[网络协议]DatagramSocket回复报文

发送端：
package com.suncreate.testSocket;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.util.Arrays;

public class UdpSend{

    public static void main(String[] args){
        try {
            DatagramSocket datagramSocket = new DatagramSocket(6500);
            byte[] buf=new byte[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
            System.out.println("-");
            DatagramPacket datagramPacket = new DatagramPacket(buf, 10, InetAddress.getByName("172.16.37.162"), 6400);
            System.out.println("--");
            datagramSocket.send(datagramPacket);
            System.out.println("---");
            datagramSocket.receive(datagramPacket);
            System.out.println(Arrays.toString(buf));
        }
        catch(Exception e)
            {
                e.printStackTrace();
            }
        }

}

接收端接收后回复:

package com.suncreate.testSocket;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.util.Arrays;

public class UdpReply?{
? ? public static void main(String[] args){
? ? ? ? try {
? ? ? ? ? ? DatagramSocket datagramSocket = new DatagramSocket(6400);
? ? ? ? ? ? byte[] buf=new byte[10];
? ? ? ? ? ? DatagramPacket packet= new DatagramPacket(buf,10);
? ? ? ? ? ? datagramSocket.receive(packet);
? ? ? ? ? ? System.out.println(Arrays.toString(buf));
? ? ? ? ? ? packet.setData(new byte[]{9,8,7,6,5,4,3,2,1,0});

? ? ? ? ? ?//直接修改接收的packet的数据，不用设置ip和port
? ? ? ? ? ? datagramSocket.send(packet);
? ? ? ? }
? ? ? ? catch(Exception e){

? ? ? ? }

? ? }
}