A Semi-Automatic Approach to Composite Web Services Discovery, Description and Invocation

With the popularity of the Web services technology, more and more software systems’ functionalities become available by being published and registered as Web services. Registered Web services need to be dynamically combined to form “composite services” when individual “simple services” fail to meet service requestors’ complex service needs. In this article, we propose a semi-automatic approach to composite Web services discovery, description and invocation. We present an intelligent registry with constraint matching capabilities to support composite service discovery and description. It provides a user interface to interactively compose a service request. It then uses a semi-automatic mechanism and a search algorithm to construct a composite service template that satisfies the request. The operations of the template are bound to registered service operations by constraint matching subsequently. The resulting composite service is specified in the Web Services Flow Language. A composite service processor is designed to execute composite services by invoking the component service operations of various service providers.