You need strong understanding, that's true and the exam has less API questions than conceptual ones that
test your understanding. Cound on questions regarding
SOAP and WSDL. You have to know the most important elements of them and understand how their work, probably identify standard-conforming and invalid fragments. You also need to understand basic concepts, like SOAP vs. REST, XML basics, XSD basics. Also there is a significant number of scenario-based questions. As for the API, some basics, like a very simple DOM example or some JAX-WS and JAXB annotations. Don't forget that exactly remembering and recognizing answers is different and the latter is much easier. For example, if you see a DOM code fragment with a class Element instead of Node, you can immediately exclude that answer. And lots of times, the questions are from such a type, if you have worked or studied the given topic, you will recognize the answer either directly or by exclusion. Also be prepared for some JAXR stuff, it's on the exam although nobody uses it. And you are on a good track with Ivan Krizsan's study notes, I also used that for preparation and I passed.
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