java - 使用executeQuery时出现NullPointerException

Question

我有一个空指针异常

ResultSet rs = aStatement.executeQuery(Query); // it can't be executed 

我的代码是这样的:

 public static boolean testLogin(String user, String password) throws SQLException {
    String Query = "select * from TBL_Users where userName = '" + user + "' and  passWord = '" + password + "' ";
    ResultSet rs = aStatement.executeQuery(Query);

    while (rs.next()) {

        info.Id = rs.getInt("ID");
        info.userName = rs.getString("userName");
        info.Name = rs.getString("User_Name");
        info.Password = rs.getString("passWord");
        info.isAdmin = rs.getBoolean("Admin");
        return true;
    }
    return false;
}

}

Answer 1

很可能aStatement为空。