akka简单示例-1

刚刚开始接触akka，网上找了2个简单示例，并在公司运营机器上尝试，踩了一些坑，在此记录。

1. 本地hello world

 [torstan@sparkb5-i ~/akka_example/hello_world]$ cat src/helloWorld.scala
 package our.examples
 import akka.actor.Actor
 import akka.actor.ActorSystem
 import akka.actor.Props

 class HelloActor extends Actor {
   def receive = {
     case "hello" => println("hello back at you")
     case _       => println("huh?")
   }
 }

 object HelloApp extends App {
         override def main(args: Array[String]){
                 val system = ActorSystem("HelloSystem")
                         // default Actor constructor
                         val helloActor = system.actorOf(Props[HelloActor], name = "helloactor")
                         helloActor ! "hello"
                         helloActor ! "buenos dias"
         }
 }

 [torstan@sparkb5-i ~/akka_example/hello_world]$ cat Makefile
 SRC_DIR := src
 SRC := $(shell find ${SRC_DIR} -name "*.scala")
 DIR=our

 TARGET := HelloApp.jar

 SCALAC := scalac
 SCFLAGS := /usr/local/scala-2.10.4/lib/akka-actors.jar  

 .PHONY: all clean

 all: ${TARGET}

 ${TARGET}: ${SRC}
         ${SCALAC} -cp ${SCFLAGS} $^

 clean:
         ${RM} -r ${TARGET} ${DIR}

 [torstan@sparkb5-i ~/akka_example/hello_world]$ cat run.sh
 #!/bin/bash

 java -cp \
  .:/usr/local/scala-2.10.4/lib/scala-library.jar:/usr/local/scala-2.10.4/lib/akka-actors.jar:/usr/local/scala-2.10.4/lib/typesafe-config.jar\
   our.examples.HelloApp

执行结果：

[torstan@sparkb5-i ~/akka_example/hello_world]$ ./run.sh
hello back at you
huh?

2. 简单CS示例

server端：

 [torstan@sparkb5-i ~/akka_example/remote_service/server]$ cat src/HelloRemote.scala
 package remote
 import akka.actor.Actor
 import akka.actor.ActorSystem
 import akka.actor.Props

 class RemoteActor extends Actor{
         def receive = {
                 case msg:String =>
                         println(s"RemoteActor received message '$msg'")
                         sender ! "hello from RemoteActor"
         }
 }

 object HelloRemote extends App{
         val system = ActorSystem("HelloRemoteSystem")
         val remoteActor = system.actorOf(Props[RemoteActor], name="RemoteActor")
         remoteActor ! "The remote actor is alive"
 }

 [torstan@sparkb5-i ~/akka_example/remote_service/server]$ cat application.conf
 akka {
   loglevel = "DEBUG"
   actor {
     provider = "akka.remote.RemoteActorRefProvider"
    }
    remote {
      transport = "akka.remote.netty.NettyRemoteTransport"
      //log-sent-messages = on
      //log-received-messages = on
      netty {
        hostname = "172.27.6.240"
        port = 5150
      }
    }
 }

 [torstan@sparkb5-i ~/akka_example/remote_service/server]$ cat Makefile
 SRC_DIR := src
 SRC := $(shell find ${SRC_DIR} -name "*.scala")
 DIR=remote

 TARGET := HelloRemote.jar

 SCALAC := scalac
 SCFLAGS := /usr/local/scala-2.10.4/lib/akka-actors.jar  

 .PHONY: all clean

 all: ${TARGET}

 ${TARGET}: ${SRC}
         ${SCALAC} -cp ${SCFLAGS} $^

 clean:
         ${RM} -r ${TARGET} ${DIR}

 [torstan@sparkb5-i ~/akka_example/remote_service/server]$ cat run.sh
 #!/bin/bash

