[网络协议] JAVA网络编程：基于UDP协议的在线聊天器

package JAVANET;//当前类所在的包

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

public class UDPSendThread implements Runnable{
    DatagramSocket socket = null;
    BufferedReader reader = null;

    private int fromPort;
    private String toIp;
    private int toPort;
    public UDPSendThread(int fromPort, String toIp, int toPort) {
        this.fromPort = fromPort;
        this.toIp = toIp;
        this.toPort = toPort;

        try {
            socket = new DatagramSocket(fromPort);
            reader = new BufferedReader(new InputStreamReader(System.in));
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        while (true){
            try {
                String data = reader.readLine();
                byte[] datas = data.getBytes();
                DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress(this.toIp,this.toPort));
                socket.send(packet);
                if (data.equals("bye")){
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        socket.close();

    }
}

2.2?接受消息线程类

package JAVANET;

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

public class UDPRevdThread implements Runnable{
    DatagramSocket socket = null;
    private int port;
    private String msgFrom;

    public UDPRevdThread(int port,String msgFrom) {
        this.port = port;
        this.msgFrom = msgFrom;
        try {
            socket = new DatagramSocket(port);
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        // 准备接收包裹
        while (true){
            try {
                byte[] container = new byte[1024];
                DatagramPacket packet = new DatagramPacket(container, 0, container.length);
                socket.receive(packet); // 阻塞式接收包裹
                // 断开连接
                byte[] data = packet.getData();
                String receiveData = new String(data, 0,packet.getLength());
                System.out.println(msgFrom+":"+receiveData);
                if (receiveData.equals("bye")){
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        socket.close();
    }
}

2.3?通信方A

package JAVANET;

public class UDPStudent {
    public static void main(String[] args) {
         /*开启发送消息线程
         *5001表示：消息从本机5001端口发送出去
         *192.168.101.78表示：目的主机的IP
         *5003表示：目的主机的接收端口号
         * */
        new Thread(new UDPSendThread(5001,"192.168.101.78",5003)).start();
        /*开启接受消息线程：
        *5002：本机接受消息的端口，
        *设置接受到的消息，来自于“学生”，相当于备注
        */
        new Thread(new UDPRevdThread(5002,"学生")).start();
    }
}

2.4?通信方B

package JAVANET;

public class UDPTeacher {
    public static void main(String[] args) {
         /*开启发送消息线程
         *5000表示：消息从本机5000端口发送出去
         *192.168.101.78表示：目的主机的IP
         *5002表示：目的主机的接收端口号
         * */
        new Thread(new UDPSendThread(5000,"192.168.101.12",5002)).start();
        /*开启接受消息线程：
        *5003：本机接受消息的端口，
        *设置接受到的消息，来自于“老师”，相当于备注
        */
        new Thread(new UDPRevdThread(5003,"老师")).start();
    }
}