关闭应用程序类中的DBHelper

public class MyApp {
    private DBHelper dbHelper;
    
    public MyApp() {
        dbHelper = new DBHelper();
    }
    
    public void doSomething() {
        // 执行一些操作
    }
    
    public void close() {
        dbHelper.closeConnection();
    }
}

public class DBHelper {
    private Connection connection;
    
    public DBHelper() {
        // 创建数据库连接
        connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "username", "password");
    }
    
    public void closeConnection() {
        try {
            if (connection != null && !connection.isClosed()) {
                connection.close();
            }
        } catch (SQLException e) {
            // 处理异常
        }
    }
}