I was wondering if anyone knows the depth of knowledge the exam requires for patterns. For examples, each pattern has several strategies, and each of these strategies have certain advantages/disadvantages. Are we required to know these?
You do not need implementation strategy level knowledge of the patterns. The test gives you a general description of a design goal, and its pretty clear what the right answer is, even if you have just read about patterns without ever implementing any of them.
You need to know the patterns associated with Servlet and JSP and applications using them. Regard the Design pattern as important, as it is a place where you can lose marks . The questions in this area can be tricky.(they look very easy though)
Patterns specified in HFS should be near to enough.