本节主要内容：
1. 停止Actor
1. 停止Actor
（1）通过ActorSystem.shutdown方法停止所有 Actor的运行
/*
*停止Actor:ActorSystem.shutdown方法
*/
object Example_10 extends App{
import akka.actor.Actor
import akka.actor.ActorSystem
import akka.actor.Props
class FirstActor extends Actor with ActorLogging{
var child:ActorRef = context.actorOf(Props[MyActor], name = "myActor")
def receive = {
//向MyActor发送消息
case x => child ! x;log.info("received "+x)
}
override def postStop(): Unit = {
log.info("postStop In FirstActor")
}
}
class MyActor extends Actor with ActorLogging{
def receive = {
case "test" => log.info("received test");
case _ => log.info("received unknown message");
}
override def postStop(): Unit = {
log.info("postStop In MyActor")
}
}
val system = ActorSystem("MyActorSystem")
val systemLog=system.log
//创建FirstActor对象
val firstactor = system.actorOf(Props[FirstActor], name = "firstActor")
systemLog.info("准备向firstactor发送消息")
//向firstactor发送消息
firstactor!"test"
firstactor! 123
//关闭ActorSystem，停止所有Acotr运行
system.shutdown()
}代码运行结果：
[INFO] [04/02/2016 21:51:34.440] [main] [ActorSystem(MyActorSystem)] 准备向firstactor发送消息
[INFO] [04/02/2016 21:51:34.441] [MyActorSystem-akka.actor.default-dispatcher-4] [akka://MyActorSystem/user/firstActor/myActor] received test
[INFO] [04/02/2016 21:51:34.441] [MyActorSystem-akka.actor.default-dispatcher-2] [akka://MyActorSystem/user/firstActor] received test
[INFO] [04/02/2016 21:51:34.441] [MyActorSystem-akka.actor.default-dispatcher-2] [akka://MyActorSystem/user/firstActor] received 123
[INFO] [04/02/2016 21:51:34.441] [MyActorSystem-akka.actor.default-dispatcher-4] [akka://MyActorSystem/user/firstActor/myActor] received unknown message
[INFO] [04/02/2016 21:51:34.446] [MyActorSystem-akka.actor.default-dispatcher-4] [akka://MyActorSystem/user/firstActor/myActor] postStop In MyActor
[INFO] [04/02/2016 21:51:34.447] [MyActorSystem-akka.actor.default-dispatcher-5] [akka://MyActorSystem/user/firstActor] postStop In FirstActor
（2）通过context.stop方法停止Actor的运行
/*
*停止Actor:context.stop方法
*/
object Example_11 extends App{
import akka.actor.Actor
import akka.actor.ActorSystem
import akka.actor.Props
class FirstActor extends Actor with ActorLogging{
var child:ActorRef = context.actorOf(Props[MyActor], name = "myActor")
def receive = {
case "stop"=>context.stop(child)
case x =>{
//向MyActor发送消息
child ! x
log.info("received "+x)
}
}
override def postStop(): Unit = {
log.info("postStop In FirstActor")
}
}
class MyActor extends Actor with ActorLogging{
def receive = {
case "test" => log.info("received test");
case _ => log.info("received unknown message");
}
override def postStop(): Unit = {
log.info("postStop In MyActor")
}
}
val system = ActorSystem("MyActorSystem")
val systemLog=system.log
//创建FirstActor对象
val firstactor = system.actorOf(Props[FirstActor], name = "firstActor")
systemLog.info("准备向firstactor发送消息")
//向firstactor发送消息
firstactor!"test"
firstactor! 123
firstactor!"stop"
}代码运行结果：
[INFO] [04/02/2016 22:02:48.760] [main] [ActorSystem(MyActorSystem)] 准备向firstactor发送消息
[INFO] [04/02/2016 22:02:48.761] [MyActorSystem-akka.actor.default-dispatcher-5] [akka://MyActorSystem/user/firstActor/myActor] received test
