使用UDP實現簡單聊天功能

使用UDP實現一個簡單的多人聊天功能。該程式使用了多執行緒，實現了聊天功能。

package 課後作業.E103_10_聊天;

import java.io.IOException;
import java.net.*;
import java.util.Scanner;

//接收
class Receive implements Runnable{
    @Override
    public void run() {
        DatagramSocket receiveSocket = null;
        try {
            receiveSocket = new
 
 DatagramSocket(5200);
        } catch (SocketException e) {
            e.printStackTrace();
        }

        while (true) {
            byte[] bytes = new byte[1024];
            //建立一個報文，於與接收
            DatagramPacket datagramPacket = new DatagramPacket(bytes, bytes.length);
            //接收
            try
 
 {
                receiveSocket.receive(datagramPacket);
            } catch (IOException e) {
                e.printStackTrace();
            }
            InetAddress ip = datagramPacket.getAddress();

            System.out.println(ip.getHostName()+ new String(datagramPacket.getData()));
        }
    }
}

//傳送
 

class Send implements Runnable{
    @Override
    public void run() {
        DatagramSocket sendSocket = null;
        try {
            sendSocket = new DatagramSocket();
        } catch (SocketException e) {
            e.printStackTrace();
        }
        Scanner scan = new Scanner(System.in);
        while (true) {
            String str = scan.next();
            //要傳送的資訊
            byte[] bytes = str.getBytes();
            //傳送的目標地址
            InetAddress inetAddress = null;
            try {
                inetAddress = InetAddress.getByName("192.168.108.32");
            } catch (UnknownHostException e) {
                e.printStackTrace();
            }
            //資料報文
            DatagramPacket datagramPacket = new DatagramPacket(bytes, bytes.length, inetAddress, 5200);
            //傳送
            try {
                sendSocket.send(datagramPacket);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

public class Test {
    public static void main(String[] args) {
        Receive receive = new Receive();
        Thread thread = new Thread(receive);
        thread.start();

        Send send = new Send();
        Thread thread1 = new Thread(send);
        thread1.start();
    }
}

執行結果：

這裡實現的是兩人聊天，想要實現多人聊天只需要將接受地址改成廣播地址即可。