Bouncing Ball Program in Swing | Java.

Hello Guys!
Here We are going to learn that How to make a Bouncing Ball program in Swing. it is very is to  implement for you because the code of Bouncing Ball is written in easy way and it is given below :-

File Name :- BouncingBall.java

import java.awt.*;

import java.util.Formatter;

import javax.swing.*;

// Extends JPanel, so as to override the paintComponent() for custom rendering codes.

public class BouncingBall extends JPanel

{

   // Container box's width and height

   private static final int BOX_WIDTH = 800;

   private static final int BOX_HEIGHT = 500;

 

   // Ball's properties

   private float ballRadius = 100;            // Ball's radius

   private float ballX = ballRadius + 50;     // Ball's center (x, y)

   private float ballY = ballRadius + 20; 

   private float ballSpeedX = 3;              // Ball's speed for x and y

   private float ballSpeedY = 2;

 

   private static final int UPDATE_RATE = 30; // Number of refresh per second

 

   /* Constructor to create the UI components and init game objects. */

   public BouncingBall()

   {

      this.setPreferredSize(new Dimension(BOX_WIDTH, BOX_HEIGHT));

 

      // Start the ball bouncing (in its own thread)

      Thread gameThread = new Thread()
   {
            public void run()
      {
               while (true)
  {                                     // Execute one update step

                                                      // Calculate the ball's new position

                  ballX += ballSpeedX;

                  ballY += ballSpeedY;

                  // Check if the ball moves over the bounds

                  // If so, adjust the position and speed.

                  if (ballX - ballRadius < 0)
     {

                     ballSpeedX = -ballSpeedX; // Reflect along normal

                     ballX = ballRadius; // Re-position the ball at the edge

                     }

     else if (ballX + ballRadius > BOX_WIDTH)
     {

                     ballSpeedX = -ballSpeedX;

                     ballX = BOX_WIDTH - ballRadius;

                    }

                   // May cross both x and y bounds

                   if (ballY - ballRadius < 0)
      {

                      ballSpeedY = -ballSpeedY;

                      ballY = ballRadius;

                      }

     else if (ballY + ballRadius > BOX_HEIGHT)
      {

                      ballSpeedY = -ballSpeedY;

                      ballY = BOX_HEIGHT - ballRadius;

                      }

               // Refresh the display

               repaint();                                 // Callback paintComponent()
      
               try
           {                                      // Delay for timing control and give other threads a chance   

                  Thread.sleep(1000 / UPDATE_RATE);       // milliseconds

                   }

              catch (InterruptedException ex)

      {

       }

            }

         }

      };

      gameThread.start();  // Callback run()

   }

 

   /* Custom rendering codes for drawing the JPanel */

   public void paintComponent(Graphics g) {

      super.paintComponent(g);                  // Paint background

 

      // Draw the box

      g.setColor(Color.BLACK);

      g.fillRect(0, 0, BOX_WIDTH, BOX_HEIGHT);

 

      // Draw the ball

      g.setColor(Color.BLUE);

      g.fillOval((int) (ballX - ballRadius), (int) (ballY - ballRadius),(int)(2 * ballRadius), (int)(2 * ballRadius));

 

      // Display the ball's information

      g.setColor(Color.WHITE);

      g.setFont(new Font("Courier New", Font.PLAIN, 12));

      StringBuilder sb = new StringBuilder();

      Formatter formatter = new Formatter(sb);

      formatter.format("Ball @(%3.0f,%3.0f) Speed=(%2.0f,%2.0f)", ballX, ballY,ballSpeedX, ballSpeedY);

      g.drawString(sb.toString(), 20, 30);

   }

 

   /** main program (entry point) */

   public static void main(String[] args)

   {

      // Run GUI in the Event Dispatcher Thread (EDT) instead of main thread.

      javax.swing.SwingUtilities.invokeLater(new Runnable() {

         public void run()

   {

            // Set up main window (using Swing's Jframe)

            JFrame frame = new JFrame("A Bouncing Ball");

            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            frame.setContentPane(new BouncingBall());

            frame.pack();

            frame.setVisible(true);

         }

      });

   }

}

Output :-