[INFO] [04/02/2016 22:02:48.761] [MyActorSystem-akka.actor.default-dispatcher-2] [akka://MyActorSystem/user/firstActor] received test
[INFO] [04/02/2016 22:02:48.762] [MyActorSystem-akka.actor.default-dispatcher-2] [akka://MyActorSystem/user/firstActor] received 123
[INFO] [04/02/2016 22:02:48.762] [MyActorSystem-akka.actor.default-dispatcher-5] [akka://MyActorSystem/user/firstActor/myActor] received unknown message
[INFO] [04/02/2016 22:02:48.763] [MyActorSystem-akka.actor.default-dispatcher-5] [akka://MyActorSystem/user/firstActor/myActor] postStop In MyActor
代码的重点为
class FirstActor extends Actor with ActorLogging{
var child:ActorRef = context.actorOf(Props[MyActor], name = "myActor")
def receive = {
case "stop"=>context.stop(child)
case x =>{
//向MyActor发送消息
child ! x
log.info("received "+x)
}
}
override def postStop(): Unit = {
log.info("postStop In FirstActor")
}
}中的case “stop”=>context.stop(child)，直接通过context.stop方法停止Actor的运行。注意程序中并没有使用system.shutdown方法，因此整个程序的不会停止，如下图所示 
（3）通过akka.actor.PoisonPill消息停止Actor的运行
/*
*停止Actor:使用akka.actor.PoisonPill
*/
object Example_12 extends App{
import akka.actor.Actor
import akka.actor.ActorSystem
import akka.actor.Props
import akka.actor.PoisonPill
class FirstActor extends Actor with ActorLogging{
var child:ActorRef = context.actorOf(Props[MyActor], name = "myActor")
def receive = {
//向child发送PoisonPill停止其运行
case "stop"=>child!PoisonPill
case x =>{
//向MyActor发送消息
child ! x
log.info("received "+x)
}
}
override def postStop(): Unit = {
log.info("postStop In FirstActor")
}
}
class MyActor extends Actor with ActorLogging{
def receive = {
case "test" => log.info("received test");
case _ => log.info("received unknown message");
}
override def postStop(): Unit = {
log.info("postStop In MyActor")
}
}
val system = ActorSystem("MyActorSystem")
val systemLog=system.log
//创建FirstActor对象
val firstactor = system.actorOf(Props[FirstActor], name = "firstActor")
systemLog.info("准备向firstactor发送消息")
//向firstactor发送消息
firstactor!"test"
firstactor! 123
firstactor!"stop"
}代码运行结果：
[INFO] [04/02/2016 22:12:09.947] [main] [ActorSystem(MyActorSystem)] 准备向firstactor发送消息
[INFO] [04/02/2016 22:12:09.947] [MyActorSystem-akka.actor.default-dispatcher-2] [akka://MyActorSystem/user/firstActor/myActor] received test
[INFO] [04/02/2016 22:12:09.947] [MyActorSystem-akka.actor.default-dispatcher-4] [akka://MyActorSystem/user/firstActor] received test
[INFO] [04/02/2016 22:12:09.947] [MyActorSystem-akka.actor.default-dispatcher-4] [akka://MyActorSystem/user/firstActor] received 123
[INFO] [04/02/2016 22:12:09.947] [MyActorSystem-akka.actor.default-dispatcher-2] [akka://MyActorSystem/user/firstActor/myActor] received unknown message
[INFO] [04/02/2016 22:12:09.951] [MyActorSystem-akka.actor.default-dispatcher-4] [akka://MyActorSystem/user/firstActor/myActor] postStop In MyActor代码与Exampel_11中的不同之处在于
//向child发送PoisonPill停止其运行
case "stop"=>child!PoisonPill它使用不是context.stop方法，而是向MyActor发送了PoisonPill消息，其它代码不变。
还有一种gracefulStop方法可以停止Actor的运行，这部分内容等了解完Future类的作用原理之后再来讨论
Scala学习（公众微信号：ScalaLearning）每天为大家带来一点Scala语言、Spark、Kafka、Flink、AKKA等大数据技术干货及相关技术资讯。技术永无止境，勇攀高峰，一往直前！
觉得文章不错？扫描关注
