java编写一个贪吃蛇游戏，具有计分功能

好的，下面是一个简单的 Java 贪吃蛇游戏，具有计分功能：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.ArrayList;
import java.util.Random;

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

public class SnakeGame implements ActionListener, KeyListener {

    public static final int WIDTH = 800, HEIGHT = 800;
    public static final int UNIT_SIZE = 25;
    public static final int GAME_UNITS = (WIDTH * HEIGHT) / UNIT_SIZE;
    public static final int DELAY = 75;

    private final int[] x = new int[GAME_UNITS];
    private final int[] y = new int[GAME_UNITS];

    private int bodyParts = 6;
    private int applesEaten = 0;
    private int appleX;
    private int appleY;
    private char direction = 'R';

    private boolean running = false;

    private Timer timer;
    private Random random;

    public SnakeGame() {
        JFrame frame = new JFrame("Snake Game");
        JPanel panel = new JPanel() {
            @Override
            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                draw(g);
            }
        };

        panel.setPreferredSize(new Dimension(WIDTH, HEIGHT));
        panel.setBackground(Color.BLACK);
        panel.setFocusable(true);
        panel.addKeyListener(this);

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);
        frame.add(panel);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);

        startGame();
    }

    private void startGame() {
        x[0] = 0;
        y[0] = 0;

        random = new Random();
        appleX = random.nextInt(WIDTH / UNIT_SIZE) * UNIT_SIZE;
        appleY = random.nextInt(HEIGHT / UNIT_SIZE) * UNIT_SIZE;

        timer = new Timer(DELAY, this);
        timer.start();

        running = true;
    }

    private void draw(Graphics g) {
        if (running) {
            g.setColor(Color.RED);
            g.fillOval(appleX, appleY, UNIT_SIZE, UNIT_SIZE);

            for (int i = 0; i < bodyParts; i++) {
                if (i == 0) {
                    g.setColor(Color.GREEN);
                } else {
                    g.setColor(Color.YELLOW);
                }
                g.fillRect(x[i], y[i], UNIT_SIZE, UNIT_SIZE);
            }

            g.setColor(Color.WHITE);
            g.drawString("Score: " + applesEaten, 10, 20);
        } else {
            gameOver(g);
        }
    }

    private void move() {
        for (int i = bodyParts; i > 0; i--) {
            x[i] = x[i - 1];
            y[i] = y[i - 1];
        }

        switch (direction) {
            case 'U':
                y[0] = y[0] - UNIT_SIZE;
                break;
            case 'D':
                y[0] = y[0] + UNIT_SIZE;
                break;
            case 'L':
                x[0] = x[0] - UNIT_SIZE;
                break;
            case 'R':
                x[0] = x[0] + UNIT_SIZE;
                break;
        }
    }

    private void checkApple() {
        if (x[0] == appleX && y[0] == appleY) {
            bodyParts++;
            applesEaten++;
            appleX = random.nextInt(WIDTH / UNIT_SIZE) * UNIT_SIZE;
            appleY = random.nextInt(HEIGHT / UNIT_SIZE) * UNIT_SIZE;
        }
    }

    private void checkCollisions() {
        for (int i = bodyParts; i > 0; i--) {
            if (x[0] == x[i] && y[0] == y[i]) {
                running = false;
                break;
            }
        }

        if (x[0] < 0 || x[0] > WIDTH - UNIT_SIZE || y[0] < 0 || y[0] > HEIGHT - UNIT_SIZE) {
            running = false;
        }

        if (!running) {
            timer.stop();
        }
    }

    private void gameOver(Graphics g) {
        g.setColor(Color.WHITE);
        g.drawString("Game Over", WIDTH / 2 - 30, HEIGHT / 2 - 10);
        g.drawString("Score: " + applesEaten, WIDTH / 2 - 30, HEIGHT / 2 + 10);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (running) {
            move();
            checkApple();
            checkCollisions();
        }
        panel.repaint();
    }

    @Override
    public void keyPressed(KeyEvent e) {
        switch (e.getKeyCode()) {
            case KeyEvent.VK_UP:
                if (direction != 'D') {
                    direction = 'U';
                }
                break;
            case KeyEvent.VK_DOWN:
                if (direction != 'U') {
                    direction = 'D';
                }
                break;
            case KeyEvent.VK_LEFT:
                if (direction != 'R') {
                    direction = 'L';
                }
                break;
            case KeyEvent.VK_RIGHT:
                if (direction != 'L') {
                    direction = 'R';
                }
                break;
        }
    }

    @Override
    public void keyReleased(KeyEvent e) {}

    @Override
    public void keyTyped(KeyEvent e) {}
    
    public static void main(String[] args) {
        new SnakeGame();
    }

}

这个游戏使用了 Java Swing 组件来创建窗口和绘制游戏。在游戏过程中，使用方向键控制蛇的移动方向，当蛇头碰到边界或自身时游戏结束。每当蛇吃掉一个苹果时，计分器会加一。