Updated Sep 07, 2009 by limpbizkit
Labels:	Guice21

JSR330

JSR-330 Integration

This documents an experimental, unreleased feature available in Guice SVN only

JSR-330 standardizes annotations like @Inject and the Provider interfaces for Java platforms. It doesn't currently specify how applications are configured, so it has no analog to Guice's modules.

Guice implements a complete JSR-330 injector. This table summarizes the JSR-330 types and their Guice equivalents.

JSR-330 javax.inject	Guice com.google.inject
@Inject	@Inject	Interchangeable, but JSR-330 places additional constraints on injection points. Fields must be non-final. Methods must be non-abstract, return void, and not have type parameters of their own.
@Named	@Named	Not equivalent. Be careful to inject the same `@Named` that you bind.
@Qualifier	@BindingAnnotation	Interchangeable.
@Scope	@ScopeAnnotation	Interchangeable.
@Singleton	@Singleton	Interchangeable.
Provider	Provider	Guice's Provider extends JSR-330's Provider. Use Jsr330.guicify() to convert a JSR-330 provider into a Guice provider.

Best Practices

For now, stick with Guice's annotations and Provider interface.

Mixing JSR-330 and Guice annotations is supported, but discouraged. In particular, using both @Named annotations can be quite clumsy, as it is hard to identify whose @Named is applied to a particular field or parameter. Similarly, using both Provider interfaces can cause difficultly, since they are not interchangeable.