Java实现UDP多线程在线咨询

1.发送的线程

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;

//发送线程
public class TalkSend implements Runnable {
    DatagramSocket socket = null;
    BufferedReader reader = null;
    private int formPort; //自身端口
    private String toIP; //发送到的IP
    private int toPort; //发送到的端口

    public TalkSend(int formPort, String toIP, int toPort) {
        this.formPort = formPort;
        this.toIP = toIP;
        this.toPort = toPort;

        try {
            socket = new DatagramSocket(formPort);
            reader = new BufferedReader(new InputStreamReader(System.in)); //获取控制台输入
        } catch (SocketException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        while(true) {
            try {
                String data = reader.readLine(); //获取到的数据
                byte[] datas = data.getBytes(); //转换为需要的字节数组
                //将数据打包成包
                DatagramPacket packet = new DatagramPacket(datas,0, datas.length,new InetSocketAddress(this.toIP,this.toPort));
                socket.send(packet); //发送包
                //退出指令
                if(packet.equals("bye")){
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        socket.close();
    }
}

2.接收的线程

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
//接收线程
public class TalkReceive implements Runnable {

    DatagramSocket socket = null; //与发送端的socket为同一个，实现通信
    private int port;
    private String msgFrom; //标志信息来源

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

    @Override
    public void run() {
        while (true){

            try {
                byte[] container = new byte[1024];
                DatagramPacket packet = new DatagramPacket(container, 0, container.length);
                socket.receive(packet);//接收数据

                byte[] data = packet.getData();
                String receiveData = new String(data, 0, data.length);

                System.out.println(msgFrom+":"+receiveData);

                if(receiveData.equals("bye")){
                    break;
                }
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
        socket.close();
    }
}

3.模拟学生端

//模拟学生
public class TalkStudent {
    public static void main(String[] args) {
        new Thread(new TalkSend(7777, "localhost", 9999)).start();
        new Thread(new TalkReceive(8888, "老师")).start();
    }
}

4.模拟老师端

//模拟老师
public class TalkTeacher {
    public static void main(String[] args) {
        new Thread(new TalkSend(5555, "localhost", 8888)).start();
        new Thread(new TalkReceive(9999, "学生")).start();
    }
}

5.截图

学生端：

老师端：

6.总结

首先创建一个发送线程，里面定义要发送到的IP地址和端口，再创建一个DatagramSocket来进行通信，创建一个BufferReader(new InputStreamReader(System.in))来获取控制台的输入的数据，将获取到的数据打包进行发送。之后创建一个接收线程，里面定义自身的端口即可，再创建一个和发送端一样的DatagramSocket来进行通信，接收数据进行打印输出即可。最后模拟学生端和老师端，创建这两个线程来进行通信。学生发送线程到的端口是老师的接收端口，老师发送的端口是学生的接收端口，这样才能互相通信。