用Java写一个放烟花的代码

以下是一个简单的 Java 代码，用于放烟花：

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Fireworks extends JFrame {

    private static final long serialVersionUID = 1L;
    private List<Particle> particles = new ArrayList<Particle>();
    private Random random = new Random();
    private int counter = 0;

    public Fireworks() {
        setTitle("Fireworks");
        setSize(800, 600);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new JPanel() {
            private static final long serialVersionUID = 1L;

            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                for (Particle particle : particles) {
                    particle.draw(g);
                }
            }
        };
        setContentPane(panel);
        setVisible(true);
        run();
    }

    private void run() {
        while (true) {
            if (counter++ % 10 == 0) {
                if (random.nextInt(100) < 30) {
                    particles.add(new Firework(random.nextInt(getWidth()), getHeight() - 1));
                }
            }
            for (Particle particle : particles) {
                particle.move();
            }
            particles.removeIf(p -> p.isDead());
            repaint();
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    private interface Particle {
        void move();
        void draw(Graphics g);
        boolean isDead();
    }

    private class Firework implements Particle {

        private int x;
        private int y;
        private int age;
        private int maxAge;
        private List<Spark> sparks = new ArrayList<Spark>();

        public Firework(int x, int y) {
            this.x = x;
            this.y = y;
            maxAge = random.nextInt(60) + 60;
        }

        @Override
        public void move() {
            if (age++ < maxAge) {
                y--;
            } else {
                for (int i = 0; i < 20; i++) {
                    sparks.add(new Spark(x, y));
                }
            }
            for (Spark spark : sparks) {
                spark.move();
            }
        }

        @Override
        public void draw(Graphics g) {
            if (age < maxAge) {
                g.setColor(Color.WHITE);
                g.drawLine(x, y, x, y);
            } else {
                for (Spark spark : sparks) {
                    spark.draw(g);
                }
            }
        }

        @Override
        public boolean isDead() {
            return age > maxAge && sparks.isEmpty();
        }
    }

    private class Spark implements Particle {

        private Point position;
        private Point velocity;
        private int age;
        private int maxAge;
        private Color color;

        public Spark(int x, int y) {
            position = new Point(x, y);
            velocity = new Point(random.nextInt(5) - 2, random.nextInt(5) - 8);
            maxAge = random.nextInt(20) + 20;
            color = new Color(random.nextInt(255), random.nextInt(255), random.nextInt(255));
        }

        @Override
        public void move() {
            position.translate(velocity.x, velocity.y);
            velocity.translate(0, 1);
            age++;
        }

        @Override
        public void draw(Graphics g) {
            g.setColor(color);
            g.drawLine(position.x, position.y, position.x, position.y);
        }

        @Override
        public boolean isDead() {
            return age > maxAge;
        }
    }

    public static void main(String[] args) {
        new Fireworks();
    }
}

这个程序使用 Java Swing 绘制烟花。它创建了一个 `Fireworks` 类来启动程序，该类继承自 `JFrame`，并在其中创建一个 `JPanel` 作为内容面板。这个程序在一个无限循环中运行，每隔一段时间就会发射一个烟花。烟花会发射出许多火花，火花会向上飞，然后开始下落，最终消失。