Your best bet is to use the "New - Web services - WSDL" wizard and the
resulting WSDL editor to craft a WSDL document with doc/literal operations
that use the global elements from your Schema, then feed your WSDL document
to the "New - Web services - Web service" wizard to create a Java skeleton
top-down. There is a WSDL editor tutorial  and a top-down Web services
tutorial  that might help you get started.