Hi Lalit !!!
I'm preparing for the exam. I don't think we need to know thoses classes.
In HFSJ(page 303), you'll read this:
The Container generates a class from your JSP that implements the HttpJspPage interface. This is the only part of the generated servlet's API that you need to know.
....
All you need to know about are key methods:
jspinit()jspDestroy()_jspService()
Good luck.