我有一个java对象,它不是一个从actor系统(Actor)中选择actor的actor。可能的是,选定的actor在系统中不存在。如何检查Akka actor是否存在(akka 2.2)?
在Java Api中,对于ActorSelection而言,ask()不存在,所以我无法发送和Identify消息给actor选择并使用响应的发送者。
我试图通过演员选择将消息发送给演员来解决问题,然后对deadletter作出反应。但我没有得到任何死路一条。
如果演员还活着或不存在,我该如何检查ActorSelection?
ActorSystem system = ActorSystem.create("test");
//create test actor
system.actorOf(Props.create(TestActor.class), "testActor");
//add dead letter listener to the system
ActorRef eventBusActor = asys.actorOf(Props.create(EventBusActor.class), "eventbusactor");
system.eventStream().subscribe(eventBusActor, DeadLetter.class);
//This works. The test actor receives the message
ActorSelection a1 = asys.actorSelection("/user/testActor");
a1.tell("hello", ActorRef.noSender());
//This does not work and does not send dead letters
ActorSelection a2 = asys.actorSelection("/user/doesnotexist");
a2.tell("hello", ActorRef.noSender());
//Does not compile, because ask needs an ActorRef as first argument
ActorSelection a3 = asys.actorSelection("/user/test");
Future f = Patterns.ask(a3, new Identify(), 1000);
哎呀,这是一个监督的,谢谢指点出来:https://www.assembla.com/spaces/akka/simple_planner#/ticket: 3532 –