写一段贪吃蛇代码

好的，以下是一个简单的贪吃蛇游戏的Java代码示例：

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

public class SnakeGame extends JFrame implements ActionListener {
    private Random rand = new Random();
    private Timer timer;
    private int delay = 100;
    private int dotSize = 10;
    private int boardWidth = 300;
    private int boardHeight = 300;
    private int dots = 3;
    private int[] x = new int[500];
    private int[] y = new int[500];
    private int appleX;
    private int appleY;
    private boolean leftDirection = false;
    private boolean rightDirection = true;
    private boolean upDirection = false;
    private boolean downDirection = false;
    private boolean inGame = true;

    public SnakeGame() {
        setTitle("Snake Game");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(boardWidth, boardHeight);
        setResizable(false);
        setLocationRelativeTo(null);
        initGame();
    }

    public void initGame() {
        for (int i = 0; i < dots; i++) {
            x[i] = 50 - i * dotSize;
            y[i] = 50;
        }
        locateApple();
        timer = new Timer(delay, this);
        timer.start();
    }

    public void paint(Graphics g) {
        super.paint(g);
        if (inGame) {
            g.setColor(Color.RED);
            g.fillOval(appleX, appleY, dotSize, dotSize);
            for (int i = 0; i < dots; i++) {
                g.setColor(Color.GREEN);
                g.fillOval(x[i], y[i], dotSize, dotSize);
            }
            Toolkit.getDefaultToolkit().sync();
        } else {
            gameOver(g);
        }
    }

    public void gameOver(Graphics g) {
        String message = "Game Over";
        Font font = new Font("Helvetica", Font.BOLD, 14);
        FontMetrics metrics = getFontMetrics(font);
        g.setColor(Color.BLACK);
        g.setFont(font);
        g.drawString(message, (boardWidth - metrics.stringWidth(message)) / 2, boardHeight / 2);
    }

    public void checkApple() {
        if ((x[0] == appleX) && (y[0] == appleY)) {
            dots++;
            locateApple();
        }
    }

    public void move() {
        for (int i = dots; i > 0; i--) {
            x[i] = x[(i - 1)];
            y[i] = y[(i - 1)];
        }
        if (leftDirection) {
            x[0] -= dotSize;
        }
        if (rightDirection) {
            x[0] += dotSize;
        }
        if (upDirection) {
            y[0] -= dotSize;
        }
        if (downDirection) {
            y[0] += dotSize;
        }
    }

    public void checkCollision() {
        for (int i = dots; i > 0; i--) {
            if ((i > 4) && (x[0] == x[i]) && (y[0] == y[i])) {
                inGame = false;
            }
        }
        if (y[0] >= boardHeight) {
            inGame = false;
        }
        if (y[0] < 0) {
            inGame = false;
        }
        if (x[0] >= boardWidth) {
            inGame = false;
        }
        if (x[0] < 0) {
            inGame = false;
        }
        if (!inGame) {
            timer.stop();
        }
    }

    public void locateApple() {
        int r = rand.nextInt((int) (boardWidth / dotSize)) * dotSize;
        appleX = r;
        r = rand.nextInt((int) (boardHeight / dotSize)) * dotSize;
        appleY = r;
    }

    public void actionPerformed(ActionEvent e) {
        if (inGame) {
            checkApple();
            checkCollision();
            move();
        }
        repaint();
    }

    public static void main(String[] args) {
        SnakeGame game = new SnakeGame();
        game.setVisible(true);
    }
}

这段代码是一个简单的贪吃蛇游戏，使用Java语言编写，采用了Java Swing框架实现图形界面。在代码中，使用了Timer类实现定时器，用于控制贪吃蛇的移动和游戏进程。同时，还实现了贪吃蛇的移动、碰撞检测、苹果的生成等功能。