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
Prior to Java 8 it never really made much sense to author integration
tests using interfaces. Consequently, the Spring TestContext Framework
has never supported finding test-related annotations on interfaces in
its search algorithms.
However, Java 8's support for interface default methods introduces new
testing use cases for which it makes sense to declare test
configuration (e.g., @ContextConfiguration, etc.) on an interface
containing default methods instead of on an abstract base class.
This commit ensures that all non-repeatable, class-level test
annotations in the Spring TestContext Framework can now be declared on
test interfaces. The only test annotations that cannot be declared on
interfaces are therefore @Sql and @SqlGroup.
Issue: SPR-14184
It's handy to know in advance whether or not expression that is
passed to CronSequenceGenerator or CronTrigger constructor would
not results in IllegalArgumentException. The only way to do it
now is to try\catch an instance creation but it's kinda ugly.
This commit makes sure to reject an `@EventListener` annotated method
that also uses `@Async`. In such scenario, the method is invoked in a
separate thread and the infrastructure has no handle on the actual reply,
if any.
The documentation has been improved to refer to that scenario.
Issue: SPR-14113
Juergen Hoeller
Stephane Nicoll
Sam Brannen
Igor Mukhin
spodgurskiy
nkjackzhang
Stefan Ferstl
Ruslan Sibgatullin
Johnny Lim