Question

我有以下驱动程序/主类封装我的Akka程序：

// Groovy pseudo-code
class FizzBuzz {
    ActorSystem actorSystem

    static void main(String[] args) {
        FizzBuzz d = new FizzBuzz()
        d.run()
    }

    void run() {
        Initialize initCmd = new Initialize()
        MasterActor master = actorSystem.get(...)

        // Tells the entire actor system to initialize itself and start doing stuff.
        // ChickenCluckDetector is an actor managed/supervised by MasterActor.
        master.tell(initCmd, ...)
    }

    // Called when a ChickenCluckDetector actor inside the actor system receives
    // a 'Cluck' message.
    void onChickenGoesCluck(Cluck cluck) {
        // Do something
    }
}

以下ChickenCluckDetector演员：

class ChickenCluckDetector extends UntypedActor {
    @Override
    void onReceive(Object message) {
        if(message instanceof Cluck) {
            Cluck cluck = message as Cluck

            // Now, how to pass the message safely/properly to FizzBuzz#onCluck?
        }
    }
}

因此，手头的问题是如何安全/正确地将Cluck消息传递给FizzBuzz#onCluck(Cluck)，生活在演员系统之外？我可以提供对FizzBuzz的{{1}}引用，如下所示：

ChickenCluckDetector

但是我觉得这违反了Akka的最佳实践，并且可能导致各种基于并发的问题，特别是如果只有一个class ChickenCluckDetector extends UntypedActor { FizzBuzz fizzBuzz @Override void onReceive(Object message) { if(message instanceof Cluck) { Cluck cluck = message as Cluck fizzBuzz.onCluck(cluck) } } }（有）非演员/司机和一万名FizzBuzz演员。想法？

Answer 1

如果只有一个FizzBuzz（有）非演员/驱动程序，以及一万个ChickenCluckDetector演员

然后最好为所有这些ChickenCluckDetectors创建一个公共父级。然后，这个父母可以安全地保存对FizzBuzz的引用，从他所有的孩子那里收到cluck并调用onCluck方法。

在演员之外获取消息的一个选择是询问。在Scala中有演员DSL（仅为完整性而添加）。但我相信你的例子中不需要这些。

public class ChickenCluckMaster extends UntypedActor {

    private FizzBuzz fizzBuzz;

    public ChickenCluckMaster(FizzBuzz fizzBuzz) {
        this.fizzBuzz = fizzBuzz;
    }

    public void onReceive(Object message) throws Exception {
        if (message instanceOf CreateDetector) {
            getContext().actorOf(
                Props.create(ChickenCluckDetector.class, getSelf); // Create child
        } else if (message instanceof Cluck) {
            fizzBuzz.onCluck(cluck);
        } else {
            unhandled(message);
        }
    }

}

public class ChickenCluckDetector extends UntypedActor {

    private ActorRef master;

    public ChickenCluckDetector(ActorRef master) {
        this.master = master;
    }

    public void onReceive(Object message) throws Exception { 
        if (message instanceof Cluck) {
            Cluck cluck = (Cluck) message;
            master.tell(cluck, getSelf);
        } else {
            unhandled(message);
        }
    }

}

Akka：在演员系统之外回传？

1 个答案: