Tech Check: Putting SOAP Tools to Work

Computerworld - For users of the new breed of Web services tool kits, there's a certain sense of deja vu. Simple Object Access Protocol (SOAP) is, after all, just another remote procedure calls (RPC) protocol; Web Services Description Language (WSDL) is just another interface definition language; and Universal Description, Discovery and Integration (UDDI) is just another directory service.
These new variations on old themes are wildly popular, and for good reason. XML flowing over HTTP makes integrating applications in and across enterprises much more open and flexible than ever before. Web services tool kits have rapidly converged on a core set of functions: They can integrate SOAP messaging with programming languages and application servers, automate the creation and use of WSDL wrappers and test harnesses, and help debug distributed Web services.
Given a rich assortment of competent tool kits, the choice for a developer quickly narrows depending on language and environment. For .Net shops, Visual Studio .Net is the clear choice, though competition will likely increase. For Java shops, the choice is influenced by the Web application server in use and by the application itself.
A Taxing Experience
ASU Solutions Inc., a Santa Clara, Calif.-based applications developer, used IBM's Web Services Toolkit in conjunction with WebSphere Studio Application Developer to create the ASU eTax Server. This is deployed as a Java 2 Enterprise Edition application to large counties with robust IT infrastructures and is hosted on behalf of smaller counties. The service lets both individuals and institutions pay property taxes via the Web.
With Web services, it's possible to decouple a service like ASU's payment engine from an application's user interface, and ASU does just that. Individuals who use the eTax Server may access it through a Web browser, by way of a translation layer that renders the XML interface as an HTML application. Alternatively, notes Bojan Vukojevic, ASU's director of technology, individuals can access the service directly from a rich client, such as the SOAP-aware version of Excel in Office XP.
Many tax payments are made by banks aggregating funds from several escrow accounts into single payments. Boris Oak, director of sales and marketing at ASU Solutions, says having county clerks process those payments is expensive and prone to errors, but Web services can dramatically streamline the job. Also, Vukojevic says, the UDDI wizard that ASU provides lets counties publish their payment services in a directory, so a mortgage company can look up counties and batch payments on multiple properties, for example.
One thing not yet standardized for Web services isthe all-important security context for transactions. ASU has had to create its own authentication system.
Udell is a consultant and writer in Keene, N.H.