Question overloading method

Question

Hi, thanks for reading this message.
Here is my problem.
The context is Servlet and Jsp.
I am developping and environnement for JSP developpers. This way I defined superclass for JSP pages that give people a basic behavior like getting access to the current user and some usefull methods to access session's parameters.
This way I developpe a first abstract class with the fallowing method :
protected void preProcessRequest(HttpServletRequest request, HttpServletResponse response) { ... }
Now I have to subclass this method in a concreate class. This one will load the current user but, during this operation, an exception can be raised. This is normal. So the signature is now :
protected void preProcessRequest(HttpServletRequest request, HttpServletResponse response) throws TinyException { ... } ;
I andrestand why it can't be compiled but don't know how to do this an other way.
Thank you

Answer 1

But it's a more general question. When you define a
framework, you don't know how it will be used. And
what append if you subclass a method of a framework
and your implementation throws an exception that
was not in the abstract classes. Then the framework was badly designed. It needs to be loose enough to allow all sorts of implementations but strict enough to be useful.
Have you ever wondered why the read & write of the abstract classes InputStream and InputStream throw IOException? Because otherwise it'd be impossible to declare to throw them in the subclasses, that's the way Java goes...
So blame those who made the abstract class - you cannot declare to throw a totally unexpected exception from the subclass.
But do note that while you cannot declare to throw the exception, nothing stops you from actually throwing it...