写一个贪吃蛇的java代码

好的，以下是一个简单的贪吃蛇Java代码示例：

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

public class Snake extends JFrame implements ActionListener {
    private Timer timer;
    private SnakePanel panel;
    private JButton startButton;
    private JButton pauseButton;
    private JButton resumeButton;

    public Snake() {
        super("Snake");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setResizable(false);

        panel = new SnakePanel();
        getContentPane().add(panel, BorderLayout.CENTER);

        JPanel buttonPanel = new JPanel(new FlowLayout());
        startButton = new JButton("Start");
        startButton.addActionListener(this);
        buttonPanel.add(startButton);

        pauseButton = new JButton("Pause");
        pauseButton.addActionListener(this);
        buttonPanel.add(pauseButton);
        pauseButton.setEnabled(false);

        resumeButton = new JButton("Resume");
        resumeButton.addActionListener(this);
        buttonPanel.add(resumeButton);
        resumeButton.setEnabled(false);

        getContentPane().add(buttonPanel, BorderLayout.SOUTH);

        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == startButton) {
            panel.start();
            startButton.setEnabled(false);
            pauseButton.setEnabled(true);
        } else if (e.getSource() == pauseButton) {
            panel.pause();
            pauseButton.setEnabled(false);
            resumeButton.setEnabled(true);
        } else if (e.getSource() == resumeButton) {
            panel.resume();
            resumeButton.setEnabled(false);
            pauseButton.setEnabled(true);
        }
    }

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

class SnakePanel extends JPanel implements ActionListener {
    private static final int ROWS = 20;
    private static final int COLS = 20;
    private static final int CELL_SIZE = 20;
    private int[][] grid;
    private int snakeLength;
    private int[] snakeRow;
    private int[] snakeCol;
    private int foodRow;
    private int foodCol;
    private boolean gameover;
    private Timer timer;

    public SnakePanel() {
        setPreferredSize(new Dimension(COLS * CELL_SIZE, ROWS * CELL_SIZE));
        setBackground(Color.WHITE);
        setFocusable(true);
        requestFocus();

        addKeyListener(new KeyAdapter() {
            public void keyPressed(KeyEvent e) {
                int code = e.getKeyCode();
                if (code == KeyEvent.VK_LEFT && grid[snakeRow[0]][snakeCol[0] - 1] != 1) {
                    move(-1, 0);
                } else if (code == KeyEvent.VK_RIGHT && grid[snakeRow[0]][snakeCol[0] + 1] != 1) {
                    move(1, 0);
                } else if (code == KeyEvent.VK_UP && grid[snakeRow[0] - 1][snakeCol[0]] != 1) {
                    move(0, -1);
                } else if (code == KeyEvent.VK_DOWN && grid[snakeRow[0] + 1][snakeCol[0]] != 1) {
                    move(0, 1);
                }
            }
        });

        grid = new int[ROWS][COLS];
        snakeLength = 3;
        snakeRow = new int[ROWS * COLS];
        snakeCol = new int[ROWS * COLS];
        for (int i = 0; i < snakeLength; i++) {
            snakeRow[i] = ROWS / 2;
            snakeCol[i] = COLS / 2 - i;
            grid[snakeRow[i]][snakeCol[i]] = 1;
        }
        placeFood();

        timer = new Timer(100, this);
    }

    public void start() {
        timer.start();
    }

    public void pause() {
        timer.stop();
    }

    public void resume() {
        timer.start();
    }

    public void actionPerformed(ActionEvent e) {
        move(0, 1);
    }

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

        for (int row = 0; row < ROWS; row++) {
            for (int col = 0; col < COLS; col++) {
                if (grid[row][col] == 1) {
                    g.setColor(Color.BLACK);
                    g.fillRect(col * CELL_SIZE, row * CELL_SIZE, CELL_SIZE, CELL_SIZE);
                } else if (grid[row][col] == 2) {
                    g.setColor(Color.RED);
                    g.fillOval(col * CELL_SIZE, row * CELL_SIZE, CELL_SIZE, CELL_SIZE);
                }
            }
        }

        if (gameover) {
            g.setColor(Color.BLUE);
            g.setFont(new Font("Arial", Font.BOLD, 40));
            g.drawString("Game Over", COLS * CELL_SIZE / 2 - 100, ROWS * CELL_SIZE / 2);
        }
    }

    private void move(int dx, int dy) {
        if (gameover) {
            return;
        }

        int newHeadRow = snakeRow[0] + dy;
        int newHeadCol = snakeCol[0] + dx;

        if (newHeadRow < 0 || newHeadRow >= ROWS || newHeadCol < 0 || newHeadCol >= COLS) {
            gameover = true;
            repaint();
            return;
        }

        if (grid[newHeadRow][newHeadCol] == 1) {
            gameover = true;
            repaint();
            return;
        }

        if (grid[newHeadRow][newHeadCol] == 2) {
            snakeLength++;
            snakeRow[snakeLength - 1] = snakeRow[snakeLength - 2];
            snakeCol[snakeLength - 1] = snakeCol[snakeLength - 2];
            grid[newHeadRow][newHeadCol] = 1;
            placeFood();
        } else {
            for (int i = snakeLength - 1; i > 0; i--) {
                snakeRow[i] = snakeRow[i - 1];
                snakeCol[i] = snakeCol[i - 1];
            }
        }

        snakeRow[0] = newHeadRow;
        snakeCol[0] = newHeadCol;
        grid[newHeadRow][newHeadCol] = 1;

        repaint();
    }

    private void placeFood() {
        int row, col;
        do {
            row = (int) (Math.random() * ROWS);
            col = (int) (Math.random() * COLS);
        } while (grid[row][col] != 0);
        foodRow = row;
        foodCol = col;
        grid[foodRow][foodCol] = 2;
    }
}

这个代码使用Java Swing实现了一个简单的贪吃蛇游戏，并且具有基本的游戏控制（开始、暂停、恢复）。