 AKKA_LIB_PATH="/usr/local/akka-2.1.4/lib/akka/"

 java -cp \
  .:/usr/local/scala-2.10.4/lib/scala-library.jar:/usr/local/scala-2.10.4/lib/akka-actors.jar:/usr/local/scala-2.10.4/lib/typesafe-config.jar:${AKKA_LIB_PATH}/akka-remote_2.10-2.1.4.jar:${AKKA_LIB_PATH}/protobuf-java-2.4.1.jar:${AKKA_LIB_PATH}/netty-3.5.8.Final.jar \
  remote.HelloRemote

client端：

 [torstan@sparkb5-i ~/akka_example/remote_service/client]$ cat src/HelloLocal.scala
 package client
 import akka.actor._

 object HelloLocal extends App{
         implicit val system = ActorSystem("LocalSystem")
         val localActor = system.actorOf(Props[LocalActor], name="LocalActor")
         localActor ! "START"
 }

 class LocalActor extends Actor{
         val remote = context.actorFor("akka://HelloRemoteSystem@172.27.6.240:5150/user/RemoteActor")
         var counter = 0
         def receive = {
                 case "START" =>
                         remote ! "HELLO from the LocalActor"
                 case msg:String =>
                         println(s"LocalActor received message: '$msg'")
                         if(counter < 5){
                                 sender ! "hello back to you"
                                 counter += 1
                         }
         }
 }

 [torstan@sparkb5-i ~/akka_example/remote_service/client]$ cat application.conf
 akka {
   //loglevel = "DEBUG"
   actor {
     provider = "akka.remote.RemoteActorRefProvider"
   }
   remote {
     transport = "akka.remote.netty.NettyRemoteTransport"
     //log-sent-messages = on
     //log-received-messages = on
     netty {
       hostname = "127.0.0.1"
       port = 0
     }
   }
 }

 [torstan@sparkb5-i ~/akka_example/remote_service/client]$ cat Makefile
 SRC_DIR := src
 SRC := $(shell find ${SRC_DIR} -name "*.scala")
 DIR=client

 TARGET := HelloLocal.jar

 SCALAC := scalac
 SCFLAGS := /usr/local/scala-2.10.4/lib/akka-actors.jar  

 .PHONY: all clean

 all: ${TARGET}

 ${TARGET}: ${SRC}
         ${SCALAC} -cp ${SCFLAGS} $^

 clean:
         ${RM} -r ${TARGET} ${DIR}

 [torstan@sparkb5-i ~/akka_example/remote_service/client]$ cat run.sh
 #!/bin/bash

 AKKA_LIB_PATH="/usr/local/akka-2.1.4/lib/akka/"

 java -cp \
  .:/usr/local/scala-2.10.4/lib/scala-library.jar:/usr/local/scala-2.10.4/lib/akka-actors.jar:/usr/local/scala-2.10.4/lib/typesafe-config.jar:${AKKA_LIB_PATH}/akka-remote_2.10-2.1.4.jar:${AKKA_LIB_PATH}/protobuf-java-2.4.1.jar:${AKKA_LIB_PATH}/netty-3.5.8.Final.jar \
  client.HelloLocal

