UDP消息发送简单实现

发送数据包

package com.netCode;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

//UDP不需要连接服务器
public class UdpClientTest01 {
    public static void main(String[] args) throws Exception {
        //1.建立一个socket
        DatagramSocket socket=new DatagramSocket();
        //2.创建一个数据包
        InetAddress inetAddress=InetAddress.getByName("localhost");
        int port=9099;
        String msg="你好啊，我的傻老公";
        DatagramPacket datagramPacket=new DatagramPacket(msg.getBytes(),0,msg.getBytes().length,inetAddress,port);
        //3.发送数据包
        socket.send(datagramPacket);
        //4.关闭数据流
        socket.close();

    }
}

接收数据包

package com.netCode;

import java.net.DatagramPacket;
import java.net.DatagramSocket;

//还是要等待客户端连接
public class UdpServerTest02 {
    public static void main(String[] args)throws  Exception {
        //开发端口
        DatagramSocket datagramSocket=new DatagramSocket(9099);
        //接收数据包
        byte[] buffer=new byte[1024];
        DatagramPacket datagramPacket=new DatagramPacket(buffer,0,buffer.length);
        //阻塞接收
        datagramSocket.receive(datagramPacket);
        //打印收到的信息
        System.out.println(datagramPacket.getAddress().getHostAddress());
        System.out.println(new String(datagramPacket.getData(),0,datagramPacket.getLength()));
        //关闭连接
        datagramSocket.close();


    }
}

输出

127.0.0.1
你好啊，我的傻老公