如何在不知道输入文件的类的情况下获取它(java)

如果用户从GUI选择文件，我不知道如何使用getDeclaredMethods()(反射).
像这样的东西:

Hi,

I can''t figure out, how to use getDeclaredMethods() (reflection) if the user chooses the file from GUI.
Something like this:

Class inclass= Class.forName("ClassName");
Method[] methods = inclass.getDeclaredMethods();

但我不知道"ClassName"，我稍后再知道.

我想从输入文件中获取声明的方法，然后在我的GUI中列出它们.用户可以选择一个txt或java文件，当他/她这样做时，程序将从中获取方法(如果有的话)并将它们列出在jList上.
如果我知道对象的名称，则可以使用，但是以后出现时，它不可用.

从下面的评论中复制的其他信息
所以我的程序将像这样工作:启动后，用户选择一个文件(txt或java)，当这种情况发生时，程序将文件的文本放入Arraylist中，并列出文件的方法和JList上的字段并显示它们.
但是inputfile.getClass()无效，因为它不是对象，如果我不知道类名，我也不知道如何获取输入文件的类在程序启动之前.

谢谢您的帮助.

But I don''t know "ClassName", I get it later.

I''d like to get the declared methods from the input file, and then list them in my GUI. The user can choose a txt or java file, when he/she did, the program will get the methods from this (if there are any) and list them on a jList.
Works if I know the Object''s name, but not if it comes later.

additional information copied from comment below
So my program would work like this: it starts, the user chooses a file (txt or java), when this happens the program gets the file''s text into an Arraylist, and list''s the file''s methods and fields on a JList and displays them.
But the inputfile.getClass() won''t work, since it''s not an object, and I don''t know how to get the input file''s class, if I don''t know the class name before the program starts.

Thank you for helping me.