I prepared it for 2 weeks... 3~4 hours per day during weekdays and all day during the weekends. Got an 88% for the test!
It was frustrating when I got an score of 52% for the mock exam in the HFSJ book. But I was tired and sleepy when I took the mock exam... Anyway, I'm very glad that I got a good score for the real exam.
I read the HFSJ book twice, took some of the free mock exams from
http://faq.javaranch.com/java/ScwcdLinks. Read the "PeabodyOnScwcdPatterns" and "Sample web.xml and TLD". They are all very helpful.
Thanks, JavaRanch!