This chapter provides an overview of a few future standards that affect Web services and the Java platform.
The WSDL-based Web service description does not provide the ability to define asynchronous, long-running interactions between Web services. Web service composition is a means to define business processes that involve Web services. WSCI and BPEL4WS are two competing specifications for Web service composition.
SOAP is designed to be a basic messaging infrastructure protocol for Web services and to be extended so that more complex message exchange patterns can be layered on top of it. One such pattern is message routing, where a SOAP message is directed along a defined path before reaching its destination. WS-Routing takes advantage of the SOAP header processing model and proposes a simple specification that enables SOAP message routing.
Finally, we looked at two JSRs that will prove useful for Web services on the Java platform. AML descriptor files, special method names, and so on are slowly complicating the development and deployment of Web services on the J2EE platform. The Web services metadata JSR (JSR-181) proposes a new annotation for Java classes, so that Web service tools will be able to develop and deploy Java Web services more easily.
Bringing Web services to J2ME is an important step in bringing enterprise services to mobile devices. JSR-172 proposes a lightweight J2ME Web services model that addresses XML processing and XML RPC.