发送方

package top.ltyzqhh.Net;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketException;

public class UdpSenderDemo01 {
    public static void main(String[] args) throws Exception {
        DatagramSocket socket = new DatagramSocket(8888);

        //控制台读取 System.in
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        while (true){

            String data = reader.readLine();

            byte[] bytes = data.getBytes();
            DatagramPacket packet = new DatagramPacket(bytes,0,bytes.length,new InetSocketAddress("localhost",6666));

            socket.send(packet);
            if (data.equals("bye"))
            {
                break;
            }
        }

        socket.close();
    }
}

接受方

package top.ltyzqhh.Net;

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

public class UdpReceiveDemo01 {
    public static void main(String[] args) throws Exception {
        DatagramSocket socket = new DatagramSocket(6666);

        while(true)
        {
            //准备接收包裹
            byte[] container = new byte[1024];
            DatagramPacket packet = new DatagramPacket(container,0,container.length);
            socket.receive(packet);//阻塞式接受包裹
            //断开连接
            byte[] data =packet.getData();
            String Receivedata = new String(data, 0, data.length);

            System.out.println(Receivedata);

            if (Receivedata.equals("bye"))
            {
                break;
            }

        }

        socket.close();
    }
}