akka-typed: provide Java-Support for accessing the Event-Stream

[domdorn]

At the moment, its quite hard from Java to access the event-stream.
I had to come up with this code to subscribe to events (inside a typed actor):

          ClassTag<ScenarioEvent> classTag = ClassTag$.MODULE$.apply(ScenarioEvent.class);
          ActorRef<ScenarioEvent> scenarioEventToWrapperAdapter =
              ctx.messageAdapter(ScenarioEvent.class, e -> WrappedScenarioEvent.of(e));
          EventStream.Subscribe<ScenarioEvent> subscribe1 =
              new EventStream.Subscribe(scenarioEventToWrapperAdapter, classTag);
          ctx.getSystem().eventStream().tell(subscribe1);

Probably the easiest way to get this working would be to provide a EventStream.Subscribe constructor that accepts a Class<T> instead of a ClassTag<T>

provide a simple Java API to do the same.

[domdorn]

Please ignore.. I just found out EventStream.Subscribe has a constructor for java.. don't know how I could not have seen that one.