Java Network Programming to Realize Multi thread Chat

This article example for everyone to share Java network programming to achieve multi-threaded chat specific code, for your reference, the specific content is as follows

If the chat program is single-threaded, it will cause no one to say only one sentence, and after saying it, they must wait for another person's reply before saying the second sentence. Both sending and receiving are in the main thread and cannot be carried out at the same time.

Solution:

Distribute incoming and outgoing to two different threads

1. SendThread Send Message Thread
2. RecieveThread Accept Message Thread
3. Once Server1 receives a connection, it starts two sending and receiving threads
4. Once the connection is established, Client 1 starts two sending and receiving threads

Multithreaded chat

1 SendThread

package socket;

import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;
import java.util.Scanner;

public class SendThread extends Thread {
    private Socket s;
    public SendThread(Socket s) {
        this.s = s;
    }
    @Override
    public void run() {
        try {
            OutputStream os = s.getOutputStream();
            DataOutputStream dos = new DataOutputStream(os);
            while(true){
                Scanner sc = new Scanner(System.in);
                String str = sc.next();
                dos.writeUTF(str);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

2 RecieveThread

package socket;

import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.Socket;

public class RecieveThread extends Thread {
    private Socket s;
    public RecieveThread(Socket s) {
        this.s = s;
    }
    @Override
    public void run() {
        InputStream is = null;
        try {
            is = s.getInputStream();
            DataInputStream dis = new DataInputStream(is);
            while(true){
                String msg = dis.readUTF();
                System.out.println(msg);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

3 Server

package socket;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
    public static void main(String[] args) {
        try {
            ServerSocket ss = new ServerSocket(8888);
            System.out.println(" Listening port number: 8888");
            Socket s = ss.accept();

            new SendThread(s).start();
            new RecieveThread(s).start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

4 Client

package socket;

import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

public class Client {
    public static void main(String[] args) {
        try {
            Socket s = new Socket("127.0.0.1", 8888);

            new SendThread(s).start();
            new RecieveThread(s).start();
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Simple dialog box

Server

package socket;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.ServerSocket;
import java.net.Socket;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class GUIServer {

    public static void main(String[] args) throws Exception {

        JFrame f = new JFrame();
        f.setTitle("server");

        f.setSize(400, 300);
        f.setLocation(100, 200);
        f.setLayout(null);

        JButton b = new JButton("send");
        b.setBounds(10, 10, 80, 30);
        f.add(b);

        final JTextField tf = new JTextField();
        tf.setBounds(10, 110, 80, 30);
        f.add(tf);

        final JTextArea ta = new JTextArea();
        ta.setBounds(110,10, 200, 300);
        f.add(ta);

        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);

        ServerSocket ss = new ServerSocket(8888);

        System.out.println("listenning on port:8888");
        final Socket s =  ss.accept();        
        new Thread() {
            public void run() {
                while (true) {
                    try {
                        DataInputStream dis = new DataInputStream(
                                s.getInputStream());
                        String text = dis.readUTF();
                        ta.append(text+"\r\n");
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

            }
        }.start();

        b.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                String text = tf.getText();
                ta.append(text+"\r\n");

                try {
                    DataOutputStream dos = new DataOutputStream(
                            s.getOutputStream());
                    dos.writeUTF(text);
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        });

    }
}

Client

package socket;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.Socket;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class GUIClient {

    public static void main(String[] args) throws Exception {

        JFrame f = new JFrame();
        f.setTitle("client");

        f.setSize(400, 300);
        f.setLocation(600, 200);
        f.setLayout(null);

        JButton b = new JButton("send");
        b.setBounds(10, 10, 80, 30);
        f.add(b);

        final JTextField tf = new JTextField();
        tf.setBounds(10, 110, 80, 30);
        f.add(tf);

        final JTextArea ta = new JTextArea();
        ta.setBounds(110,10, 200, 300);
        f.add(ta);

        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);

        final Socket s = new Socket("127.0.0.1", 8888);

        new Thread() {
            public void run() {
                while (true) {
                    try {
                        DataInputStream dis = new DataInputStream(
                                s.getInputStream());
                        String text = dis.readUTF();
                        ta.append(text+"\r\n");
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }

            }
        }.start();

        b.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {

                String text = tf.getText();
                ta.append(text+"\r\n");

                try {
                    DataOutputStream dos = new DataOutputStream(
                            s.getOutputStream());
                    dos.writeUTF(text);
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
            }
        });

    }
}