Integrating heterogeneous web service styles with flexible semantic web services groundings

Semantic web services are touted as a means to integrate web services inside and outside the enterprise, but while current semantic web service frameworks— including OWL-S [1], SA-WSDL, and WSMO [2]—assume a homogeneous ecosystem of SOAP services and XML serialisations, growing numbers of real services are implemented using XML-RPC and RESTful interfaces, and non-XML serialisations like JSON. Semantic services platforms based on OWL-S and WSMO use XML mapping languages to translate between an XML serialisation of the ontology data and the on-the-wire messages exchanged with the web service, a process referred to as grounding. This XML mapping approach suffers from two problems: it cannot address the growing number of non-SOAP, non-XML services being deployed on the Web, and it requires the modeller creating the semantic web service descriptions to work with the serialisation of the service ontology and a syntactic mapping language, in addition to the knowledge representation language used for representing the semantic service ontologies and descriptions. Our approach draws the service’s interface into the ontology: we define ontology objects that represent the whole HTTP message, and use backwardchaining rules to translate between semantic service invocation instances and the HTTP messages passed to and from the service. This novel approach is based on several principles: