JAX-RPC is a bit crazy these days. The reference implementation alters your deployment descriptors to account for some filters and so forth that are injected into your web application. The documentation for the web services developer kit explains the necessary commands that must be run in order to do this. I'm not sure, but I get the impression that other implementations can do whatever the heck they way in order to implement the web services you develop. That means, they may alter your deployment descriptors in a different way than the WSDK. Hope this helps you get started.
And... about its usage, do you think it is something important to learn for SCWCD 1.4 exam, and for software development?
Joined: May 29, 2003
I haven't totally read up on the requirements for SCWCD 1.4, but I'm pretty darn sure that it doesn't include JAX-RPC web services! As for whether it would be good for you to know -- definitely if you are using it. It is pretty interesting. I would think it has to do mostly with where your career is leading you. Web services are definitely becoming more a part of our wonderful lives ... if you're lucky enough to have a job to go to, that is.