贪吃蛇Java运行源代码

以下是一个使用 Java Swing 编写的贪吃蛇小游戏的源代码示例：

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Point;
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 GamePanel extends JPanel implements ActionListener, KeyListener {

    private static final long serialVersionUID = 1L;

    public static final int WIDTH = 600;
    public static final int HEIGHT = 600;
    public static final int UNIT_SIZE = 20;
    public static final int GAME_UNITS = (WIDTH * HEIGHT) / (UNIT_SIZE * UNIT_SIZE);
    public static final int DELAY = 75;
    public static final int[] X_OFFSET = { 0, 0, -1, 1 };
    public static final int[] Y_OFFSET = { -1, 1, 0, 0 };

    private ArrayList<Point> snake;
    private Point food;
    private int score;
    private boolean running;
    private int direction;
    private Timer timer;
    private Random random;

    public GamePanel() {
        setPreferredSize(new Dimension(WIDTH, HEIGHT));
        setBackground(Color.black);
        setFocusable(true);
        addKeyListener(this);
        initGame();
    }

    private void initGame() {
        snake = new ArrayList<Point>();
        addSnakeUnit(new Point(WIDTH / 2, HEIGHT / 2));
        addSnakeUnit(new Point(WIDTH / 2, HEIGHT / 2 + UNIT_SIZE));
        addSnakeUnit(new Point(WIDTH / 2, HEIGHT / 2 + 2 * UNIT_SIZE));
        food = generateRandomFood();
        score = 0;
        running = true;
        direction = 0;
        timer = new Timer(DELAY, this);
        timer.start();
        random = new Random();
    }

    private Point generateRandomFood() {
        int x = random.nextInt(WIDTH / UNIT_SIZE) * UNIT_SIZE;
        int y = random.nextInt(HEIGHT / UNIT_SIZE) * UNIT_SIZE;
        return new Point(x, y);
    }

    private void addSnakeUnit(Point p) {
        snake.add(p);
    }

    private void removeSnakeUnit(Point p) {
        snake.remove(p);
    }

    private void moveSnake() {
        Point head = snake.get(0);
        int newX = head.x + X_OFFSET[direction] * UNIT_SIZE;
        int newY = head.y + Y_OFFSET[direction] * UNIT_SIZE;
        Point newHead = new Point(newX, newY);
        if (checkCollision(newHead)) {
            endGame();
        } else {
            addSnakeUnit(newHead);
            if (newHead.equals(food)) {
                score++;
                food = generateRandomFood();
            } else {
                removeSnakeUnit(snake.get(snake.size() - 1));
            }
        }
    }

    private boolean checkCollision(Point p) {
        return p.x < 0 || p.x >= WIDTH || p.y < 0 || p.y >= HEIGHT || snake.contains(p);
    }

    private void endGame() {
        running = false;
        timer.stop();
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (running) {
            moveSnake();
        }
        repaint();
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        drawSnake(g);
        drawFood(g);
        drawScore(g);
    }

    private void drawSnake(Graphics g) {
        for (int i = 0; i < snake.size(); i++) {
            Point p = snake.get(i);
            g.setColor(Color.white);
            g.fillRect(p.x, p.y, UNIT_SIZE, UNIT_SIZE);
        }
    }

    private void drawFood(Graphics g) {
        g.setColor(Color.red);
        g.fillRect(food.x, food.y, UNIT_SIZE, UNIT_SIZE);
    }

    private void drawScore(Graphics g) {
        g.setColor(Color.white);
        g.setFont(new Font("Arial", Font.BOLD, 20));
        g.drawString("Score: " + score, 20, 30);
    }

    @Override
    public void keyPressed(KeyEvent e) {
        int key = e.getKeyCode();
        if (key == KeyEvent.VK_LEFT && direction != 1) {
            direction = 0;
        } else if (key == KeyEvent.VK_RIGHT && direction != 0) {
            direction = 1;
        } else if (key == KeyEvent.VK_UP && direction != 3) {
            direction = 2;
        } else if (key == KeyEvent.VK_DOWN && direction != 2) {
            direction = 3;
        }
    }

    @Override
    public void keyTyped(KeyEvent e) {
    }

    @Override
    public void keyReleased(KeyEvent e) {
    }

}

这个程序定义了一个 GamePanel 类，它继承自 JPanel，并实现了 ActionListener 和 KeyListener 接口。在 GamePanel 中，我们定义了一些常量，例如窗口的宽度和高度、方格的大小、刷新时间间隔等等。我们还定义了一些变量，例如蛇的坐标、食物的坐标、玩家的得分等等。

在 initGame 方法中，我们初始化了游戏的状态，包括蛇的初始位置、食物的随机位置、得分、运行状态等等。在 moveSnake 方法中，我们实现了蛇的移动逻辑，包括头部的移动、身体的增加与删除、碰撞检测等等。在 endGame 方法中，我们结束了游戏。

在 actionPerformed 方法中，我们在游戏运行时不断刷新界面，在 paintComponent 方法中，我们绘制了蛇、食物、得分等界面元素。在 keyPressed 方法中，我们处理了键盘事件，根据按下的方向键来改变蛇的运动方向。

如果想要运行这个程序，需要将 GamePanel.java 和 SnakeGame.java 两个文件保存到同一个文件夹中，并使用 JDK 编译器将它们编译成 class 文件。然后，在命令行中进入这个文件夹，并执行以下命令：

java SnakeGame

这样，就可以启动贪吃蛇小游戏了。