java--网络编程

1.Client端

import java.net.* ;
import java.io.* ;

public class Client {
    public static void main(String[] args) throws Exception {
        
        Socket s = new Socket("localhost",8888);
        
        //向服务器发送消息
        InputStreamReader r = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(r);
        System.out.println("Input your want to write : " );
        String msg = br.readLine();
        
        OutputStream os = s.getOutputStream();
        
        DataOutputStream ds = new DataOutputStream(os);
        ds.writeUTF(msg);
        
        //接受来自服务器的消息
        InputStream r1 = s.getInputStream();
        DataInputStream dis = new DataInputStream(r1);
        String serverMsg = dis.readUTF();
        System.out.println("Reverse the Server massage is : " + serverMsg );
        
        br.close();
        s.close();
    }
}

2.Server端

import java.net.*;
import java.io.* ;

public class Server {
    public static void main(String[] args) throws Exception {
        ServerSocket serverSocket = new ServerSocket(8888);
        while(true) {
            
            //接受客户端消息
            Socket socket = serverSocket.accept();
            System.out.println("a client connect this server !");
            InputStream r = socket.getInputStream();
        
            DataInputStream dis = new DataInputStream(r);
            String clientMsg = dis.readUTF();
            System.out.println("send to this server : " + clientMsg);
            
            //向客户端回复消息
            BufferedReader input = new BufferedReader(
                new InputStreamReader(System.in)
            );
            String backMsg = input.readLine();
            OutputStream os = socket.getOutputStream();
            DataOutputStream dos = new DataOutputStream(os);
            dos.writeUTF(backMsg);
            input.close();
        }
    }
}

以上代码实现了点对点的通信。

在网上看到了一篇文章讲的是网络编程UDP 实现点对点通信。http://computerdragon.blog.51cto.com/6235984/1194280这是网址，可以参考，讲的很详细。