Today's IT organizations have tens of applications and services that perform some well-defined tasks such as inventory, billing, expense reporting, and order entry. With the evolution of Internet and e-business, enterprises have started to think about how different applications in a disconnected mode can work independently but at the same time be a part of an information workflow process.

RPC-style Web services aim to expose a business object as a Web service interface described by WSDL (Web Services Description Language). On the other hand, document-based Web services are based on the exchange of XML documents between two parties. The Web service receiving the document is responsible for performing actions based on the content of the XML document. The benefits of using a document-style Web service are:

This article takes a look at SOAP Message handlers and how JAX-RPC supports SOAP Message handlers and its usage scenarios. First, some of the terminology: a SOAP Interceptor takes raw SOAP message as input and, before processing the message, modifies the SOAP message or adds some additional information to it, and then returns the SOAP message as output.

The notion of distributed computing has been evolving for a long time, during which we have been building business solutions by integrating various systems and platforms. Typically, these interactions are characterized by accessing and invoking clearly defined interfaces using well-known communication mechanisms like Remote Procedure Calls (RPCs) or by using message-centric protocols. Web services is probably the easiest distributed computing paradigm available today. Given the familiarity to RPC and message-centric invocation models, we need the flexibility of using both these models in the Web services invocation frameworks.