本節主要內容

停止執行Typed Actor

當Typed Actor不再需要時要將其停止，有3種方法停止Typed Actor的執行：
（1）通過system.shutdown()停止ActorSystem中所有的Typed Actor；
（2）呼叫TypedActor(system).stop(mySquarer)停止指定的Typed Actor；
（3）呼叫TypedActor(system).poisonPill(otherSquarer)停止指定的Typed Actor。
具體使用程式碼如下：

/*
 * 停止Typed Actor
 */
object
 
 Example_3 extends  App {

  import akka.event.Logging
  import scala.concurrent.{ Promise, Future }
  import akka.actor.{ TypedActor, TypedProps }
  import scala.concurrent.duration._

  trait Squarer {
    //fire-and-forget訊息
    def squareDontCare(i: Int): Unit
    //非阻塞send-request-reply訊息
    def square(i: Int): Future[Int]
    //阻塞式的send-request-reply訊息
 

    def squareNowPlease(i: Int): Option[Int]
    //阻塞式的send-request-reply訊息
    def squareNow(i: Int): Int
  }


  //混入PostStop和PreStart
  class SquarerImpl(val name: String) extends  Squarer with PostStop with PreStart {
    import TypedActor.context
    val log = Logging(context.system,TypedActor.self.getClass())
    def
 
 this() = this("SquarerImpl")

    def squareDontCare(i: Int): Unit = i * i
    def square(i: Int): Future[Int] = Promise.successful(i * i).future
    def squareNowPlease(i: Int): Option[Int] = Some(i * i)
    def squareNow(i: Int): Int = i * i

    def postStop(): Unit={
      log.info ("TypedActor Stopped")
    }
    def preStart(): Unit={
      log.info ("TypedActor  Started")
    }
  }


  val system = ActorSystem("TypedActorSystem")
  val log = Logging(system, this.getClass)

  //使用預設建構函式建立Typed Actor
  val mySquarer: Squarer =
    TypedActor(system).typedActorOf(TypedProps[SquarerImpl](),"mySquarer")


  //使用非預設建構函式建立Typed Actor
  val otherSquarer: Squarer =
    TypedActor(system).typedActorOf(TypedProps(classOf[Squarer],
      new SquarerImpl("SquarerImpl")), "otherSquarer")

  //Request-reply-with-future 訊息傳送
  val fSquare = mySquarer.square(10)
  val result = Await.result(fSquare, 5 second)
  log.info("fSquare="+result)

  //呼叫poisonPill方法停止Actor執行
  TypedActor(system).poisonPill(otherSquarer)

  //呼叫stop方法停止Actor執行
  TypedActor(system).stop(mySquarer)

  //system.shutdown()
}

程式碼執行結果如下所示。

[INFO][03/21/2016 22:41:51.119][TypedActorSystem-akka.actor.default-dispatcher-2][$Proxy0(akka://TypedActorSystem)] TypedActor  Started
[INFO][03/21/2016 22:41:51.123][TypedActorSystem-akka.actor.default-dispatcher-2][$Proxy1(akka://TypedActorSystem)] TypedActor  Started
[INFO][03/21/2016 22:41:51.124][main][Example12_10$(akka://TypedActorSystem)] fSquare=100
[INFO][03/21/2016 22:41:51.131][TypedActorSystem-akka.actor.default-dispatcher-5][$Proxy1(akka://TypedActorSystem)] TypedActor Stopped
[INFO][03/21/2016 22:41:51.131][TypedActorSystem-akka.actor.default-dispatcher-3][$Proxy0(akka://TypedActorSystem)] TypedActor Stopped

程式碼中類SquarerImpl 混入了PreStart和PostStop兩個trait：class SquarerImpl(val name: String) extends Squarer with PostStop with PreStart，這樣的話在建立TypedActor之前和停止TypedActor後能夠進行相應的操作，本例中主要是為監視TypedActor的建立和停止過程。程式碼TypedActor(system).stop(mySquarer)通過stop方法停止TypedActor，而TypedActor(system)
.poisonPill(otherSquarer)通過呼叫poisonPill方法停止執行TypedActor。