I've being using
JSP and
servlet technology for about 18 months now and last week I cleared the exam with 88%.
If you are familiar with the JSP technology and it's not completely new to you I would suggest you could clear the exam by ONLY studying Ken's notes. Couple this with regular attempts at the free mock exams and I can't see how you'll fail. If you want a good score (personally I don't think it matters to employers what % you get) then, like me, you can also study Miftah Khan's Servlet and JSP documents, although they do go into too much detail at times.
Apart from the design
pattern questions, I would say that every single question could be answered from the knowledge contained within Ken's notes (Cheers Ken!
).
Unless everything is new to you, you can forget about having to study the specs or even buying expensive text books.
If you don't use JSP and servlets on a regular basis, then I'm afraid it's monotonous studying and memorising of specs and texts books for you.