UDP聊天实现

UDP

发短信，不用连接，需要知道对方地址。

发送端

package com.zr.lesson03;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;

//不需要连接服务器
public class UdpSendDemo01 {
    public static void main(String[] args) throws Exception {
        //建立一个socket
        DatagramSocket socket = new DatagramSocket();
        //键个包
        String msg = "你好啊";
        //发送给谁
        InetAddress localhost = InetAddress.getByName("localhost");
        int port = 9090;
        DatagramPacket packet = new DatagramPacket(msg.getBytes(),0,msg.getBytes().length,localhost,port);

        //发送包
        socket.send(packet);

        socket.close();
    }
}

接收端

package com.zr.lesson03;

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

public class UdpRecelveDemo01 {
    public static void main(String[] args) throws Exception {
        //开放端口
        DatagramSocket socket = new DatagramSocket(9090);
        //接收数据包
        byte[] buffer = new byte[1024];
        DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);
        //阻塞接收
        socket.receive(packet);
        System.out.println(packet.getAddress());
        System.out.println(new String(packet.getData(),0,packet.getLength()));
        socket.close();
    }
}

UDP聊天实现

循环发送消息

package com.zr.udpChat;

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

public class UdpSenderDemo01 {
    public static void main(String[] args) throws Exception {
        DatagramSocket socket = new DatagramSocket(8888);
        //准备数据 从控制台读取
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            String data = reader.readLine();
            byte[] datas = data.getBytes();

            DatagramPacket packet = new DatagramPacket(datas,0,datas.length,new InetSocketAddress("localhost",6666));
            socket.send(packet);
            if (data.equals("bye")){
                break;
            }
        }
        socket.close();
        reader.close();
    }
}

package com.zr.udpChat;

import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class UdpReceiveDemo01 {
    public static void main(String[] args) throws Exception{
        DatagramSocket socket = new DatagramSocket(6666);
        while (true) {
            //准备接收数据
            byte[] bytes = new byte[1024];
            DatagramPacket packet = new DatagramPacket(bytes, 0, bytes.length);//阻塞式接收包裹
            socket.receive(packet);
            //断开连接
            byte[] data = packet.getData();
            String receiveData = new String(data, 0, data.length);
            System.out.println(receiveData);
            if (receiveData.equals("bye")){
                break;
            }
        }
        socket.close();
    }
}

在线咨询：两个人都可以是发送方，都可以是接收方

package com.zr.udpChat;

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

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

    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 {
                //准备接收数据
                byte[] bytes = new byte[1024];
                DatagramPacket packet = new DatagramPacket(bytes, 0, bytes.length);//阻塞式接收包裹
                socket.receive(packet);
                //断开连接
                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();
    }
}

package com.zr.udpChat;

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 TalkSend implements Runnable{
    DatagramSocket socket = null;
    BufferedReader reader = null;

    private int fromPort;
    private String toIP;
    private int toPort;

    public TalkSend(int fromPort, String toIP, int toPort) {
        this.fromPort = fromPort;
        this.toIP = toIP;
        this.toPort = toPort;
        try {
            socket = new DatagramSocket(fromPort);
            //准备数据 从控制台读取
            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();
        try {
            reader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

package com.zr.udpChat;

public class TalkStudent {
    public static void main(String[] args) {
        //开启两个线程
        new Thread(new TalkSend(7777,"localhost",9999)).start();
        new Thread(new TalkReceive(8888,"老师")).start();
    }
}

package com.zr.udpChat;

public class TalkTeacher {
    public static void main(String[] args) {
        //开启两个线程
        new Thread(new TalkSend(6666,"localhost",8888)).start();
        new Thread(new TalkReceive(9999,"学生")).start();
    }
}

结果：