Java实现一个贪吃蛇小游戏代码并加注释

好的，下面是Java实现贪吃蛇小游戏的代码，并附有详细注释：

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.LinkedList;
import java.util.Random;

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

// 游戏主体类
public class SnakeGame extends JPanel implements KeyListener {
    private static final long serialVersionUID = 1L;

    // 游戏区域的大小
    private static final int WIDTH = 800;
    private static final int HEIGHT = 800;

    // 蛇的移动速度
    private static final int SPEED = 100;

    // 蛇身的长度
    private static final int LENGTH = 20;

    // 蛇头的初始位置
    private static final int HEAD_X = WIDTH / 2;
    private static final int HEAD_Y = HEIGHT / 2;

    // 食物的初始位置
    private static final int FOOD_X = 100;
    private static final int FOOD_Y = 100;

    // 蛇的移动方向
    private static final int DIR_UP = 1;
    private static final int DIR_DOWN = -1;
    private static final int DIR_LEFT = 2;
    private static final int DIR_RIGHT = -2;

    // 随机数生成器
    private Random random = new Random();

    // 记录蛇的身体
    private LinkedList<Point> snake = new LinkedList<Point>();

    // 记录蛇的移动方向
    private int direction = DIR_UP;

    // 记录游戏是否结束
    private boolean isGameOver = false;

    // 记录当前得分
    private int score = 0;

    // 构造方法
    public SnakeGame() {
        // 设置游戏区域的大小
        setPreferredSize(new java.awt.Dimension(WIDTH, HEIGHT));

        // 添加键盘事件监听器
        addKeyListener(this);

        // 初始化蛇的身体
        snake.add(new Point(HEAD_X, HEAD_Y));
        snake.add(new Point(HEAD_X, HEAD_Y + LENGTH));
        snake.add(new Point(HEAD_X, HEAD_Y + LENGTH * 2));

        // 开始游戏循环
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (!isGameOver) {
                    try {
                        // 暂停一定时间，控制蛇的移动速度
                        Thread.sleep(SPEED);

                        // 移动蛇的身体
                        move();

                        // 重绘游戏区域
                        repaint();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    }

    // 绘制游戏区域
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);

        // 绘制蛇的身体
        for (Point p : snake) {
            g.setColor(Color.GREEN);
            g.fillRect(p.x, p.y, LENGTH, LENGTH);
        }

        // 绘制食物
        g.setColor(Color.RED);
        g.fillRect(FOOD_X, FOOD_Y, LENGTH, LENGTH);

        // 绘制得分
        g.setColor(Color.BLACK);
        g.drawString("Score: " + score, 10, 20);

        // 绘制游戏结束的提示信息
        if (isGameOver) {
            g.setColor(Color.BLACK);
            g.drawString("Game Over", WIDTH / 2 - 30, HEIGHT / 2);
        }
    }

    // 移动蛇的身体
    private void move() {
        // 计算蛇头的新位置
        Point head = snake.getFirst();
        Point newHead = new Point(head);
        switch (direction) {
            case DIR_UP:
                newHead.y -= LENGTH;
                break;
            case DIR_DOWN:
                newHead.y += LENGTH;
                break;
            case DIR_LEFT:
                newHead.x -= LENGTH;
                break;
            case DIR_RIGHT:
                newHead.x += LENGTH;
                break;
        }

        // 判断蛇头是否撞到墙壁
        if (newHead.x < 0 || newHead.x >= WIDTH || newHead.y < 0 || newHead.y >= HEIGHT) {
            isGameOver = true;
            return;
        }

        // 判断蛇头是否撞到自己的身体
        for (Point p : snake) {
            if (p.equals(newHead)) {
                isGameOver = true;
                return;
            }
        }

        // 判断蛇头是否吃到了食物
        if (newHead.x == FOOD_X && newHead.y == FOOD_Y) {
            score += 10;
            genFood();
        } else {
            snake.removeLast();
        }

        // 将新的蛇头加入到蛇的身体中
        snake.addFirst(newHead);
    }

    // 生成食物的位置
    private void genFood() {
        int x = random.nextInt(WIDTH / LENGTH) * LENGTH;
        int y = random.nextInt(HEIGHT / LENGTH) * LENGTH;
        FOOD_X = x;
        FOOD_Y = y;
    }

    // 处理键盘事件，改变蛇的移动方向
    public void keyPressed(KeyEvent e) {
        switch (e.getKeyCode()) {
            case KeyEvent.VK_UP:
                if (direction != DIR_DOWN) {
                    direction = DIR_UP;
                }
                break;
            case KeyEvent.VK_DOWN:
                if (direction != DIR_UP) {
                    direction = DIR_DOWN;
                }
                break;
            case KeyEvent.VK_LEFT:
                if (direction != DIR_RIGHT) {
                    direction = DIR_LEFT;
                }
                break;
            case KeyEvent.VK_RIGHT:
                if (direction != DIR_LEFT) {
                    direction = DIR_RIGHT;
                }
                break;
        }
    }

    // 必须实现的方法，用于处理键盘事件
    public void keyReleased(KeyEvent e) {
    }

    // 必须实现的方法，用于处理键盘事件
    public void keyTyped(KeyEvent e) {
    }

    // 游戏的入口方法
    public static void main(String[] args) {
        JFrame frame = new JFrame("贪吃蛇小游戏");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(new SnakeGame());
        frame.pack();
        frame.setVisible(true);
    }
}

以上就是Java实现贪吃蛇小游戏的代码及注释，希望能对你有所帮助！