[网络协议]Java 实现简单的聊天功能

?本案例利用UPD与多线程实现简单的UDP报文发送

public class Send implements Runnable {
    DatagramSocket datagramSocket = null;
    BufferedReader reader;
    private int port;
    private String hostname;
    private int ServerPort;

    public Send(int port, String hostname, int serverPort) {
        this.port = port;
        this.hostname = hostname;
        this.ServerPort = serverPort;
        try {
            datagramSocket = new DatagramSocket(port);
            reader = new BufferedReader(new InputStreamReader(System.in));
        } catch (SocketException e) {
            e.printStackTrace();
        }

    }

    @Override
    public void run() {
        System.out.println("发送端");
        while (true) {
            try {
                String str = reader.readLine();
                byte[] bytes = str.getBytes("UTF-8");
                DatagramPacket packet = new DatagramPacket(bytes, 0, bytes.length, new InetSocketAddress(this.hostname, this.ServerPort));
                datagramSocket.send(packet);


            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }
}

?

package com.example.test1115.UDPTest;

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

public class Receive implements Runnable {
   DatagramSocket datagramSocket = null;
    private int port;
    private String ClientName;

    public Receive(int port, String hostname) {
        this.port = port;
        this.ClientName = hostname;
        try {
            datagramSocket = new DatagramSocket(port);
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run(){
        System.out.println("接受端");
        while (true) {
            try {
                byte[] bytes = new byte[1024];
                DatagramPacket packet = new DatagramPacket(bytes, 0, bytes.length);
                datagramSocket.receive(packet);

                byte[] data = packet.getData();
                String receive = new String(data, 0, data.length,"UTF-8");
                System.out.println(this.ClientName + ":" + receive);

            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

?创建学生端和老师端，构造器里的数字是端口号，将其给成对方的即可

public class Teacher {
    public static void main(String[] args) {
        new Thread(new Receive(8086,"学生")).start();
        new Thread(new Send(7777,"localhost",5555)).start();
    }

}

public class Student {
    public static void main(String[] args) {
        new Thread(new Receive(5555,"老师")).start();
        new Thread(new Send(6666,"localhost",8086)).start();//第一个是发送端的IP，第二个是对方的接受端IP
    }

}

最终效果就是这样的

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