ExecutorService来进行线程池的方式实现多线程

ExecutorService来进行线程池的方式实现多线程

　采用Java 5的ExecutorService来进行线程池的方式实现多线程,模拟客户端多用户向同一服务器端发送请求.

1.服务端

package sterning;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.*;
import java.util.concurrent.*;

public class MultiThreadServer {
private int port=8821;
private ServerSocket serverSocket;
private ExecutorService executorService;//线程池
private final int POOL_SIZE=10;//单个CPU线程池大小

public MultiThreadServer() throws IOException{
serverSocket=new ServerSocket(port);
//Runtime的availableProcessor()方法返回当前系统的CPU数目.
executorService=Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors()*POOL_SIZE);
System.out.println("服务器启动");
}

public void service(){
while(true){
Socket socket=null;
try {
//接收客户连接,只要客户进行了连接,就会触发accept();从而建立连接
socket=serverSocket.accept();
executorService.execute(new Handler(socket));

} catch (Exception e) {
e.printStackTrace();
}
}
}

public static void main(String[] args) throws IOException {
new MultiThreadServer().service();
}

}

class Handler implements Runnable{
private Socket socket;
public Handler(Socket socket){
this.socket=socket;
}
private PrintWriter getWriter(Socket socket) throws IOException{
OutputStream socketOut=socket.getOutputStream();
return new PrintWriter(socketOut,true);
}
private BufferedReader getReader(Socket socket) throws IOException{
InputStream socketIn=socket.getInputStream();
return new BufferedReader(new InputStreamReader(socketIn));
}
public String echo(String msg){
return "echo:"+msg;
}
public void run(){
try {
System.out.println("New connection accepted "+socket.getInetAddress()+":"+socket.getPort());
BufferedReader br=getReader(socket);
PrintWriter pw=getWriter(socket);
String msg=null;
while((msg=br.readLine())!=null){
System.out.println(msg);
pw.println(echo(msg));
if(msg.equals("bye"))
break;
}
} catch (IOException e) {
e.printStackTrace();
}finally{
try {
if(socket!=null)
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
2.客户端
package sterning;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class MultiThreadClient {

public static void main(String[] args) {
int numTasks = 10;

ExecutorService exec = Executors.newCachedThreadPool();

for (int i = 0; i ＜ numTasks; i++) {
exec.execute(createTask(i));
}

}

// 定义一个简单的任务
private static Runnable createTask(final int taskID) {
return new Runnable() {
private Socket socket = null;
private int port=8821;

public void run() {
System.out.println("Task " + taskID + ":start");
try {
socket = new Socket("localhost", port);
// 发送关闭命令
OutputStream socketOut = socket.getOutputStream();
socketOut.write("shutdown\r\n".getBytes());

// 接收服务器的反馈
BufferedReader br = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
String msg = null;
while ((msg = br.readLine()) != null)
System.out.println(msg);
} catch (IOException e) {
e.printStackTrace();
}
}

};
}
}

　　从而实现了多个客户端向服务器端发送请求,服务器端采用多线程的方式来处理的情况.