How to add a countdown code to a Java app?

Question

I've recently got a project in school.

• Create a Java GUI with an image as background and some textbox.

• the first textbox is just a text that says: Lunch break at 1pm.

• the second textbox is a countdown timer. This timer should appear 5 minutes before the end of the upcoming break, which counts down from 5:00 to 0:00 minutes every second. When reaching 0:00, the timer should respond to a text (e.g. "The Presentation will start shortly ").

• Image as a background: done

• Text that says: Lunch break at 1pm: done

• Countdown: I'm stuck at this point. I program a countdown timer first on the console. But I really don't know how to include this countdown to a Java GUI.

Do you have any suggestions?

This is my code for the background:

import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Toolkit;
import javax.swing.JPanel;

import javax.swing.*;

public class Bildhintergrund extends JFrame{


    
    //Background
        public Bildhintergrund () {
        setTitle(" Bildhintergrund");
        setSize(Toolkit.getDefaultToolkit().getScreenSize());
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
        setLayout(new BorderLayout());
        setContentPane(new JLabel(new ImageIcon("/path/to/bild.jpg")));
        setLayout(new FlowLayout());
        JLabel background = new JLabel();
                add(background);
        
        //Text
    
        JLabel text = new JLabel() {
              public void paintComponent(Graphics g) {
                super.paintComponent(g);
                
              }
            };
        ;
            JPanel panel = new JPanel();
            Dimension size = text.getPreferredSize();
            getContentPane().add( text );
            text.setFont(text.getFont().deriveFont((float) 58));
            text.setText("Lunch break at 1pm");
            /*text.setAlignmentX(0);
            text.setAlignmentY(0);*/
            text.setBounds(300, 300, size.width, size.height);
            panel.add(text);
            panel.setLayout(null);
            add(text);
        }
        public static void main(String[] args) {
    new Bildhintergrund();
}
        }

This is my code for the countdown:

  {
    /*int Time = 5;
    String time;
    int seconds;
    int minutes;*/
    
    int timet= Time * 60; // Convert to seconds
    long delay = timet * 1000;

    do
    {
      minutes = timet / 60;
      seconds = timet % 60;
      time = minutes + ":"  + seconds;
  
    
      System.out.println(GetTimer());
   
      Thread.sleep(1000);
      timet = timet - 1;
      delay = delay - 1000;

    }
    while (delay != 0);
    System.out.println("Another topic will follow");
  
  }
  public static  String GetTimer()
  {
    
      
    return  time;
  }
}

Answer 1

You can use javax.swing.Timer like this example:

javax.swing.Timer timer = new javax.swing.Timer(1000/*timer delay between calling ActionListener.actionPerformed(ActionEvent e) (in milliseconds)*/, new ActionListener() {
            
            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("Second over!!!");
                //put your code here
            }
        });
        timer.setRepeats(true);//makes timer repeats forever (or until call timer.stop() method)
        timer.start();