我可以创建演员,actorOf并与他们一起看actorFor.我现在想要一些演员id:String,如果它不存在,我希望它被创建.像这样的东西:
def getRCActor(id: String):ActorRef = {
Logger.info("getting actor %s".format(id))
var a = system.actorFor(id)
if(a.isTerminated){
Logger.info("actor is terminated, creating new one")
return system.actorOf(Props[RC], id:String)
}else{
return a
}
}
但这并不isTerminated总是如此,我得到actor name 1 is not unique!了第二次调用的异常.我想我在这里使用了错误的模式.有人可以帮助如何实现这一目标吗？我需要
我应该使用Dispatcher或Router吗？
解决方案 如我所建议的,我使用一个具体的Supervisor来保存地图中可用的actor.可以要求他提供他的一个孩子.
class RCSupervisor extends Actor {
implicit val timeout = Timeout(1 second)
var as = Map.empty[String, ActorRef]
def getRCActor(id: String) = as get id getOrElse {
val c = context actorOf …我有一个java对象,它不是一个使用actorSelection(Path)从actor系统中选择actor的actor.系统中可能存在所选的actor.
在Java Api中,ActorSelection不存在ask(),因此我无法向actor选择发送和识别消息并使用响应的发送者.
我试图通过演员选择向演员发送消息然后对deadletter做出反应来解决问题.但我没有任何动静.
如果演员是活着还是不存在,我如何检查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);
我试图使用Akka actor的层次结构来处理每个用户状态.有一个拥有所有子节点的父actor,并以正确的方式处理get-or-create(参见a1,a2):
class UserActorRegistry extends Actor {
override def Receive = {
case msg@ DoPerUserWork(userId, _) =>
val perUserActor = getOrCreateUserActor(userId)
// perUserActor is live now, but will it receive "msg"?
perUserActor.forward(msg)
}
def getOrCreateUserActor(userId: UserId): ActorRef = {
val childName = userId.toActorName
context.child(childName) match {
case Some(child) => child
case None => context.actorOf(Props(classOf[UserActor], userId), childName)
}
}
为了回收内存,在UserActors一段闲置之后过期(即计时器触发子actor调用context.stop(self)).
我的问题是我认为我在"getOrCreateUserActor"和接收转发消息的子actor之间存在竞争条件 - 如果子进程在该窗口中到期,则转发的消息将丢失.
有什么方法可以检测到这种边缘情况,还是重构UserActorRegistry以排除它？