Summary of Java API for XML-based RPC (JAX-RPC): A Primer

Target Audience

Software engineers who are familiar with Java, RPC, and XML.

Type of Document

It is meant as a technical reference article with source code examples to introduce a developer to a new API.

Summary

JAX-RPC is a Java API for performing RPC calls using XML as the communication protocal. SOAP defines the how to encode and send the information in XML. Web Service Description Language (WSDL) allows you to descrive services as a set of endpoints that handle SOAP messages. A user defines service endpoint with a Java interface. WSDL can be translated to a Java interface directly. The end point can be implemented as a stateless session bean or as a servlet. In this example the implementation is deployed as a session bean within an EJB container. WSDL is used to describe the service so that others can connect to it. It will note the port and binding of the services like binding the port to SOAP over HTTP. JAX-RPC allows Java code to call non-Java code and vice-versa. The service can then be imported and use either a generated stub class, dynamic invocation interface, or a dynamic proxy. Any of these 3 methods can be used to invoke the service.

Conclusion

JAX-RPC provides an API to implement XML-RPC from within Java. It supports compatibility with other languages by translation to and from WSDL. It also allows several different methods of invocation that support different levels of abstraction. The author does require lots of concepts to be known by the reader. He also skips through some of the steps of setting things up. It would be nicer of the author showed the setting of up two systems running the J2SE to have a service work between with full code samples instead of just snippets of code.