Java编写一个简单的TCP通信程序。服务器发送一条字符串，客户端接收该信息并显示。

import  java.io.DataOutputStream;
import  java.io.IOException;
import  java.net.ServerSocket;
import  java.net.Socket;

public  class  SocketServer {

    private  static  final  int  PORT =  8088 ;

    public  static  void  main(String[] args) {
        ServerSocket server =  null ;
        try  {
            server =  new  ServerSocket(PORT);
            while  ( true ) {
                Socket client = server.accept();
                new  Thread( new  Server(client)).start();
            }
        }  catch  (IOException e) {
            e.printStackTrace();
        }
    }

}

class  Server  implements  Runnable {

    private  Socket client;

    public  Server(Socket client) {
        this .client = client;
    }

    public  void  run() {
        DataOutputStream output =  null ;
        try  {
            output =  new  DataOutputStream(client.getOutputStream());
            output.writeUTF( "XXOOXXOOXXOO" );
        }  catch  (IOException e) {
            e.printStackTrace();
        }  finally  {
            try  {
                if  (output !=  null ) output.close();
                output =  null ;
            }  catch  (IOException e) {}
        }
    }

}

2、客户端

import  java.io.DataInputStream;
import  java.io.IOException;
import  java.net.Socket;
import  java.net.UnknownHostException;

public  class  Client  extends  Socket {

    private  static  final  int  PORT =  8088 ;

    public  static  void  main(String[] args) {
        Socket socket =  null ;
        try  {
            socket =  new  Socket( "127.0.0.1" , PORT);
            DataInputStream in =  new  DataInputStream(socket.getInputStream());
            String res = in.readUTF();
            System.out.println(res);
            if  (in !=  null ) in.close();
        }  catch  (UnknownHostException e) {
            e.printStackTrace();
        }  catch  (IOException e) {
            e.printStackTrace();
        }  finally  {
            if  (socket !=  null ) {
                try  {
                    socket.close();
                }  catch  (IOException e) {}
            }
        }
    }
}