This chapter, and the Service Directory pattern presented in it, is the final pattern that specifically addresses Web Services, their design, and how to use the Web Service environment. In this chapter, you learned about the uses and capabilities that service directories offer. You also looked at a specific service directory implementation, UDDI, to examine how it fills out the generic Service Directory pattern.
UDDI presents a robust mechanism for representing business entities, as well as the business services that a business entity offers. You spent most of the chapter discussing how to publish information in UDDI and some time discussing how to locate information in UDDI. Because of the robust set of mechanisms to represent businesses and services, it is useful to understand the data structure within UDDI because the location operations on UDDI simply allow you to combine the data structure elements into queries and extract the information based on the portions of the data structure that you specify.
For the case study, you published a business entity that represents the P.T. Monday Coffee Company and a business service that represents the product collection. You also published a tModel to describe the product collection. You associate the business service with the tModel through a binding template. Others can use the tModel to implement their own product collection; this reuse makes it easier to integrate systems from different vendors .
UDDI is not a part of the Apache Axis Web Service environment. Axis gives your applications the infrastructure that you need to communicate between Java programs and Web Services and from Web Services to service implementations . A broader community supports UDDI. You used the UDDI4J package from IBM and the IBM UDDI test registries to play with service directories. Before you can successfully deploy the sample applications, you must register with the IBM test registry, located at http://uddi.ibm.com/testregistry, and alter sample code to use your user ID and password.
Starting with the next chapter, the book discusses specific ways to offer and consume Web Services with the assumption that you know enough about Web Services to understand the mechanics behind them.