用java制作放烟花的程序

下面是一个简单的 Java 程序，用于绘制放烟花的效果：

import java.awt.*;
import javax.swing.*;

public class Fireworks extends JPanel {

    private final int MAX_PARTICLES = 1000;  // 最大粒子数
    private Particle[] particles;  // 粒子数组
    private int numParticles;  // 当前粒子数

    public Fireworks() {
        setPreferredSize(new Dimension(500, 500));
        setBackground(Color.BLACK);
        particles = new Particle[MAX_PARTICLES];
        numParticles = 0;
    }

    public void addParticle(int x, int y, Color color) {
        if (numParticles < MAX_PARTICLES) {
            particles[numParticles++] = new Particle(x, y, color);
        }
    }

    public void update() {
        for (int i = 0; i < numParticles; i++) {
            if (!particles[i].update()) {
                particles[i] = particles[--numParticles];
                particles[numParticles] = null;
            }
        }
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        for (int i = 0; i < numParticles; i++) {
            particles[i].draw(g);
        }
    }

    public static void main(String[] args) throws InterruptedException {
        JFrame frame = new JFrame("Fireworks");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Fireworks fireworks = new Fireworks();
        frame.add(fireworks);
        frame.pack();
        frame.setVisible(true);

        while (true) {
            fireworks.addParticle((int) (Math.random() * fireworks.getWidth()),
                                   (int) (Math.random() * fireworks.getHeight()),
                                   new Color((int) (Math.random() * 256),
                                             (int) (Math.random() * 256),
                                             (int) (Math.random() * 256)));
            fireworks.update();
            fireworks.repaint();
            Thread.sleep(10);
        }
    }

    private static class Particle {

        private int x, y;  // 粒子位置
        private int dx, dy;  // 粒子速度
        private Color color;  // 粒子颜色
        private int life;  // 粒子寿命

        public Particle(int x, int y, Color color) {
            this.x = x;
            this.y = y;
            this.color = color;
            dx = (int) (Math.random() * 11) - 5;
            dy = (int) (Math.random() * 11) - 5;
            life = (int) (Math.random() * 51) + 50;
        }

        public boolean update() {
            x += dx;
            y += dy;
            life--;
            return life > 0;
        }

        public void draw(Graphics g) {
            g.setColor(color);
            g.fillOval(x, y, 5, 5);
        }
    }
}

这个程序使用了 Java 的 Swing 组件来绘制图形，通过重写 `paintComponent` 方法来绘制粒子效果。程序会不断地在窗口中添加粒子，并在每一帧更新所有粒子的位置和寿命，最后再绘制出来。