a source file that contains that annotation. For
instance, `@Component` is meta-annotated with `@Indexed` now and adding
`@Indexed` to more annotation types will transparently improve the index
with additional information. This also works for interaces or parent
classes: adding `@Indexed` on a `Repository` base interface means that
the indexed can be queried for its implementation by using the fully
qualified name of the `Repository` interface.
The indexer also adds any class or interface that has a type-level
annotation from the `javax` package. This includes obviously JPA
(`@Entity` and related) but also CDI (`@Named`, `@ManagedBean`) and
servlet annotations (i.e. `@WebFilter`). These are meant to handle
cases where a component needs to identify candidates and use classpath
scanning currently.
If a `package-info.java` file exists, the package is registered using
a "package-info" stereotype.
Such files can later be reused by the `ApplicationContext` to avoid
using component scan. A global `CandidateComponentsIndex` can be easily
loaded from the current classpath using `CandidateComponentsIndexLoader`.
The core framework uses such infrastructure in two areas: to retrieve
the candidate `@Component`s and to build a default `PersistenceUnitInfo`.
Rather than scanning the classpath and using ASM to identify candidates,
the index is used if present.
As long as the include filters refer to an annotation that is directly
annotated with `@Indexed` or an assignable type that is directly
annotated with `@Indexed`, the index can be used since a dedicated entry
wil be present for that type. If any other unsupported include filter is
specified, we fallback on classpath scanning.
In case the index is incomplete or cannot be used, The
`spring.index.ignore` system property can be set to `true` or,
alternatively, in a "spring.properties" at the root of the classpath.
Issue: SPR-11890
Commit 240f254 has introduced support for `java.util.Optional` in the
cache abstraction. If such type is present, the contained value is cached
if it is present.
This new feature slightly changed the semantic of `#result` that was
documented up till this commit as the "return value of the method
invocation". This is no longer true as `#result` for `Optional<T>`
refers to the `T` instance and not the `Optional` instance.
This commit clarifies both the javadoc and the documentation.
Issue: SPR-14587
This commit removes `GuavaCache` and support classes. Caffeine supersedes
the caching support in the Google Guava library with an actively maintained
Java 8+ version in standalone form.
As it is the only Guava feature Spring framework integrates with, this
commit removes effectively any reference to Guava.
Issue: SPR-13797
This commit adds a test runtime dependency on log4j 2 for every project
and migrates all log4j.properties files to log4j2-test.xml files.
Issue: SPR-14431
This commit also removes the corresponding deprecated Servlet MVC variant and updates DispatcherServlet.properties to point to RequestMappingHandlerMapping/Adapter by default.
Issue: SPR-14129
Juergen Hoeller
Sebastien Deleuze
Stephane Nicoll
diguage
Andy Clement
Sam Brannen
QBNemo
Grant Hutchins
Ruben Dijkstra
Alexey Nikolaenko
Mario Arias
Kazuki Shimizu
Rossen Stoyanchev
Philippe Marschall
Igor Mukhin
spodgurskiy
nkjackzhang