Showing posts from January 19, 2012

CDI based @Asynchronous alternative

Arguably one of the most convenient things in EJB after declarative transactions is the @Asynchronous annotation. Applying this annotation to a method will cause it to be executed asynchronously when called (the caller does not have to wait for the method to finish executing). The downside of this annotation is that it's only applicable to EJB beans. While EJB beans these days are lightweight and nothing to avoid in general, the fact is that in Java EE 6 and especially Java EE 7 other managed beans, specifically CDI ones, play an increasingly important role. These beans unfortunately can not directly take advantage of the platform provided @Asynchronous. Building such support ourselves in Java EE 7 however is not that difficult. Thanks to the Java 8, and the Interceptors and Concurrency specs it's actually quite simple, but with a small caveat (see below): We'll start with defining the annotation itself: @InterceptorBinding @Target({METHOD}) @Retention(RUNTIME) @In…