oracle.dbtools.plugin.api.di.annotations

Annotation Type Provides

@Retention(value=RUNTIME)
 @Target(value={TYPE,FIELD})
 @RequestScoped
 @Documented
public @interface Provides

Indicates that a class provides one or more services. By default, all the declared interfaces of the class are considered to be services provided by the class. If the class does not implement any interfaces then the service being offered is the class itself.

Classes annotated with Provides are discoverable by the Dependency Injection framework.

If necessary the set of services provided by a type can be explicitly specified using the value() property.

Examples

Type Provides self

 @Provides
 class Foo {
  ...
 }
 

Since Foo does not implement any interfaces then it provides itself as a service.

Type implicitly provides implementation of an interface

 @Provides
 class Foo implements Bar {
  ...
 }
 

Foo provides the service Bar.

Type explicitly provides implementation of an interface

 @Provides({Bar.class})
 class Foo extends AbstractBar {
  ...
 }
 

Foo is a specialization of the AbstractBar superclass that provides the Bar service.

 @Provides
 class Foo extends AbstractBar implements Bar{
  ...
 }
 

An alternate way to express Foo is a specialization of the AbstractBar superclass that provides the Bar service.

Type explicitly provides implementation of an interface, and self

 @Provides({Foo.class,Bar.class}}
 class Foo extends AbstractBar implements Bar{
  ...
 }
 

Foo provides the Bar service and also provides itself as a service.

Scoping

Provides is annotated with the RequestScoped scoping, meaning that a single instance of a type annotated with Provides will be created per scope. RequestScoped types do not need to be thread-safe, as they will only be referenced in a single thread.

If necessary a type can indicate that only a single instance should be created across all scopes by annotating the type with ApplicationScoped. Any such type must be thread-safe as the instance may be referenced across multiple threads. ApplicationScoped types cannot depend on any RequestScoped types.

 @Provides({GlobalService.class}}
 @ApplicationScoped
 class Singleton implements GlobalService{
  ...
 }
 

Author:

cdivilly

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
Class<?>[]	value The list of services this class provides.

Element Detail

value

public abstract Class<?>[] value

The list of services this class provides.

Returns:

the set of services this class provides. If empty then the annotation processor should infer the set of services is the set of interfaces implemented by the service, or if the class implements no services, then the public API of the class becomes the service provided.

Default:

{}