OK, so the client does not
run (or host) a web service, it
accesses a web service that's running elsewhere. There's a wide range of possibilities for implementing this. The simplest would be to open an URL connection to the server, which then sends back structured data (possibly XML or JSON); this would amount to a RESTful approach. Using the full-blown
SOAP stack and its associated APIs (SAAJ, JAX-WS) is also possible, of course. So I'd say the client side does not present a problem.