如何实现贪吃蛇用空格控制开始和暂停，给我JAVA示例代码

好的，我会为您展示一个简单的贪吃蛇游戏，实现了用空格控制开始和暂停的功能，在Java中的示例代码如下：

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;

public class SnakeGame extends JPanel implements ActionListener, KeyListener {
    private static final long serialVersionUID = 1L;
    private final int WIDTH = 300;
    private final int HEIGHT = 300;
    private final int CELL_SIZE = 10;
    private final int TOTAL_CELLS = (WIDTH * HEIGHT) / (CELL_SIZE * CELL_SIZE);
    private boolean gameRunning = false;
    private boolean gamePaused = false;
    private Timer timer;
    private int[] x = new int[TOTAL_CELLS];
    private int[] y = new int[TOTAL_CELLS];
    private int bodyParts = 6;
    private int appleX;
    private int appleY;
    private char direction = 'R';

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

    public void initGame() {
        gameRunning = true;
        gamePaused = false;
        direction = 'R';
        timer = new Timer(50, this);
        timer.start();
        generateApple();
    }

    public void generateApple() {
        int r = (int) (Math.random() * (WIDTH - CELL_SIZE));
        appleX = r % CELL_SIZE == 0 ? r : (r / CELL_SIZE) * CELL_SIZE;
        r = (int) (Math.random() * (HEIGHT - CELL_SIZE));
        appleY = r % CELL_SIZE == 0 ? r : (r / CELL_SIZE) * CELL_SIZE;
    }

    public void checkCollision() {
        for (int i = bodyParts; i > 0; i--) {
            if ((x[0] == x[i] && y[0] == y[i]) || x[0] < 0 || x[0] > WIDTH - CELL_SIZE || y[0] < 0 || y[0] > HEIGHT - CELL_SIZE) {
                gameRunning = false;
            }
        }
        if (x[0] == appleX && y[0] == appleY) {
            bodyParts++;
            generateApple();
        }
    }

    public void move() {
        for (int i = bodyParts; i > 0; i--) {
            x[i] = x[i - 1];
            y[i] = y[i - 1];
        }
        switch (direction) {
            case 'U':
                y[0] -= CELL_SIZE;
                break;
            case 'D':
                y[0] += CELL_SIZE;
                break;
            case 'L':
                x[0] -= CELL_SIZE;
            case 'R':
                x[0] += CELL_SIZE;
                break;
        }
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        drawSnake(g);
        drawApple(g);
    }

    public void drawSnake(Graphics g) {
        g.setColor(Color.GREEN);
        for (int i = 0; i < bodyParts; i++) {
            g.fillRect(x[i], y[i], CELL_SIZE, CELL_SIZE);
        }
    }

    public void drawApple(Graphics g) {
        g.setColor(Color.RED);
        g.fillRect(appleX, appleY, CELL_SIZE, CELL_SIZE);
    }

    public void actionPerformed(ActionEvent e) {
        if (gameRunning && !gamePaused) {
            checkCollision();
            move();
        }
        repaint();
    }

    public void keyPressed(KeyEvent e) {
        if (!gameRunning) {
            initGame();
        }
        if (e.getKeyCode() == KeyEvent.VK_SPACE) {
            gamePaused = !gamePaused;
        } else if ((e.getKeyCode() == KeyEvent.VK_UP || e.getKeyCode() == KeyEvent.VK_W) && direction != 'D') {
            direction = 'U';
        } else if ((e.getKeyCode() == KeyEvent.VK_DOWN || e.getKeyCode() == KeyEvent.VK_S) && direction != 'U') {
            direction = 'D';
        } else if ((e.getKeyCode() == KeyEvent.VK_LEFT || e.getKeyCode() == KeyEvent.VK_A) && direction != 'R') {
            direction = 'L';
        } else if ((e.getKeyCode() == KeyEvent.VK_RIGHT || e.getKeyCode() == KeyEvent.VK_D) && direction != 'L') {
            direction = 'R';
        }
    }

    public void keyReleased(KeyEvent e) {}

    public void keyTyped(KeyEvent e) {}

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

这个示例中，空格键可以用来控制游戏的开始和暂停，其他方向键用来控制蛇的运动方向。当蛇吃到苹果时，会增长一个身体部位，每吃到一个苹果都会重新生成一个新的苹果。游戏会在蛇头触碰到游戏边界或者蛇身时结束。