Create a drawing dot gui application in java

Problem:

Create a drawing dot java gui application.

Solution:

//***************DrawingDotFrame.java************************/
import javax.swing.JFrame;

public class DrawingDotFrame {

 
  public static void main(String[] args) {
   
   JFrame frame = new JFrame("Drawing Dot");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.getContentPane().add(new DrawingDotPanel());
   frame.pack();
   frame.setVisible(true);
   frame.setResizable(false);
   frame.setLocationRelativeTo(null);
  }
}
//***************DrawingDotPanel.java************************/
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;

import javax.swing.JPanel;

public class DrawingDotPanel extends JPanel {

 private ArrayList<Point> points;
 private final int WIDTH = 400, HEIGHT = 400;
 private final int Radius = 3;
 
 public DrawingDotPanel() {

  
  points = new ArrayList<>();
  
  addMouseListener(new DotsListener());
  
  
  setPreferredSize(new Dimension(WIDTH,HEIGHT));
  setBackground(Color.BLACK);
 }
 @Override
 protected void paintComponent(Graphics g) {
  super.paintComponent(g);
  g.setColor(Color.GREEN);
  
  for(Point p : points)
  g.fillOval(p.x-Radius, p.y-Radius, 2*Radius, 2*Radius); 
  g.drawString("Count: " + points.size(), 5,15);
  
 }
 private class DotsListener implements MouseListener {

  @Override
  public void mouseClicked(MouseEvent arg0) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void mouseEntered(MouseEvent arg0) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void mouseExited(MouseEvent arg0) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void mousePressed(MouseEvent arg0) {
   // TODO Auto-generated method stub
   
   points.add(arg0.getPoint());
   repaint();
  }

  @Override
  public void mouseReleased(MouseEvent arg0) {
   // TODO Auto-generated method stub
   
  }
  
 }
}