Want to show firework in swing panel, here it is a way to show something like above picture in java swing. It is done by extending JPanel class and overriding its paintComponent method.  To know what it exactly looks like, give it a try and run once. Let me know your feedback. 🙂

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Stroke;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javax.swing.JPanel;
import javax.swing.Timer;

/**
 * Panel in which you can see fireworks.
 */
public class FireworkPanel extends JPanel {

private static final long serialVersionUID = 5053650234847311814L;
 private Timer timer;
 private static final int DELAY = 10, DIVIDER = 180, MULTIPLY_FACTOR = 36, LINE_LENGTH = 2, FIREWORK_RADIUS = 75;
 private static final int ARRAY_LENGTH = 5;
 private static int X_CENTER[] = new int[ARRAY_LENGTH], Y_CENTER[] = new int[ARRAY_LENGTH];
 private static Color colors[] = new Color[ARRAY_LENGTH];
 private static final double PI = 3.14159;
 int x[] = new int[10],y[] = new int[10];
 private int x1, moveX, index, color_index;
 List<Integer> xx = new ArrayList<Integer>();
 List<Integer> yy = new ArrayList<Integer>();

public FireworkPanel() {
      x1 = index = color_index = 0;
      moveX = 3;
      timer = new Timer(DELAY, new MyChangeListener());
      timer.start();
      X_CENTER[0]=100;
      Y_CENTER[0]=100;

      X_CENTER[1]=200;
      Y_CENTER[1]=200;

      X_CENTER[2]=300;
      Y_CENTER[2]=300;

      X_CENTER[3]=300;
      Y_CENTER[3]=100;

      X_CENTER[4]=100;
      Y_CENTER[4]=300;

      colors[0] = Color.ORANGE;
      colors[1] = Color.BLUE;
      colors[2] = Color.CYAN;
      colors[3] = Color.RED;
      colors[4] = Color.PINK;

      setBackground(Color.black);
 }

@Override
protected void paintComponent(Graphics g) {
     super.paintComponent(g);
     Graphics2D graphics2d = (Graphics2D) g;
     Stroke stroke = new BasicStroke(3, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND, 5, new float[]{9},  0);
     graphics2d.setStroke(stroke);
     graphics2d.setColor(colors[color_index]);
     for (int i = 0; i < xx.size(); i++) {
          graphics2d.drawLine(xx.get(i),yy.get(i),xx.get(i)+LINE_LENGTH,yy.get(i)+LINE_LENGTH);
     }
}

class MyChangeListener implements ActionListener {
@Override
public void actionPerformed(ActionEvent arg0) {
     x1 += moveX;
     if (x1 == 0 || x1 >= FIREWORK_RADIUS) {
          x1=0;
          Random random = new Random();
          index = random.nextInt(ARRAY_LENGTH);
          color_index = random.nextInt(ARRAY_LENGTH);
     }
     xx.clear();
     yy.clear();
     for (int i = 0; i < 10; i++) {
         xx.add((int) (X_CENTER[index] + x1 * Math.cos((MULTIPLY_FACTOR * i * PI) / DIVIDER)));
         yy.add((int) (Y_CENTER[index] + x1 * Math.sin((MULTIPLY_FACTOR * i * PI) / DIVIDER)));
     }
     repaint();
   }
}
}

And here is how to test it:

 JFrame frame = new JFrame("Fireworks");
 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 frame.setSize(400, 425);
 frame.setResizable(false);
 frame.setUndecorated(true);
 frame.getRootPane().setWindowDecorationStyle(JRootPane.FRAME);
 frame.setLayout(new BorderLayout());
 JPanel panel = new JPanel(new FlowLayout(FlowLayout.CENTER));
 JLabel jLabel = new JLabel("Fireworks By Harry Joy");
 jLabel.setFont(new Font("Tahoma", Font.PLAIN, 14));
 panel.add(jLabel);
 frame.getContentPane().add(panel, BorderLayout.NORTH);
 frame.getContentPane().add(new FireworkPanel(), BorderLayout.CENTER);
 frame.setVisible(true);

Hope you like it. 😀

• Java
• Swing