JavaSE-21.2.2【案例-UDP通信程序（“多人聊天室”）】

package day12.lesson2.p1;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;

/*
2.3 案例-UDP通信程序

    UDP发送数据：数据来自于键盘录入，直到输入的数据是886，发送数据结束
    UDP接收数据：因为接收端不知道发送端什么时候停止发送，故采用死循环接收

 */
public class SendDemo {
    public static void main(String[] args) throws IOException {
        DatagramSocket ds = new DatagramSocket();

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String line;
        while ((line=br.readLine()) != null){
            if("886".equals(line)){
                break;
            }

            byte[] bytes = line.getBytes();
            DatagramPacket dp = new DatagramPacket(
                    bytes,
                    bytes.length,
                    InetAddress.getByName("MSI-YUBABY"),
                    12345
            );

            ds.send(dp);
        }

        ds.close();
    }
}

package day12.lesson2.p1;

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

public class ReceiveDemo {
    public static void main(String[] args) throws IOException {
        DatagramSocket ds = new DatagramSocket(12345);

        while (true){
            byte[] bytes = new byte[1024];
            DatagramPacket dp = new DatagramPacket(bytes, bytes.length);

            ds.receive(dp);

            System.out.println("接收到的数据：" + new String(
                    dp.getData(),
                    0,
                    dp.getLength()
            ));
        }

//        ds.close();
        //启动一个ReceiveDemo-main，启动多个SendDemo-main，即可组成“聊天室”
    }
}