Locating a Web Service

If you re looking for a publicly available Web Service, there are two sites we like that provide this information: XMethods (http://www.xmethods.net/) and SalCentral (http://www.salcentral.com). When developers create a Web Service, they often register it on these sites. As time passes , more services will be listed in the UDDI directories because that s where they really belong. These web sites include complete descriptions, implementation information, etc., about each Web Service. Some of the services listed are gamelike, such as Letter Soup and Shakespeare, but most are business solutions such as Stock Quotes, View Area Codes For City, Real Time Car Rental Quotes, and so forth. Many of the publicly available Web Services charge for the use of their service; some charge over a threshold, such as 100 quotes a day. When you use either site, you can search for a specific type of Web Service. For example, if you search for stock quotes on SalCentral, a list of available services is displayed.

This site tells whether the Web Service is free or if it charges per use; you can drill in for more information about each Web Service. Note that many of the services (on Salcentral) listed show that they are FREE, but if you drill into the service, you ll find that the trial is free and that the use of the Web Service does cost money, typically per transaction. To determine whether a service is truly free, you must drill into the specific service for the details (i.e., read the fine print). On the XMethods site, once you select a specific Web Service, you ll see details for the delayed stock quotes Web Service.

Querying from UDDI

If you click UDDI in the Generate Web Service Stub/Skeleton or anyplace else, you will walk through a seven-step wizard for UDDI searches. Step 1 is simply a confirmation or informational step. In Step 2, you ll choose the UDDI directory that you wish to use (i.e., Oracle, Microsoft, or IBM) or you can click Create to add a new UDDI directory. In Step 3, you ll need to select whether you wish to search the directory by name (i.e., White Pages) or category (i.e., Yellow Pages). If you search by name , in Step 4 you ll type the text that you wish to search for and whether you wish to find an exact match and/or a case-sensitive match. Wildcards (i.e., %) can be used in your search. If you search by category, in Step 4 you ll be presented with a taxonomy of items to choose from based on the taxonomy classification you choose. Taxonomy classifications include UDDI types (i.e., based on the transport protocol, SOAP-based, or WSDL-based), NAICS (North American Industry Classification System, which includes breakdowns such as accommodations and food, agriculture, etc.), ISO 3166 (classifications are broken down by geographic area), or UNSPSC (United Nations Standard Products and Services Code, which uses the UNSPSC goods and services classifications). You can pick multiple categories. Once you select a category (or more than one), you can click Next. During Step 5, the UDDI directory is searched based on the search string or categories you selected in Step 4. During this step, you ll need to be connected to the Internet. If no matches are found, you ll need to go back to the prior page and change your criteria. For each match that is found, Oracle JDeveloper 10 g will confirm whether a WSDL file exists for the Web Service and it will pull a description (if one exists) for each Model Name. You ll need to select a Web Service that is of interest to you. In step 6, you ll choose which services you wish to include in your stub. In the final step, you ll see a full description of the Web Service, the binds, and more information. This step is merely a confirmation step. From here, you simply continue creating the Stub as you did when you created a stub with the URL of a WSDL file.

If you have a favorite (or different than Oracle, Microsoft, or IBM) UDDI directory that you wish to use, you can add additional UDDI directories through the Oracle JDeveloper 10 g interface, also.