Example of Akka EventBus for Java

Question

Need some advice of how to use EventBus provided by Akka in Java (not Scala!). The documentation on website seems to be incomplete: http://doc.akka.io/docs/akka/2.0.1/java/event-bus.html

As far as I understood, actor should be created to react on specific messages, like:

final ActorSystem actorSystem = ActorSystem.create("ServerEvents");
final ActorRef actor = actorSystem.actorOf(new Props(SeverEventHandler.class));
actorSystem.eventStream().subscribe(actor,ServerMessage.class);

But now it's not clear how to send a message to the event bus.

Can somebody please share some good tutorials/examples/etc?

Answer 1

I think you're just one line short:

final ActorSystem actorSystem = ActorSystem.create("ServerEvents");
final ActorRef actor = actorSystem.actorOf(new Props(SeverEventHandler.class));
actorSystem.eventStream().subscribe(actor,ServerMessage.class);

actorSystem.eventStream().publish(new ServerMessage()); <<== add this

While ServerEventHandler should be something like

public class ServerEventHandler extends UntypedActor {
  @Override
  public void onReceive(final Object message) {
    System.out.println("Got event in thread: " + Thread.currentThread().getName());
    System.out.println("Event: " + message);
  }
}