Created
August 28, 2012 15:51
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| public class NonContextualInjector<T> { | |
| // Store the injection target. The CDI spec doesn't require an implementation to cache it, so we do | |
| private final InjectionTarget<T> injectionTarget; | |
| // Store a reference to the CDI BeanManager | |
| private final BeanManager beanManager; | |
| /** | |
| * Create an injector for the given class | |
| */ | |
| public NonContextual(BeanManager manager, Class<T> clazz) { | |
| this.beanManager = manager; | |
| // Generate an "Annotated Type" | |
| AnnotatedType<T> type = manager.createAnnotatedType(clazz); | |
| // Generate the InjectionTarget | |
| this.injectionTarget = manager.createInjectionTarget(type); | |
| } | |
| /** | |
| * Create an injector for the given class | |
| */ | |
| public NonContextual(BeanManager manager, AnnotatedType<T> type) { | |
| this.beanManager = manager; | |
| // Generate the InjectionTarget | |
| this.injectionTarget = manager.createInjectionTarget(type); | |
| } | |
| /** | |
| * Create an injector for the given class | |
| */ | |
| public NonContextual(Class<T> clazz) { | |
| this.beanManager = CDI.current().getBeanManager(); | |
| // Generate an "Annotated Type" | |
| AnnotatedType<T> type = manager.createAnnotatedType(clazz); | |
| // Generate the InjectionTarget | |
| this.injectionTarget = manager.createInjectionTarget(type); | |
| } | |
| /** | |
| * Create an injector for the given class | |
| */ | |
| public NonContextual(AnnotatedType<T> type) { | |
| this.beanManager = CDI.current().getBeanManager(); | |
| // Generate the InjectionTarget | |
| this.injectionTarget = manager.createInjectionTarget(type); | |
| } | |
| public Instance<T> newInstance() { | |
| return new Instance<T>(beanManager, injectionTarget); | |
| } | |
| /** | |
| * Represents a non-contextual instance | |
| */ | |
| public static class Instance<T> | |
| { | |
| private final CreationalContext<T> ctx; | |
| private final InjectionTarget<T> injectionTarget; | |
| private T instance; | |
| private boolean disposed = false; | |
| private Instance(BeanManager beanManager, InjectionTarget<T> injectionTarget) { | |
| this.injectionTarget = injectionTarget; | |
| this.ctx = beanManager.createCreationalContext(null); | |
| } | |
| /** | |
| * Get the instance | |
| */ | |
| public T get() { | |
| if (disposed) { | |
| throw new IllegalStateException("Trying to call get() on an already disposed instance"); | |
| } | |
| if (this.instance == null) { | |
| produce(); | |
| inject(); | |
| postConstruct(); | |
| } | |
| return instance; | |
| } | |
| public void destroy() { | |
| if (this.instance == null) { | |
| throw new IllegalStateException("Trying to call destroy() before the instance was created was called"); | |
| } | |
| if (disposed) { | |
| throw new IllegalStateException("Trying to call destroy() on already disposed instance"); | |
| } | |
| preDestroy(); | |
| dispose(); | |
| } | |
| /** | |
| * Create the instance | |
| */ | |
| public Instance<T> produce() { | |
| if (this.instance != null) { | |
| throw new IllegalStateException("Trying to call produce() on already constructed instance"); | |
| } | |
| if (disposed) { | |
| throw new IllegalStateException("Trying to call produce() on an already disposed instance"); | |
| } | |
| this.instance = injectionTarget.produce(ctx); | |
| return this; | |
| } | |
| /** | |
| * Inject the instance | |
| */ | |
| public Instance<T> inject() { | |
| if (this.instance == null) { | |
| throw new IllegalStateException("Trying to call inject() before produce() was called"); | |
| } | |
| if (disposed) { | |
| throw new IllegalStateException("Trying to call inject() on already disposed instance"); | |
| } | |
| injectionTarget.inject(instance, ctx); | |
| return this; | |
| } | |
| /** | |
| * Call the @PostConstruct callback | |
| */ | |
| public Instance<T> postConstruct() { | |
| if (this.instance == null) { | |
| throw new IllegalStateException("Trying to call postConstruct() before produce() was called"); | |
| } | |
| if (disposed) { | |
| throw new IllegalStateException("Trying to call preDestroy() on already disposed instance"); | |
| } | |
| injectionTarget.postConstruct(instance); | |
| return this; | |
| } | |
| /** | |
| * Call the @PreDestroy callback | |
| */ | |
| public Instance<T> preDestroy() { | |
| if (this.instance == null) { | |
| throw new IllegalStateException("Trying to call preDestroy() before produce() was called"); | |
| } | |
| if (disposed) { | |
| throw new IllegalStateException("Trying to call preDestroy() on already disposed instance"); | |
| } | |
| injectionTarget.preDestroy(instance); | |
| return this; | |
| } | |
| /** | |
| * Dispose of the instance, doing any necessary cleanup | |
| */ | |
| public Instance<T> dispose() { | |
| if (this.instance == null) { | |
| throw new IllegalStateException("Trying to call dispose() before produce() was called"); | |
| } | |
| if (disposed) { | |
| throw new IllegalStateException("Trying to call dispose() on already disposed instance"); | |
| } | |
| injectionTarget.dispose(instance); | |
| ctx.release(); | |
| return this; | |
| } | |
| } | |
| } |
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