In order to build interoperable web services you need to restrict yourself to data types that can be modelled by schemas and WSDL, modulo the restrictions placed upon it by the
Web Services Basic Profile.
Take a look at the WSDL exposed by that service to see if there's anything in it that doesn't look like a datatype that Java can handle. Or you could just run a tool like wsdl2java over it, create a Java client from that, run it, and see what happens :-)