Hello,
I cleared SCDJWS 5 yesterday with 77%. Number of question is 65, passing score 42%. I started to study last december (and cleared the SCJD in parallel).
Here is my advice when you want to start from scratch.
Begin with the following 6 months free online course :
http://www.javapassion.com/webservices/. I did only the 3 first months but once I did it, I feel comfortable with XML, XSLT, SAX, StaX, DOM, WSDL, SOAP. It explains exactly how to install software, how to develop, explains the notions with PowerPoint, and you have a mandatory homework to do every week. Very efficient.
Once you did this, read the outstanding Ivan Krisnan's guide, you can easily pick it up from this website. Skip the too much verbose parts, for example you don't have to know all the jaxws annotations neither the wsdl component model (a long part of the book, but there were no question about it). But you can print the book (sorry for the Amazonian Forest:-(, which is a excellent reference book for later. And top of the pop : CODE and COMPILE and TEST all the programms of the book, they are definitely NOT optional for the exam. that's true that they are not so many code snippets in the exam, but Ivan's ones are very useful for that, and you can grab good notions from them.
When somethin is not clear in Ivan's book you can refer to the Mikalai Zaikin's guide (thank you man). Easy to find in this website also.
You think you're ready? Now I will give you the good mock exams I found, well,
* let's start with the not-so-good whizlab, you can buy it but it refer to the old version of the exam and you will have to check every answer (some could be wrong).
* Second, go to Java Black Belt, and go to the web service beta questions (they are free), and check user's comment and check the answers too, precisely because it's beta questions. There was 2 or 3 question very similar in the exam.
* Top of the pop, the WGS-PREX-J230C from sun (google it). These are two mock exams (60 questions each), and some of the questions were the same (well, really really close) as the ones of the exam!!? So study them carefully, it's the very best mock exam of the certification. That's why I score so high because I didn't felt so confident just before the exam.
And most of the time, Sun offers freely a second chance to get the certification if you fail the first attempt, which makes another mock:
)
Last words : Unfortunately this forum is not as useful as the scjd's coderanch forum. The explanation is that there is not so much people that try the scdjws, and, anyway, this exam is not about subtelties and trap of web services, it's more a theorical exam, but the wide spectrum could make it a difficult exam... but the very low passing score makes it a "doable" exam. Finally I'm glad because I learned a lot and I will feel more cumfortable in my next job, ( a job a bout web services/ ESB...).
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David.