This week's book giveaway is in the Other Open Source APIs forum. We're giving away four copies of Storm Applied and have Sean Allen, Peter Pathirana & Matthew Jankowski on-line! See this thread for details.
Thus, every service has its own domain objects. These objects are simple java beans (get/set) which describe the input fields to execute the service. We need this layer of independence because the service can also be called from inside.
So, the classes that jaxb generates to convert the XML to java need to be converter again to the domain objects. So the converter does basicly this: