大数据学习——akka学习

架构图

重要类介绍

ActorSystem

在Akka中，ActorSystem是一个重量级的结构，他需要分配多个线程，所以在实际应用中，ActorSystem通常是一个单例对象，我们可以使用这个ActorSystem创建很多Actor。

Actor

在Akka中，Actor负责通信，在Actor中有一些重要的生命周期方法。

1.preStart()方法：该方法在Actor对象构造方法执行后执行，整个Actor生命周期中仅执行一次。

2.receive()方法：该方法在Actor的preStart方法执行完成后执行，用于接收消息，会被反复执行。

代码

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.itcast.akka</groupId>
    <artifactId>MyRPC</artifactId>
    <version>1.0</version>

    <properties>
        <maven.compiler.source>1.7</maven.compiler.source>
        <maven.compiler.target>1.7</maven.compiler.target>
        <encoding>UTF-8</encoding>
        <scala.version>2.10.6</scala.version>
        <scala.compat.version>2.10</scala.compat.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>${scala.version}</version>
        </dependency>

        <dependency>
            <groupId>com.typesafe.akka</groupId>
            <artifactId>akka-actor_2.10</artifactId>
            <version>2.3.14</version>
        </dependency>

        <dependency>
            <groupId>com.typesafe.akka</groupId>
            <artifactId>akka-remote_2.10</artifactId>
            <version>2.3.14</version>
        </dependency>

    </dependencies>

    <build>
        <sourceDirectory>src/main/scala</sourceDirectory>
        <testSourceDirectory>src/test/scala</testSourceDirectory>
        <plugins>
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.2.2</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>testCompile</goal>
                        </goals>
                        <configuration>
                            <args>
                                <arg>-make:transitive</arg>
                                <arg>-dependencyfile</arg>
                                <arg>${project.build.directory}/.scala_dependencies</arg>
                            </args>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>2.4.3</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <filters>
                                <filter>
                                    <artifact>*:*</artifact>
                                    <excludes>
                                        <exclude>META-INF/*.SF</exclude>
                                        <exclude>META-INF/*.DSA</exclude>
                                        <exclude>META-INF/*.RSA</exclude>
                                    </excludes>
                                </filter>
                            </filters>
                            <transformers>
                                <transformer
                                        implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                                    <resource>reference.conf</resource>
                                </transformer>
                                <transformer
                                        implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>cn.itcast.akkk.Master</mainClass>
                                </transformer>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

package cn.itcast.akka

import akka.actor.{Actor, ActorSystem, Props}
import akka.actor.Actor.Receive
import com.typesafe.config.ConfigFactory

/**
  * Created by ZhaoXing on 2016/8/18.
  */
class Master extends Actor {
  override def receive: Receive = {
    case "start" => {
      println("starting...")
      println("started")
    }
    case "stop" => {
      println("stopping...")
      println("stopped")
    }

    //Master接收到Worker的消息
    case "connect" => {
      println("a client connected...")
      //向Worker反馈消息
      sender ! "success"
    }

    case _ => println("123")
  }
}

object Master {
  def main(args: Array[String]) {
    val host = "127.0.0.1"
    val port = 8888
    //    val host = args(0)
    //    val port = args(1).toInt

    val confStr =
      s"""
         |akka.actor.provider = "akka.remote.RemoteActorRefProvider"
         |akka.remote.netty.tcp.hostname = "$host"
         |akka.remote.netty.tcp.port = "$port"
       """.stripMargin

    val conf = ConfigFactory.parseString(confStr)
    //ActorSystem是单例的，用于创建Acotor并监控actor
    val actorSystem = ActorSystem("MaterActorSystem", conf)
    //通过ActorSystem创建Actor
    val master = actorSystem.actorOf(Props[Master], "Master")

    master ! "start"
    master ! "hello"
    master ! "stop"

    actorSystem.awaitTermination()

  }
}

package cn.itcast.akka

import akka.actor.{Actor, ActorSystem, Props}
import akka.actor.Actor.Receive
import com.typesafe.config.ConfigFactory

/**
  * Created by ZhaoXing on 2016/8/18.
  */
class Worker extends Actor {

  //preStart在构造器之后receive之前执行
  override def preStart(): Unit = {
    //首先跟Master建立连接
    val master = context.actorSelection("akka.tcp://MaterActorSystem@127.0.0.1:8888/user/Master")
    //通过mater的引用向Master发送消息
    master ! "connect"
  }

  override def receive: Receive = {
    case "success" => {
      println("a msg for master：success")
    }
  }
}

object Worker {
  def main(args: Array[String]) {

    val host = "127.0.0.1"
    val port = 8889
    //    val host = args(0)
    //    val port = args(1).toInt
    val confStr =
      s"""
         |akka.actor.provider = "akka.remote.RemoteActorRefProvider"
         |akka.remote.netty.tcp.hostname = "$host"
         |akka.remote.netty.tcp.port = "$port"
       """.stripMargin
    val conf = ConfigFactory.parseString(confStr)
    //单例的ActorSystem
    val actorSystem = ActorSystem("WorkerActorSystem", conf)
    //通过actorSystem来创建Actor
    val worker = actorSystem.actorOf(Props[Worker], "Worker")
    actorSystem.awaitTermination()
  }
}