多線程Java Socket編程示例

采用Java 5的ExecutorService來進行線程池的方式實現多線程,模擬客戶端多用戶向同一服務器端發送請求.
1.服務端

 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; // 線程池
     private   final   int  POOL_SIZE = 10 ; // 單個CPU線程池大小

 public  MultiThreadServer()  throws  IOException {
    serverSocket = new  ServerSocket(port);
     // Runtime的availableProcessor()方法返回當前系統的CPU數目.
    executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * POOL_SIZE);
    System.out.println( " 服務器啟動 " );
}

 public   void  service() {
     while ( true ) {
        Socket socket = null ;
         try   {
             // 接收客戶連接,只要客戶進行了連接,就會觸發accept();從而建立連接
            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();
            }
        }
    }
} </pre>2.客戶端
 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));
    }

}

 //  定義一個簡單的任務
 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);
                 //  發送關閉命令
                OutputStream socketOut  =  socket.getOutputStream();
                socketOut.write( " shutdown/r/n " .getBytes());

                 //  接收服務器的反饋
                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();
            }
        }

    } ;
}

}</pre>