用java编写一个放烟花

以下是一个简单的Java代码示例，用于放烟花：

import java.awt.Color;
import java.awt.Graphics;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class Fireworks extends JPanel implements Runnable {
    private static final long serialVersionUID = 1L;

    private int xPos;
    private int yPos;
    private int[] xPoints = new int[5];
    private int[] yPoints = new int[5];
    private Color color;
    private boolean exploded;
    private Random random;

    public Fireworks() {
        random = new Random();
        xPos = random.nextInt(800);
        yPos = random.nextInt(600);
        color = new Color(random.nextInt(256), random.nextInt(256), random.nextInt(256));
        exploded = false;

        for (int i = 0; i < 5; i++) {
            xPoints[i] = xPos;
            yPoints[i] = yPos;
        }
    }

    public void run() {
        while (!exploded) {
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            yPos += random.nextInt(5) + 1;

            if (yPos > 500) {
                explode();
            }

            repaint();
        }
    }

    private void explode() {
        exploded = true;

        for (int i = 0; i < 5; i++) {
            xPoints[i] = xPos;
            yPoints[i] = yPos;

            Thread thread = new Thread(new Explosion(xPoints[i], yPoints[i], color));
            thread.start();

            try {
                thread.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        g.setColor(color);
        g.fillOval(xPos, yPos, 10, 10);
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Fireworks");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(800, 600);

        JPanel panel = new JPanel();
        panel.setLayout(null);

        for (int i = 0; i < 20; i++) {
            Fireworks fireworks = new Fireworks();
            fireworks.setBounds(0, 0, 800, 600);
            panel.add(fireworks);

            Thread thread = new Thread(fireworks);
            thread.start();
        }

        frame.add(panel);
        frame.setVisible(true);
    }
}

class Explosion implements Runnable {
    private int xPos;
    private int yPos;
    private Color color;
    private Random random;

    public Explosion(int xPos, int yPos, Color color) {
        this.xPos = xPos;
        this.yPos = yPos;
        this.color = color;
        random = new Random();
    }

    public void run() {
        Graphics g = Fireworks.getGraphics();

        for (int i = 0; i < 50; i++) {
            int x = xPos + random.nextInt(101) - 50;
            int y = yPos + random.nextInt(101) - 50;

            g.setColor(color);
            g.fillOval(x, y, 10, 10);

            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

这个代码会创建一个显示烟花的窗口。在窗口中，会同时放置多个烟花，并且每个烟花都会按照一定的速度向下移动，直到达到一定高度时就会爆炸成多个小烟花。小烟花会随机生成，并且会以一定的速度向四周扩散。