XML, Web Services, and the Data Revolution

By Frank  P.  Coyle

Oracle has adapted its database products to fit the demands of the Web services world. The Oracle9 i Web Services Framework provides an infrastructure that supports the development, management, and deployment of Web services to portals, exchanges, and other Internet and mobile applications. It uses XML as a common access method.

The Oracle9 i Web Services Framework uses a Web services client library written in Java. The client library includes connection drivers for linking to Web services repositories. Oracle9 i Web-service descriptors can be published as WSDL in other UDDI registries to support Internet-wide service discovery, and services described using WSDL can be imported into the Oracle9 i Web Services Registry.

Adapters

Oracle uses adapters to extend the basic framework. For example, specialized adapters may be created to build connections with legacy systems. Some of the adapters include

• Input and output adapters for specifying XSLT style sheets to transform service requests to the XML format required by a service

• Protocol adapters to connect with Web services using HTTP, HTTP over Secure Socket Layers, Java Database Connectivity, Simple Mail Transfer Protocol, and SOAP

• Execution adapters to execute service requests in a particular flow, minimally relaying a request to contact a resource provider, and relaying the response. Standard adapters include simple, compound, failover, and conditional.