The JAX-RPC API

JAX-RPC defines a set of classes, interfaces, principles, and mechanisms for making SOAP-based RPC calls. The main parts are

• Type conversion between Java types and XML types— For simple types, such as strings and primitive types, very little work is required. More effort is required from either the tools or the developer when mapping more complex types between Java and XML.

• Mapping between SOAP operations defined in WSDL and Java remote method calls— Essentially, WSDL interfaces are represented in Java by Remote interfaces.

• The server environment and how calls are received and directed— The receiving Java class has access to particular information about the SOAP call provided through a service context. The lifecycle of a servlet-based service is defined.

• A client- and server-side SOAP message handler mechanism similar in concept to servlet filters.

• Client programming model describing the relationship between interfaces and stubs, and how these are obtained in different environments such as J2SE and J2EE.

The essential principle is that JAX-RPC tries to make the development of SOAP-based clients and servers fairly simple and intuitive for Java developers. To start your journey through Web Services, the first example is a simple, servlet-based JAX-RPC service and a standalone client for it.