基于java的贪吃蛇小游戏

贪吃蛇游戏需要做两点：图形界面和游戏逻辑。在 Java 中，可以使用 Swing 或 JavaFX 来创建图形界面。下面代码创建了一个简单的 Swing 窗口，实现了一个基本的贪吃蛇游戏。在游戏中，使用方向键控制贪吃蛇的移动，吃到食物会增加蛇的长度，如果蛇撞到墙壁或者自己的身体，则游戏结束。

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

public class SnakeGame extends JFrame implements ActionListener, KeyListener {
    private ArrayList<Point> snake;
    private Point fruit;
    private Timer timer;
    private int direction;
    private boolean gameOver;

    public SnakeGame() {
        setTitle("贪吃蛇游戏");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(400, 400);
        setLocationRelativeTo(null);

        snake = new ArrayList<>();
        snake.add(new Point(10, 10));
        fruit = new Point(5, 5);

        direction = KeyEvent.VK_RIGHT;
        gameOver = false;

        timer = new Timer(100, this);
        timer.start();

        addKeyListener(this);
        setFocusable(true);
        setFocusTraversalKeysEnabled(false);

        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        if (!gameOver) {
            move();
            checkCollision();
            checkFruit();
            repaint();
        }
    }

    public void paint(Graphics g) {
        super.paint(g);
        if (!gameOver) {
            g.setColor(Color.RED);
            g.fillRect(fruit.x * 20, fruit.y * 20, 20, 20);

            g.setColor(Color.GREEN);
            for (Point point : snake) {
                g.fillRect(point.x * 20, point.y * 20, 20, 20);
            }
        } else {
            g.setColor(Color.BLACK);
            g.setFont(new Font("Arial", Font.BOLD, 30));
            g.drawString("游戏结束", 130, 200);
        }
    }

    public void move() {
        for (int i = snake.size() - 1; i > 0; i--) {
            snake.get(i).x = snake.get(i - 1).x;
            snake.get(i).y = snake.get(i - 1).y;
        }

        switch (direction) {
            case KeyEvent.VK_UP:
                snake.get(0).y--;
                break;
            case KeyEvent.VK_DOWN:
                snake.get(0).y++;
                break;
            case KeyEvent.VK_LEFT:
                snake.get(0).x--;
                break;
            case KeyEvent.VK_RIGHT:
                snake.get(0).x++;
                break;
        }
    }

    public void checkCollision() {
        Point head = snake.get(0);
        if (head.x < 0 || head.x >= 20 || head.y < 0 || head.y >= 20) {
            gameOver = true;
            timer.stop();
        }

        for (int i = 1; i < snake.size(); i++) {
            if (head.x == snake.get(i).x && head.y == snake.get(i).y) {
                gameOver = true;
                timer.stop();
                break;
            }
        }
    }

    public void checkFruit() {
        Point head = snake.get(0);
        if (head.x == fruit.x && head.y == fruit.y) {
            snake.add(new Point(snake.get(snake.size() - 1)));
            generateFruit();
        }
    }

    public void generateFruit() {
        Random random = new Random();
        boolean validFruit = false;

        while (!validFruit) {
            int x = random.nextInt(20);
            int y = random.nextInt(20);
            fruit = new Point(x, y);

            boolean collision = false;
            for (Point point : snake) {
                if (fruit.x == point.x && fruit.y == point.y) {
                    collision = true;
                    break;
                }
            }

            if (!collision) {
                validFruit = true;
            }
        }
    }

    public void keyPressed(KeyEvent e) {
        int key = e.getKeyCode();
        if ((key == KeyEvent.VK_LEFT || key == KeyEvent.VK_RIGHT || key == KeyEvent.VK_UP || key == KeyEvent.VK_DOWN) &&
                (key + direction) % 2 != 0) {
            direction = key;
        }
    }

    public void keyReleased(KeyEvent e) {
    }

    public void keyTyped(KeyEvent e) {
    }

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