The JAX-WS web services support is represented by the JaxwsHandler, which extends HttpHandler functionality, so each time JaxwsHandler is getting called, it passes control to JAX-WS core, which in its turn calls correspondent web service.
A JaxwsHandler could be associated with only one web service, which could be passed to JaxwsHandler constructor.two ways:
Web service instance, so default configuration will be used;
WSEndpoint, which may contain customized web services configuration, like binding, WSDL location etc...
A JaxwsHandler is able to process not just web service's operation calls, but also meta data requests like requests for web service's WSDL and XSD. So if you register JaxwsHandler to serve web service on http://localhost:8080/addservice, the WSDL of the service would be published at http://localhost:8080/addservice?WSDL.