The asynchronous annotation

The simplest thing to make an EJB asynchronous is through the @Asynchronous annotation. If a client calls an EJB marked with this annotation, it must not wait for the result because all the operations of the EJB will work in asynchronous mode. Here's a sample of an asynchronous singleton EJB:

@Singleton
@Asynchronous
publicclass AsyncBean {
privatestaticfinal Logger logger = ...

publicvoid ignoreResult(inta, intb) {
logger.info("it's asynchronous");
      // here you can add an heavy payload!
}

public Future<Integer> longProcessing(inta, intb) {
returnnewAsyncResult<Integer>(a * b);
}
}

In this example, we have two methods--one void and one returning a result. The ignoreResult method will be executed in a few milliseconds despite a large amount of data being loaded. All the loading will be executed in an asynchronous mode.

The longProcessing method returns a javax.ejb.AsyncResult class. This class is a simple implementation of typed Future class that...