using guice injection with actor throws null pointer

Question

I\'m getting null pointer exception on the field injection of a server which is started as an akka actor.

Schedular part:

private Ac         


        

Answer 1

There can be other ways, eg, you can put a static injector handle in Boot or Some-Injector-Holder-class, and inject when you create the actor by call the inherited method: preStart ()

public class Retreiver extends UntypedActor {

    private Logger.ALogger log = Logger.of(Retreiver .class);

    @Override
    public void preStart () {
        super.preStart ();
        Boot.injector.injectMembers (this);
        //Some-Injector-holder.injectMembers (this);
    }

    @Inject
    private myDataService dataService;

    @Override
    public void onReceive(Object arg0) throws Exception {

        if (0 != dataService.getDataCount()) {
        ....
        ....
        ....
        }
    }

and also, you can also inject the injector in actor provider to initialize the actor by the injector in a scope of UntypedActorFactory:

public class InjectingActorProvider implements Provider {
    @Inject
    private Injector injector;

    @SuppressWarnings("serial")
    @Override
    public final ActorRef get() {
            Props props = new Props(new UntypedActorFactory() {
                @Override
                public Actor create() {
                    return injector.getInstance(actorClass);
                }
            });

            props = props.withRouter(...);
            props = props.withDispatcher(...);
            actor = system.actorOf(props, actorName);
            return actor;
    }
}