Zero Exception – Java, Spring Boot & System Design Tutorials

Write a Java program Design a screen with two buttons start thread and stop thread. Clicking on start it should start printing "Thread running" until stop button is pressed.

Program:

import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class ThreadRun extends JFrame implements Runnable, ActionListener {
    int i,j;
    String str, msg = "Thread running";
    Thread t;
    JButton btnStart, btnStop;
    JPanel panel;

    public ThreadRun() {
        Container c = getContentPane();
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        t = new Thread(this);
        panel = new JPanel();
        btnStart = new JButton("Start Thread");
        btnStop = new JButton("Stop Thread");
        panel.add(btnStart);
        panel.add(btnStop);
        btnStart.addActionListener(this);
        btnStop.addActionListener(this);
        c.add(panel);
        setSize(500,600);
        setVisible(true);
        j=80;
    }

    public void run(){
        try {
            while(true){
                repaint();
                t.sleep(500);
            }
        }catch(InterruptedException e){
            System.out.println(e);
        }
    }

    public void actionPerformed(ActionEvent ae){
        str = ae.getActionCommand();
        if(str.equals("Start Thread")){
            t.start();
        } else if(str.equals("Stop Thread")){
            t.stop();
        }
    }

    public void update(Graphics g){
        repaint();
    }

    public void paint(Graphics g){
        g.drawString(msg,50,j);
        j+=20;
    }
    
    public static void main(String args[]){
        ThreadRun tr = new ThreadRun();
    }
}