tchekai704/src-spring-framework - src-spring-framework - Gitea

Author	SHA1	Message	Date
Juergen Hoeller	54e2d63d6f	Polishing	8 years ago
Juergen Hoeller	5471d6a465	Revised indexer implementation Issue: SPR-11890	8 years ago
Sam Brannen	1af2fbfbbb	Delete unused imports in spring-context-indexer	8 years ago
Stephane Nicoll	dcade06fa0	Support for candidate components index 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	8 years ago