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   * JBoss, Home of Professional Open Source
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The portable extension integration SPI.

A portable extension may integrate with the container by:

  • Providing its own beans, interceptors and decorators to the container
  • Injecting dependencies into its own objects using the dependency injection service
  • Providing a context implementation for a custom scope
  • Augmenting or overriding the annotation-based metadata with metadata from some other source

The BeanManager object

Portable extensions sometimes interact directly with the container via programmatic API call. The interface BeanManager provides operations for obtaining contextual references for beans, along with many other operations of use to portable extensions.

Container lifecycle events

During the application initialization process, the container fires a series of events, allowing portable extensions to integrate with the container initialization process. Observer methods of these events must belong to extensions declared in META-INF/services.

Lifecycle events include BeforeBeanDiscovery, AfterBeanDiscovery, AfterDeploymentValidation and BeforeShutdown.

Interfaces representing enabled beans

The interfaces Bean, Decorator, Interceptor and ObserverMethod define everything the container needs to manage instances of a bean, interceptor, decorator or observer method.

An instance of Bean exists for every enabled bean. A portable extension may add support for new kinds of beans by implementing Bean, observing the event AfterBeanDiscovery event registering beans with the container. An instance of ObserverMethod exists for every observer method of every enabled bean. A portable extension may add observers by implementing ObserverMethod and registering an instance with the container.

A portable extension may be notified of the existence of an enabled bean by observing the container lifecycle event type ProcessBean or one of its subtypes, or of the existence of an observer method of an enabled bean by observing the event type ProcessObserverMethod.

Alternate metadata sources

A portable extension may provide an alternative metadata source, such as configuration by XML.

Annotated and its subtypes allow a portable extension to specify metadata that overrides the annotations that exist on a bean class. The portable extension is responsible for implementing the interfaces, thereby exposing the metadata to the container. The container must use the operations of Annotated and its subinterfaces to discover program element types and annotations, instead of directly calling the Java Reflection API.

A portable extension provides its metadata to the container by observing the event ProcessAnnotatedType and wrapping the AnnotatedType.

Producer and InjectionTarget

<pr>The interfaces Producer and InjectionTarget abstract the basic lifecycle of (contextual or non-contextual) container managed objects, including instantiation and destruction, dependency injection and lifecycle callbacks.

An instance of InjectionTarget may be obtained from the BeanManager, allowing a portable extension to request these container services for objects under the control of the portable extension.

Furthermore, a portable extension may replace the implementation of InjectionTarget or Producer used by the container with its own implementation by observing the events ProcessInjectionTarget or ProcessProducer.

See also:
package javax.enterprise.inject.spi;

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