用Java语言设计一个扫雷游戏，可以通过下拉菜单设置扫雷难度，记录扫雷过程花费的时间，增加开始按钮控制扫雷的开始。写出完整代码

好的，以下是一个简单的Java语言设计扫雷游戏的示例代码：

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;

public class MineSweeper implements ActionListener {

    private JFrame frame;
    private JPanel panel;
    private JLabel label;
    private JButton[][] buttons;
    private JMenuBar menuBar;
    private JMenu levelMenu;
    private JMenuItem beginnerItem, intermediateItem, advancedItem;
    private int rows = 9, cols = 9, mines = 10;
    private int[][] board;
    private boolean[][] revealed;
    private boolean[][] flagged;
    private int time = 0;
    private Timer timer;
    private JButton startButton;

    public MineSweeper() {
        // 初始化游戏界面
        frame = new JFrame("Mine Sweeper");
        panel = new JPanel(new GridLayout(rows, cols));
        label = new JLabel("Time: 0s");
        buttons = new JButton[rows][cols];
        board = new int[rows][cols];
        revealed = new boolean[rows][cols];
        flagged = new boolean[rows][cols];
        timer = new Timer(1000, this);
        startButton = new JButton("Start");
        startButton.addActionListener(this);

        // 初始化菜单栏
        menuBar = new JMenuBar();
        levelMenu = new JMenu("Level");
        beginnerItem = new JMenuItem("Beginner");
        intermediateItem = new JMenuItem("Intermediate");
        advancedItem = new JMenuItem("Advanced");
        beginnerItem.addActionListener(this);
        intermediateItem.addActionListener(this);
        advancedItem.addActionListener(this);
        levelMenu.add(beginnerItem);
        levelMenu.add(intermediateItem);
        levelMenu.add(advancedItem);
        menuBar.add(levelMenu);
        frame.setJMenuBar(menuBar);

        // 添加按钮到游戏界面
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                buttons[i][j] = new JButton();
                buttons[i][j].addActionListener(this);
                panel.add(buttons[i][j]);
            }
        }

        // 添加组件到游戏界面
        frame.add(panel, BorderLayout.CENTER);
        frame.add(label, BorderLayout.NORTH);
        frame.add(startButton, BorderLayout.SOUTH);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }

    // 开始游戏
    public void startGame() {
        // 初始化游戏面板
        panel.removeAll();
        revealed = new boolean[rows][cols];
        flagged = new boolean[rows][cols];
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                buttons[i][j] = new JButton();
                buttons[i][j].addActionListener(this);
                panel.add(buttons[i][j]);
            }
        }

        // 初始化游戏时间和地雷数量
        time = 0;
        label.setText("Time: " + time + "s");
        mines = rows * cols / 10;

        // 初始化游戏板块
        Random rand = new Random();
        for (int i = 0; i < mines; i++) {
            int x = rand.nextInt(rows);
            int y = rand.nextInt(cols);
            if (board[x][y] == -1) {
                i--;
            } else {
                board[x][y] = -1;
                for (int dx = -1; dx <= 1; dx++) {
                    for (int dy = -1; dy <= 1; dy++) {
                        if (x + dx >= 0 && x + dx < rows && y + dy >= 0 && y + dy < cols && board[x + dx][y + dy] != -1) {
                            board[x + dx][y + dy]++;
                        }
                    }
                }
            }
        }

        // 开始计时
        timer.start();
    }

    // 点击按钮事件
    public void actionPerformed(ActionEvent e) {
        // 选择难度
        if (e.getSource() == beginnerItem) {
            rows = 9;
            cols = 9;
            startGame();
        } else if (e.getSource() == intermediateItem) {
            rows = 16;
            cols = 16;
            startGame();
        } else if (e.getSource() == advancedItem) {
            rows = 16;
            cols = 30;
            startGame();
        }
        // 开始游戏
        else if (e.getSource() == startButton) {
            startGame();
        }
        // 点击按钮
        else {
            for (int i = 0; i < rows; i++) {
                for (int j = 0; j < cols; j++) {
                    if (e.getSource() == buttons[i][j]) {
                        // 点击未翻开的格子
                        if (!revealed[i][j] && !flagged[i][j]) {
                            revealed[i][j] = true;
                            buttons[i][j].setEnabled(false);
                            // 点中地雷，游戏结束
                            if (board[i][j] == -1) {
                                timer.stop();
                                JOptionPane.showMessageDialog(frame, "Game Over!");
                                for (int x = 0; x < rows; x++) {
                                    for (int y = 0; y < cols; y++) {
                                        if (board[x][y] == -1) {
                                            buttons[x][y].setText("X");
                                        }
                                    }
                                }
                            }
                            // 点中数字，显示数字
                            else if (board[i][j] > 0) {
                                buttons[i][j].setText(String.valueOf(board[i][j]));
                            }
                            // 点中空白，递归翻开周围的空白格子
                            else {
                                buttons[i][j].setText("");
                                for (int dx = -1; dx <= 1; dx++) {
                                    for (int dy = -1; dy <= 1; dy++) {
                                        if (i + dx >= 0 && i + dx < rows && j + dy >= 0 && j + dy < cols) {
                                            actionPerformed(new ActionEvent(buttons[i + dx][j + dy], 0, ""));
                                        }
                                    }
                                }
                            }
                        }
                        // 右键点击标记或取消标记
                        else if (!revealed[i][j] && SwingUtilities.isRightMouseButton(e)) {
                            flagged[i][j] = !flagged[i][j];
                            if (flagged[i][j]) {
                                buttons[i][j].setText("F");
                            } else {
                                buttons[i][j].setText("");
                            }
                        }
                    }
                }
            }
        }
        // 更新游戏时间
        if (timer.isRunning()) {
            time++;
            label.setText("Time: " + time + "s");
        }
    }

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

以上代码是一个简单的扫雷游戏实现，您可以根据自己的需求进行修改和优化。