Java API for XML-based RPC (JAX-RPC) allows invoking from a Java application a Java based Web Service with a known description while still being consistent with its WSDL description. It can be seen as Java RMIs over Web Services. JAX-RPC 2.0 was renamed to JAX-WS 2.0 (Java API for XML Web Services).

It works as follows:

A Java program invokes a method on a stub (local object representing the remote service)

The stub invokes routines in the JAX-RPC Runtime System (RS)

The RS converts the remote method invocation into a SOAP message

The RS transmits the message as an HTTP request

The advantage of such a method is that it allows the Web Service to be implemented at server-side as a Servlet or EJB container.Therefore, Servlet or EJB applications are made available through Web Services.