用Java编写一个贪吃蛇游戏

好的，下面是一个简单的Java贪吃蛇游戏示例代码：

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

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

public class SnakeGame extends JPanel implements Runnable, KeyListener {

    private static final long serialVersionUID = 1L;
    public static final int WIDTH = 500;
    public static final int HEIGHT = 500;
    public static final int DOT_SIZE = 10;
    private static final int INITIAL_SNAKE_SIZE = 10;

    private List<Point> snake = new ArrayList<Point>();
    private int direction = KeyEvent.VK_RIGHT;
    private Point food = new Point(0, 0);
    private Random random = new Random();
    private boolean running = true;

    public SnakeGame() {
        JFrame frame = new JFrame("Snake Game");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(WIDTH, HEIGHT);
        frame.setResizable(false);
        frame.add(this);
        frame.addKeyListener(this);
        frame.setVisible(true);

        for (int i = 0; i < INITIAL_SNAKE_SIZE; i++) {
            snake.add(new Point(50 - i * DOT_SIZE, 50));
        }

        spawnFood();
    }

    private void spawnFood() {
        int x = random.nextInt(WIDTH / DOT_SIZE) * DOT_SIZE;
        int y = random.nextInt(HEIGHT / DOT_SIZE) * DOT_SIZE;
        food.setLocation(x, y);
    }

    private void move() {
        Point head = snake.get(0);
        Point newHead = new Point(head);

        switch (direction) {
        case KeyEvent.VK_LEFT:
            newHead.x -= DOT_SIZE;
            break;
        case KeyEvent.VK_RIGHT:
            newHead.x += DOT_SIZE;
            break;
        case KeyEvent.VK_UP:
            newHead.y -= DOT_SIZE;
            break;
        case KeyEvent.VK_DOWN:
            newHead.y += DOT_SIZE;
            break;
        }

        if (newHead.equals(food)) {
            snake.add(0, newHead);
            spawnFood();
        } else {
            snake.remove(snake.size() - 1);
            snake.add(0, newHead);
        }

        if (snakeCollidesWithItself()) {
            running = false;
        }

        if (snakeHitsWall()) {
            running = false;
        }
    }

    private boolean snakeCollidesWithItself() {
        Point head = snake.get(0);
        for (int i = 1; i < snake.size(); i++) {
            Point part = snake.get(i);
            if (head.equals(part)) {
                return true;
            }
        }
        return false;
    }

    private boolean snakeHitsWall() {
        Point head = snake.get(0);
        if (head.x < 0 || head.x >= WIDTH || head.y < 0 || head.y >= HEIGHT) {
            return true;
        }
        return false;
    }

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

        g.setColor(Color.GREEN);
        for (Point part : snake) {
            g.fillRect(part.x, part.y, DOT_SIZE, DOT_SIZE);
        }

        g.setColor(Color.RED);
        g.fillRect(food.x, food.y, DOT_SIZE, DOT_SIZE);
    }

    public static void main(String[] args) {
        new SnakeGame().start();
    }

    public void start() {
        Thread t = new Thread(this);
        t.start();
    }

    @Override