多线程Java Socket编程示例

这篇做为学习孙卫琴<<Java网络编程精解>>的学习笔记吧.其中采用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. http://www.my400800.cn
        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