NumberActor.groovy

// the service that will be automatically injected
final NumberService numberService;

@Inject
public NumberActor(@Named("NumberService") NumberService numberService) {
  this.numberService = numberService;
}

@Override
public void onReceive(Object message) throws Exception {
  if (message instanceof GetRandomInteger) {
    GetRandomInteger query = message
    Callable<Integer> op = new Callable<Integer>() {
      @Override
      Integer call() throws Exception {
        return numberService.nextInt(query.max)
      }
    }
    Future<Integer> futureOpResults = Futures.future(op, this.context.dispatcher())
    Patterns.pipe(futureOpResults, context().dispatcher()).to(sender, self)
  } else {
    unhandled(message);
  }
}