Semantization of Legacy Web Services: From WSDL to SAWSDL

Abstract

This paper presents a process and a means aiming at producing and attaching semantic descriptions to a large number of existing Web services, the use of such means avoiding knowledge of complicated languages (e.g. OWL) and avoiding the construction of complete ontologies. The purpose of Semantic Web services is to make service definitions machine-understandable by describing their capabilities, inputs and outputs, and diverse constraints, in a formal language: when sufficiently rich, these descriptions allow the discovery of services and the creation of novel services compounds with little or no direct human intervention. As a main approach for depicting these machine- readable descriptions, SAWSDL represents an extension of the syntactical description format WSDL by defining an annotation mechanism that allows to describe semantically web services in terms of concepts provided by a domain ontology, and by providing these semantic annotations embedded into WSDL documents. Instead of writing manually annotations or loading ontologies to align the terminology by numerous drag-and-drops, the paper describes a simple process: final SAWSDL descriptions are produced automatically from original WSDL documents, no RDF/OWL skill is required, and internal contents of manipulated documents (e.g. XML/WSDL, OWL/RDF) have not visible to the user.