执行结果：

[root@sparkb5-0 /data/torstan/akka_example/remote_service/server]# ./run.sh
[DEBUG] [12/10/2014 17:31:57.074] [main] [EventStream(akka://HelloRemoteSystem)] logger log1-Logging$DefaultLogger started
[DEBUG] [12/10/2014 17:31:57.080] [main] [EventStream(akka://HelloRemoteSystem)] Default Loggers started
[INFO] [12/10/2014 17:31:57.269] [main] [NettyRemoteTransport(akka://HelloRemoteSystem@172.27.6.240:5150)] RemoteServerStarted@akka://HelloRemoteSystem@172.27.6.240:5150
RemoteActor received message 'The remote actor is alive'
[INFO] [12/10/2014 17:32:01.768] [HelloRemoteSystem-10] [NettyRemoteTransport(akka://HelloRemoteSystem@172.27.6.240:5150)] RemoteClientStarted@akka://LocalSystem@127.0.0.1:48437
[DEBUG] [12/10/2014 17:32:01.769] [HelloRemoteSystem-10] [RemoteClient(akka://HelloRemoteSystem)] Starting remote client connection to [akka://LocalSystem@127.0.0.1:48437]
[DEBUG] [12/10/2014 17:32:01.771] [HelloRemoteSystem-10] [NettyRemoteTransport(akka://HelloRemoteSystem@172.27.6.240:5150)] RemoteServerClientConnected@akka://HelloRemoteSystem@172.27.6.240:5150: Client[akka://LocalSystem@127.0.0.1:48437]
RemoteActor received message 'HELLO from the LocalActor'
[DEBUG] [12/10/2014 17:32:01.782] [HelloRemoteSystem-akka.actor.default-dispatcher-2] [akka.serialization.Serialization(akka://HelloRemoteSystem)] Using serializer[akka.serialization.JavaSerializer] for message [java.lang.String]
RemoteActor received message 'hello back to you'
RemoteActor received message 'hello back to you'
RemoteActor received message 'hello back to you'
RemoteActor received message 'hello back to you'
RemoteActor received message 'hello back to you'

[torstan@sparkb5-i ~/akka_example/remote_service/client]$ ./run.sh
[INFO] [12/10/2014 17:32:01.668] [main] [NettyRemoteTransport(akka://LocalSystem@127.0.0.1:48437)] RemoteServerStarted@akka://LocalSystem@127.0.0.1:48437
[INFO] [12/10/2014 17:32:01.755] [LocalSystem-akka.actor.default-dispatcher-3] [NettyRemoteTransport(akka://LocalSystem@127.0.0.1:48437)] RemoteClientStarted@akka://HelloRemoteSystem@172.27.6.240:5150
LocalActor received message: 'hello from RemoteActor'
LocalActor received message: 'hello from RemoteActor'
LocalActor received message: 'hello from RemoteActor'
LocalActor received message: 'hello from RemoteActor'
LocalActor received message: 'hello from RemoteActor'
LocalActor received message: 'hello from RemoteActor'

遇到的坑：

1. 运行时各种各样的依赖缺失

比如：

[torstan@sparkb5-i ~/akka_example/remote_service/client]$ ./run.sh 
Exception in thread "main" java.lang.ClassNotFoundException: akka.remote.RemoteActorRefProvider
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:270)
at akka.actor.ReflectiveDynamicAccess$$anonfun$getClassFor$1.apply(DynamicAccess.scala:68)
at akka.actor.ReflectiveDynamicAccess$$anonfun$getClassFor$1.apply(DynamicAccess.scala:67)
at scala.util.Try$.apply(Try.scala:161)

google到答案是没有加载依赖文件akka-remote.jar，后来发现是没有安装akka。

2. Exception in thread "main" java.lang.NoSuchMethodException: akka.remote.RemoteActorRefProvider.<init>(java.lang.String, akka.actor.ActorSystem$Settings, akka.event.EventStream, akka.actor.Scheduler, akka.actor.DynamicAccess

google到答案：

 

12 maj 2014 kl. 22:55 skrev Liang Tang <liang...@gmail.com>:

- show quoted text -

Yes, Scala 2.10 comes with Akka 2.1.0, which is not binary compatible with Akka 2.3.2. I recommend using sbt to resolve the dependencies instead of manually constructing a command line, i.e. using the runMain task.

 

Regards,

 

Roland

https://groups.google.com/forum/#!topic/akka-user/zibfABh4cs8

 

因为安装的scala版本scala-2.10.4与akka的版本akka-2.2.4不兼容，scala-2.10.4应该与akka-2.1.4配套使用。

 

 

参考文献：

http://alvinalexander.com/scala/simple-scala-akka-actor-examples-hello-world-actors

http://alvinalexander.com/scala/simple-akka-actors-remote-example