用java写一个贪吃蛇小游戏

好的，下面是一个简单的贪吃蛇小游戏的Java代码示例：

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

public class SnakeGame extends JFrame implements ActionListener {
    private final int WIDTH = 300;
    private final int HEIGHT = 300;

    private Timer timer;
    private Snake snake;
    private Food food;

    public SnakeGame() {
        setTitle("Snake Game");
        setSize(WIDTH, HEIGHT);
        setResizable(false);
        setDefaultCloseOperation(EXIT_ON_CLOSE);

        // 初始化蛇和食物
        snake = new Snake();
        food = new Food();

        // 设置定时器
        timer = new Timer(100, this);
        timer.start();

        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        // 移动蛇
        snake.move();

        // 如果蛇吃到了食物，重新生成食物
        if (snake.eat(food)) {
            food = new Food();
        }

        // 如果蛇撞到了墙壁或者自己的身体，游戏结束
        if (snake.hitWall() || snake.hitBody()) {
            timer.stop();
            JOptionPane.showMessageDialog(this, "Game Over");
            System.exit(0);
        }

        repaint();
    }

    public void paint(Graphics g) {
        // 绘制背景
        g.setColor(Color.WHITE);
        g.fillRect(0, 0, WIDTH, HEIGHT);

        // 绘制蛇和食物
        snake.draw(g);
        food.draw(g);
    }

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

class Snake {
    private final int SIZE = 10;
    private final int WIDTH = 300;
    private final int HEIGHT = 300;

    private int[] x = new int[WIDTH * HEIGHT / (SIZE * SIZE)];
    private int[] y = new int[WIDTH * HEIGHT / (SIZE * SIZE)];
    private int length = 3;
    private int direction = KeyEvent.VK_RIGHT;

    public Snake() {
        // 初始化蛇的位置
        x[0] = 50;
        y[0] = 50;
        x[1] = 40;
        y[1] = 50;
        x[2] = 30;
        y[2] = 50;
    }

    public void move() {
        // 移动蛇的身体
        for (int i = length - 1; i > 0; i--) {
            x[i] = x[i - 1];
            y[i] = y[i - 1];
        }

        // 移动蛇的头部
        switch (direction) {
            case KeyEvent.VK_UP:
                y[0] -= SIZE;
                break;
            case KeyEvent.VK_DOWN:
                y[0] += SIZE;
                break;
            case KeyEvent.VK_LEFT:
                x[0] -= SIZE;
                break;
            case KeyEvent.VK_RIGHT:
                x[0] += SIZE;
                break;
        }
    }

    public boolean eat(Food food) {
        // 如果蛇的头部和食物位置重合，说明蛇吃到了食物
        if (x[0] == food.getX() && y[0] == food.getY()) {
            length++;
            return true;
        } else {
            return false;
        }
    }

    public boolean hitWall() {
        // 如果蛇撞到了墙壁，返回true
        if (x[0] < 0 || x[0] >= WIDTH || y[0] < 0 || y[0] >= HEIGHT) {
            return true;
        } else {
            return false;
        }
    }

    public boolean hitBody() {
        // 如果蛇撞到了自己的身体，返回true
        for (int i = 1; i < length; i++) {
            if (x[0] == x[i] && y[0] == y[i]) {
                return true;
            }
        }

        return false;
    }

    public void draw(Graphics g) {
        // 绘制蛇的身体
        for (int i = 0; i < length; i++) {
            g.setColor(Color.BLACK);
            g.fillRect(x[i], y[i], SIZE, SIZE);
        }
    }

    public void setDirection(int direction) {
        this.direction = direction;
    }
}

class Food {
    private final int SIZE = 10;
    private final int WIDTH = 300;
    private final int HEIGHT = 300;

    private int x;
    private int y;

    public Food() {
        // 随机生成食物的位置
        x = (int) (Math.random() * (WIDTH - SIZE) / SIZE) * SIZE;
        y = (int) (Math.random() * (HEIGHT - SIZE) / SIZE) * SIZE;
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

    public void draw(Graphics g) {
        // 绘制食物
        g.setColor(Color.RED);
        g.fillRect(x, y, SIZE, SIZE);
    }
}

这个代码示例实现了一个简单的贪吃蛇小游戏，包含了蛇的移动、吃食物、撞墙或撞身体时游戏结束等功能。你可以在此基础上进行修改和扩展，实现更丰富的游戏玩法。