代码

UDPTest类

package com.day0321_1;

import org.junit.jupiter.api.Test;

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

/**
 * UDP协议的网络编程
 */
public class UDPTest {

    //发送端
    @Test
    public void sender()throws IOException {

        DatagramSocket socket = new DatagramSocket();

        String str="我是UDP方式发送的导弹";
        byte[] data = str.getBytes();
        InetAddress inet=InetAddress.getLocalHost();
        DatagramPacket packet = new DatagramPacket(data,0,data.length,inet,9090);

        socket.send(packet);

        socket.close();


    }

    //接收端
    @Test
    public void receiver()throws IOException{

        DatagramSocket socket=new DatagramSocket(9090);

        byte[] buffer=new byte[100];
        DatagramPacket packet = new DatagramPacket(buffer,0,buffer.length);

        socket.receive(packet);

        System.out.println(new String(packet.getData(),0,packet.getLength()));

        socket.close();

    }

}

二、图片