UDP协议

谁践踏了优雅 2021-11-05 13:26 550阅读 0赞

### 1）UDP协议概述 ###

![20190807084647592.png][]

### 2）UDP服务器与客户端程序 ###

服务器端：
    
        String info ="......"
    
        //将信息封装成数据包
        byte[] bytes = info.getBytes();
    
       //客户端在5000端口监听
         DatagramPacket dp = new DatagramPacket(bytes,0,bytes.length,InetAddress.getByName("localhost"),5000);
    
      //服务器的端口
    DatagramSocket server = new DatagramSocket(3000);
    
         //发送数据包
          server.send(dp);
    
           server.close();
    
    客户端:
        //接收内容
        byte b[] new byte[1024];
    
        //接收内容
        DatagramPacket dp = new DatagramPacket(b,b.length);
    
        //客户端在5000端口等待
        DatagramSocket client = new DatagramSocket(5000);
    
        //接收内容 
         client.receive(dp);
    
        System.out.println(new String(dp.getData(),0,dp.getLength()));
    
        client.close();

![20190807100345597.png][]

package com.vince;
    import java.io.IOException;
    import java.net.*;
    
    public class UDPServiceDemp {
        public static void main(String[] args) {
            String info = "碧瑶很漂亮，我很喜欢!!!!!!";
           //将信息封装成数据包
            byte[] bytes = info.getBytes();
            try {
                /**
                 * 封装一个数据包
                 * offset：分组数据偏移量
                 * length：分组数据长度
                 * InetAddress：目的地址
                 * port：目的端口号
                 */
                DatagramPacket dp = new DatagramPacket(
                        bytes,
                        0,
                        bytes.length,
                        InetAddress.getByName("127.0.0.1"),
                        8000);
                //本程序的端口
                DatagramSocket socket = new DatagramSocket(9000);
                //发送数据包
                socket.send(dp);
                socket.close();
             }catch (UnknownHostException e){
                e.printStackTrace();
            } catch (SocketException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

![20190807100557674.png][]

package com.vince;
    import java.io.IOException;
    import java.net.DatagramPacket;
    import java.net.DatagramSocket;
    import java.net.SocketException;
    
    public class UDPClientDemo {
        public static void main(String[] args) {
           //接收内容
            byte[] bytes = new byte[1024];
            DatagramPacket dp = new DatagramPacket(bytes,bytes.length);
            try {
                //客户端在8000端口等待
                DatagramSocket socket = new DatagramSocket(8000);
                System.out.println("正在接收数据中......");
                //接收数据
                socket.receive(dp);
                String s = new String(dp.getData(),0,dp.getLength());
                System.out.println(s);
                socket.close();
            } catch (SocketException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

![20190807100733964.png][]

![20190807100810989.png][]

[20190807084647592.png]: /images/20211105/1eab369ad8a243f289c3962b5b54b3e8.png
[20190807100345597.png]: /images/20211105/7433ab6dda4548d5af932aaee7df85ba.png
[20190807100557674.png]: /images/20211105/d977ed1e88e048459d414916495dc897.png
[20190807100733964.png]: /images/20211105/b72c69608583467e90178027eaa62440.png
[20190807100810989.png]: /images/20211105/c0657365338349dbb9a0f2d71458590a.png