服务器程序EchoServer.java；

import java.io.*;

import java.net.*;

import java.util.concurrent.*;

public class EchoServer {

private int port=10000;

private ServerSocket serverSocket;

private ExecutorService executor;//线程池

private final int pool_size=4;

private int portForShutdown=10001;

private ServerSocket serverSocketForShutdown=null;

private boolean isShutdown=false;

private Thread shutdownThread=new Thread() //负责关闭服务器的线程

{

public void start()

{

this.setDaemon(true);    //设为守护线程

super.start();

}

public void run()

{

while(!isShutdown)

{

Socket socketForShutdown=null;

try{

socketForShutdown=serverSocketForShutdown.accept();

BufferedReader br=new BufferedReader(new InputStreamReader(socketForShutdown.getInputStream()));

String command=br.readLine();

if(command.equals("shutdown"))

{

long beginTime=System.currentTimeMillis();

socketForShutdown.getOutputStream().write("服务器正在关闭\r\n".getBytes());

isShutdown=true;

executor.shutdown();

while(!executor.isTerminated())

{

executor.awaitTermination(30, TimeUnit.SECONDS);

}

serverSocket.close();

long endTime=System.currentTimeMillis();

socketForShutdown.getOutputStream().write(("服务器已经关闭,耗时"+(beginTime-endTime)+"毫秒\r\n").getBytes());

socketForShutdown.close();

}else

{

socketForShutdown.getOutputStream().write("错误的命令\r\n".getBytes());

//socketForShutdown.close();

}

}catch(IOException e){

e.printStackTrace();

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

};

public EchoServer() throws IOException{

serverSocket=new ServerSocket(port);

serverSocket.setSoTimeout(60000);

serverSocketForShutdown=new ServerSocket(portForShutdown);

shutdownThread.start();

System.out.println("server started...");

}

public void service(){

while(!isShutdown){

Socket socket=null;

try {

socket=serverSocket.accept();

executor=Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors()*pool_size);

executor.execute(new Handler(socket));

} catch (IOException e) {

e.printStackTrace();

}

}

}

public static void main(String args[]){

try {

new EchoServer().service();

} catch (IOException e) {

e.printStackTrace();

}

}

}

***********************************************************************************

客户端程序EchoClient.java：

import java.io.*;

import java.net.*;

import java.util.*;

public class EchoClient {

private String host="localhost";

private int port=10000;

Socket socket=null;

public EchoClient() throws IOException{

socket=new Socket(host,port);

}

public static void main(String args[]){

try {

new EchoClient().talk();

} catch (IOException e) {

e.printStackTrace();

}

}

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 void talk(){

try{

BufferedReader br=this.getReader(socket);

PrintWriter pw=this.getWriter(socket);

BufferedReader localReader=new BufferedReader(new InputStreamReader(System.in));

String msg=null;

while((msg=localReader.readLine())!=null){

pw.println(msg);

System.out.println(br.readLine());

if(msg.equalsIgnoreCase("bye"))

break;

}

}catch(IOException e){

e.printStackTrace();

}finally{

if(socket!=null)

try {

socket.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

}

*****************************************************************************************************************

Handler.java

import java.net.*;

import java.io.*;

public class Handler implements Runnable {

private Socket socket=null;

public Handler(Socket socket)

{

this.socket=socket;

}

public void run() {

try{

System.out.println("New connection accepted "+socket.getInetAddress()+":"+socket.getPort());

BufferedReader br=getReader(socket);

PrintWriter pw=this.getWriter(socket);

String msg=null;

while((msg=br.readLine())!=null)

{

System.out.println("server received: "+msg);

pw.println(echo(msg));

if(msg.equalsIgnoreCase("bye"))

break;

}

}catch(IOException e){

e.printStackTrace();

}finally{

try{

if(socket!=null)socket.close();

System.out.println("connection close..");

}

catch(IOException e){

e.printStackTrace();

}

}

}

public String echo(String msg){

return "echo:--->"+msg;

}

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));

}

}

******************************************************************************************************************

import java.net.*;

import java.io.*;

public class AdminClient {

public static void main(String args[])

{

Socket socket=null;

int port=10001;

try {

socket =new Socket("localhost",port);

OutputStream out=socket.getOutputStream();

out.write("shutdown\r\n".getBytes());

BufferedReader br=new BufferedReader(new InputStreamReader(socket.getInputStream()));

String msg=br.readLine();

System.out.println(msg);

} catch (UnknownHostException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

}finally{

try {

if(socket!=null)

socket.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

}