Depending on whom you ask, Web services might be simply the latest evolution of application integration technology, or it could be a revolutionary new application design model. But whatever your opinion of the significance of the new Web services paradigm, you have to admit that the industry is rather abuzz over it. In this article, I'll provide you with some links to general resources, service location information, and development tools so you can find out about this new technology yourself.
Getting up to speed (and staying there)
Web sites that offer information on Web services development, implementation, and architecture are cropping up all over. Here are links to a few sites that fall into this category. Each site also maintains a resources section with links to other informational sites.
- IBM's developerWorks Web services zone brings together quite a few links to articles and news regarding Web services development. You'll also find a good five-part article discussing the issues that adopters of this new technology are likely to face.
- Web Services Architect is an online journal aimed at Web services developers and architects. Here, you'll find industry news and a fairly lengthy resource list, along with a new original article about once a week.
- O'Reilly XML.com publishes Web services articles pretty frequently. The trouble is, there's no dedicated section for those articles on the site, so you'll have to look for them yourself.
- Finally, we have SoapWare.org, a no-frills information directory for SOAP developers. Links are organized into seven folders: Specifications, Implementations, Services, Communities, Tutorials, Articles, and News. The directory is updated frequently, so you'll want to check back often.
Finding a service to play with
Whether you are just playing around or building bona fide production clients, you're going to need to hook up with the right service. Fortunately, a large number of companies and organizations have already published Web services for use in applications. These range from the rather mundane personal information manager (PIM), credit card validator, and currency converter services to decidedly esoteric examples of the technology, such as the Nucleotide sequence retrieval, Shakespearian insult generator, and California highway traffic conditions services. So the Web service is out there; the trick is locating it.
Luckily, a few Web service listing sites have sprung up recently.
- XMethods.net provides a long listing of free and sample Web services hosted on a variety of platforms all over the world. There's also a new listing e-mail notification list.
- SalCentral is a "Web services brokerage" that hosts a large, searchable database of free and pay-per-use services. SalCentral also offers e-mail notification of significant changes to selected Web services via its Watch feature.
- In some situations, you may want to programmatically discover available services. For that, you'll likely turn to the Universal Description, Discovery, and Integration (UDDI) protocol, which is maintained by the UDDI Community.
- Also falling under the heading of Web services search engine is SoapClient's UDDI Browser, which enables you to perform text searches for services.
- If you don't mind being able to find only Web services built with Microsoft tools, you can always check out the ever-expanding list of Web services at GotDotNet.com.
The right tool for the right job
Implementing a Web service involves the marriage of a list of technologies that looks like a Scrabble game board following a small tornado: XML, HTTP, WSDL, SOAP, and possibly more. Some development environments, such as Visual Studio and Delphi, will build some or all of these disparate pieces for you, but many don't. There's a niche market for developing tools that automate the process of exposing functionality as Web services.
Here are a few tools currently being offered.
- Cape Clear offers a product called CapeStudio, which it calls a "Rapid Application Development (RAD) environment for creating Web Services and XML-based applications." CapeStudio includes graphical XSLT and WSDL generators and a UDDI Registry browser for locating available services.
- VelociGen's VelociGenX spans the gap between development tool and run-time environment. You can experiment with it via VelociGen's free Web Services Sandbox.
- GLUE is a 100 percent Java tool for publishing Web services that includes an embedded Web server and servlet engine, WAP support, and dynamic XML mapping, among other features. It's free, even for commercial uses.
- Apache SOAP is a client- and server-side tool for accessing and implementing Web services on the open source Apache Web server. It's based on IBM's SOAP for Java.
Don't be left out
Web services technology has benefited by recent backing from industry heavies like IBM. You probably don't want to be left out in the cold. I hope that armed with good resources like these, you won't be.
What's your favorite authoring tool?
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