贪吃蛇java程序代码

以下是一个简单的贪吃蛇Java程序代码示例：

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 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 ROWS = 30;
    public static final int COLS = 30;
    public static final int BLOCK_SIZE = 20;

    private Thread thread;
    private boolean isRunning;

    private LinkedList<Point> snake;
    private Point food;
    private int direction;

    public SnakeGame() {
        setPreferredSize(new Dimension(COLS * BLOCK_SIZE, ROWS * BLOCK_SIZE));
        setBackground(Color.BLACK);
        setFocusable(true);
        addKeyListener(this);

        init();
    }

    private void init() {
        snake = new LinkedList<Point>();
        snake.add(new Point(COLS / 2, ROWS / 2));
        snake.add(new Point(COLS / 2, ROWS / 2 + 1));
        snake.add(new Point(COLS / 2, ROWS / 2 + 2));

        direction = KeyEvent.VK_UP;

        createFood();

        isRunning = true;
        thread = new Thread(this);
        thread.start();
    }

    private void createFood() {
        int x = (int) (Math.random() * COLS);
        int y = (int) (Math.random() * ROWS);
        food = new Point(x, y);
    }

    private void move() {
        Point head = snake.getFirst();
        int x = head.x;
        int y = head.y;

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

        if (x < 0 || x >= COLS || y < 0 || y >= ROWS) {
            gameOver();
            return;
        }

        Point newHead = new Point(x, y);

        if (snake.contains(newHead)) {
            gameOver();
            return;
        }

        snake.addFirst(newHead);

        if (newHead.equals(food)) {
            createFood();
        } else {
            snake.removeLast();
        }
    }

    private void gameOver() {
        isRunning = false;
        System.out.println("Game Over!");
    }

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

        g.setColor(Color.RED);
        g.fillRect(food.x * BLOCK_SIZE, food.y * BLOCK_SIZE, BLOCK_SIZE, BLOCK_SIZE);

        g.setColor(Color.WHITE);
        for (Point p : snake) {
            g.fillRect(p.x * BLOCK_SIZE, p.y * BLOCK_SIZE, BLOCK_SIZE, BLOCK_SIZE);
        }
    }

    @Override
    public void run() {
        while (isRunning) {
            move();
            repaint();

            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public void keyPressed(KeyEvent e) {
        int keyCode = e.getKeyCode();

        if (keyCode == KeyEvent.VK_LEFT && direction != KeyEvent.VK_RIGHT) {
            direction = keyCode;
        } else if (keyCode == KeyEvent.VK_RIGHT && direction != KeyEvent.VK_LEFT) {
            direction = keyCode;
        } else if (keyCode == KeyEvent.VK_UP && direction != KeyEvent.VK_DOWN) {
            direction = keyCode;
        } else if (keyCode == KeyEvent.VK_DOWN && direction != KeyEvent.VK_UP) {
            direction = keyCode;
        }
    }

    @Override
    public void keyReleased(KeyEvent e) {

    }

    @Override
    public void keyTyped(KeyEvent e) {

    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Snake Game");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(new SnakeGame());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
}

该程序使用Java Swing库创建了一个简单的贪吃蛇游戏。玩家可以使用上下左右箭头键控制蛇的移动方向，吃掉食物后蛇的长度会增加。如果蛇撞到边界或自己的身体，则游戏结束。