scala - 无法使用akka java api的UnTypedActorFactory创建 Actor

Question

我正在尝试使用无类型转换工厂创建一个 Actor ，编译进展顺利。但是在运行应用程序时，我收到以下错误。我在配置中遗漏了什么吗？

Java 代码:

MyActor myactor = new MyActor();  //MyActor extends UnTypedActor
ActorSystem system = ActorSystem.create("mynamespace");
ActorRef actor = system.actorOf(new Props(new UntypedActorFactory() {
      public UntypedActor create() {
          return myactor;
      }
  }));

运行时出错:

Caused by: akka.actor.ActorInitializationException: You cannot create an instance of [com.practice.MyActor] explicitly using the constructor (new). You have to use one of the factory methods to create a new actor. Either use: 'val actor = context.actorOf(Props[MyActor])'
(to create a supervised child actor from within an actor), or 'val actor = system.actorOf(Props(new MyActor(..)))' (to create a top level actor from the ActorSystem)

Answer 1

这是因为您正在 ActorSystem 外部创建 MyActor 实例。在工厂内创建 Actor(这就是它的用途;-))，应该没问题。

ActorSystem system = ActorSystem.create("mynamespace");
ActorRef actor = system.actorOf(new Props(new UntypedActorFactory() {
  public UntypedActor create() {
    return new MyActor();
  }
}));

在这种情况下，您甚至不需要工厂，因为您有一个默认构造函数。只需将类作为参数传递给 Props:

system.actorOf(new Props(MyActor.class));