Using web services data in a report
Web services make software functionality available over the internet, using open and standard protocols, in the following manner:
A web service defines a structured format for requests for its service and for the response the service generates.
An application—a BIRT report, for example—makes a request for the web service over the internet.
The web service performs an action and sends the results to the application.
The action can be calculating a monthly mortgage payment, retrieving stock quotes, converting currencies, getting the weather forecast for a particular city, or finding books by a particular author. If a report needs to present data that can only be generated by a program, you can save time and effort by looking for a web service that does the programming work and returns the data you need.
Web services use the following standard protocols:
WSDL (Web Services Description Language) to describe the available services or operations provided by a web service
SOAP (Simple Object Access Protocol) to transfer data
XML to structure the data
Because web services are written and maintained by other developers, always examine the web service definition to ensure that the web service does what you need. You should also verify that the WSDL document is well formed. Remember, too, that you have no control over web services created by others, and if a web service your report accesses is modified significantly or removed, the functionality no longer works in the report.