JavaAPI for XML-based RPC (JAX-RPC) allows a Java application to invoke a Java-based Web Service with a known description while still being consistent with its WSDL description. It can be seen as Java RMI over Web services. JAX-RPC 2.0 was renamed JAX-WS 2.0 (Java API for XML Web Services). JAX-RPC 1 is deprecated with Java EE 6.
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 advantage of such a method is that it allows the Web Service to be implemented at server-side as a Servlet or EJB container. Thus, Servlet or EJB applications are made available through Web services.