Java EE 8 High Performance

CDI asynchronous events

CDI 2.0 introduces the notion of asynchronous events. It is a manner of asynchronously firing an event for the caller. Here is a sample usage:

public class AsyncSender {    private static final Logger log =    Logger.getLogger(AsyncSender.class.getName());    @Inject    private Event<MyEvent> sender;    public void send(final MyEvent event) {        final CompletionStage<MyEvent> cs = sender.fireAsync(event);        cs.thenRun(() -> {        // some post processing once all observers got notified        });    }}

This code snippet sends an asynchronous event, thanks to fireAsync. The interesting part of this API is that it returns CompletionStage, which enables you to chain some logic after the event has notified all the asynchronous observers.

Asynchronous events ...