Jakarta XML RPC (JAX-RPC; formerly Java API for XML Based RPC) allows a Jakarta EE application to invoke a Java-based web service with a known description while still being consistent with its WSDL description.
JAX-RPC 2.0 was renamed JAX-WS 2.0 (Java API for XML Web Services).
[2] The core API classes are located in the Java package javax.xml.rpc.
It works as follows: 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.