UDP chat implementation

UDP

Texting, no connection, need to know the address of the other party.

The sender

package com.zr.lesson03;

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

// No need to connect to the server
public class UdpSendDemo01 {
    public static void main(String[] args) throws Exception {
        // Create a socket
        DatagramSocket socket = new DatagramSocket();
        / / key
        String msg = "Hello?";
        // To whom
        InetAddress localhost = InetAddress.getByName("localhost");
        int port = 9090;
        DatagramPacket packet = new DatagramPacket(msg.getBytes(),0,msg.getBytes().length,localhost,port);

        / / send the packagesocket.send(packet); socket.close(); }}Copy the code

The receiving end

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 {
        // Open the port
        DatagramSocket socket = new DatagramSocket(9090);
        // Receive packets
        byte[] buffer = new byte[1024];
        DatagramPacket packet = new DatagramPacket(buffer, 0, buffer.length);
        // block reception
        socket.receive(packet);
        System.out.println(packet.getAddress());
        System.out.println(new String(packet.getData(),0,packet.getLength())); socket.close(); }}Copy the code

UDP chat implementation

Circular message sending

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);
        // Prepare data for reading from the console
        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(); }}Copy the code

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) {
            // Prepare to receive data
            byte[] bytes = new byte[1024];
            DatagramPacket packet = new DatagramPacket(bytes, 0, bytes.length);// Block to receive packages
            socket.receive(packet);
            // Disconnect the connection
            byte[] data = packet.getData();
            String receiveData = new String(data, 0, data.length);
            System.out.println(receiveData);
            if (receiveData.equals("bye")) {break; } } socket.close(); }}Copy the code

Online consultation: Two people can be the sender and both can be the receiver

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(a) {

        while (true) {
            try {
                // Prepare to receive data
                byte[] bytes = new byte[1024];
                DatagramPacket packet = new DatagramPacket(bytes, 0, bytes.length);// Block to receive packages
                socket.receive(packet);
                // Disconnect the connection
                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(); }}Copy the code

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);
            // Prepare data for reading from the console
            reader = new BufferedReader(new InputStreamReader(System.in));
        } catch(SocketException e) { e.printStackTrace(); }}@Override
    public void run(a) {

        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(); }}}Copy the code

package com.zr.udpChat;

public class TalkStudent {
    public static void main(String[] args) {
        // Start two threads
        new Thread(new TalkSend(7777."localhost".9999)).start();
        new Thread(new TalkReceive(8888."Teacher")).start(); }}Copy the code

package com.zr.udpChat;

public class TalkTeacher {
    public static void main(String[] args) {
        // Start two threads
        new Thread(new TalkSend(6666."localhost".8888)).start();
        new Thread(new TalkReceive(9999."Students")).start(); }}Copy the code

Results: