scala(8)Actor

Actor 用于并行计算 ，Actor之间可以进行消息发送。

case class 是理想的载体，Actor的优势在于不基于资源与锁的基础上，完成并发。

Actor的建立

import scala.actors._
class ActorOps {

}
object helloActor extends Actor{
def act(): Unit ={
for (i<-1 to 5){
println("the is a scala actor")
Thread.sleep(2000)
}
}
}
object ActorOps{
def main(args: Array[String]) {
helloActor.start()
}
}

不常用的Actor创建

import scala.actors.Actor._

val secondActor=actor{

for (i<-1 to 5){

println(“the is a second scala actor”)

Thread.sleep(2000)

}

Actor的消息机制

!单方面传输

!?必须等到另一个Actor完成

!!取得发过去消息的结果

import scala.actors._
class ActorOps {

}
object helloActor extends Actor{
def act(): Unit ={
while (true){
receive{
case x:Int => println("got an Int")
case _=>println("some other type")
}
}
}
}
object ActorOps{
def main(args: Array[String]) {
helloActor.start()
helloActor ! "hi,the is scala!"
helloActor ! 1
}

Actor共享线程

通过react来进行线程共享

import scala.actors._
object NameResolver extends Actor{
import java.net.{InetAddress,UnknownHostException}
def act() {
react {
case Net(name: String, actor: Actor) => actor ! getIP(name)//actor处可以改成sender表示发送的那个actor 用于回复发来的Actor
case "EXIT" => println("exiting")
case msg =>
println("Unhandled message:" + msg)
act()
}
}
def getIP(name:String): Option[InetAddress] ={
try{
Some(InetAddress.getByName(name))
}catch {
case _:UnknownHostException=>None
}
}
}object ActorOps {
def main(args: Array[String]) {
NameResolver.start
NameResolver ! ("www.baidu.com",self)//self代表当前actor，所以下面的self.receive能接收到信息
println(self.receiveWithin(1000){case x=>x})
}
}

多个Actor协同工作

下面程序NameResolve把处理好的数据发给helloActor 。

好的actor使用case class来完成传递消息，结束时使用匹配模式。

import scala.actors._
import scala.actors.Actor._
class ActorOps {

}

object NameResolver extends Actor{
import java.net.{InetAddress,UnknownHostException}
def act() {
react {
case (name: String, actor: Actor) => actor ! getIP(name)//接受一个元组并把消息传给actor
//      case Net(name: String, actor: Actor) => actor ! getIP(name)//使用case class传递数据
case "EXIT" => println("exiting")
case msg =>
println("Unhandled message:" + msg)
act()
}
}
def getIP(name:String): Option[InetAddress] ={
try{
Some(InetAddress.getByName(name))
}catch {
case _:UnknownHostException=>None
}
}
}
object helloActor extends Actor{
def act(): Unit ={
while (true){
receive{
case msg=> print("receive massage:"+msg)
case x:Int => println("got an Int")
case _=>println("some other type")
}
}
}
}
case class Net(name: String, actor: Actor)//case class
object ActorOps {
def main(args: Array[String]) {
NameResolver.start
NameResolver ! ("www.baidu.com",helloActor)//发送要解析的网址，发给的actor
//      NameResolver ! Net("www.baidu.com",helloActor)
helloActor.start()

}
}