Semantic Tools for Web Services

Overview

Requirements

Download

FAQs

Forum

Reviews

What are Semantic Tools for Web Services?

Semantic Tools for Web Services are semantics-based, semi-automatic Eclipse plug-ins for Web service matching, discovery, and composition. Software developers can use these tools to find and compose existing software (represented as Web services) in order to implement new or changed business processes. Internet technology (IT) consultants and developers can use them to integrate new or legacy business applications that are represented as Web services.

The tools are now available as an Eclipse plug-in that can be installed on IBM's WebSphere® Integration Developer (WID) 6.0.1. Specific features of the tools are as follows:

• Web Service Interface Matching: Using this feature, one can semi-automatically map the interfaces of two given Web services (WSDLs). This scenario typically occurs when two legacy applications (each of which is represented as a Web service) are to be integrated with one another. This feature identifies the semantic similarities between the descriptions of the services by semi-automatically resolving the lexical, structural, and syntactic differences and creating the interface maps. (For example: An IT consultant could use this feature to resolve the differences between the purchase order messages exchanged between two companies).
• Web Service Discovery: This feature is useful if one is searching for existing Web services that can match a request from among a large set of Web services in a registry or repository. This scenario typically occurs when one is trying to reuse an existing piece of functionality (represented as a Web service) in building new or enhanced business processes. (For example: An IT consultant trying to implement an RFID checkout Web service for a new customer may want to find out if someone else in the organization has already implemented such a service for a different customer.)
• Web Service Composition: This feature is similar to Web service discovery. In the case of Web Service discovery, the system finds single services that match a request (if they exist). The composition scenario demonstrates how multiple services can be composed to match a given request. The results include both direct single service matches (if they exist) and compositions of services (output as BPEL flows). This scenario typically occurs in business process integration when semantic or data mediations are necessary for matching the interfaces of two given services. (For example: A plain-text purchase order may have to be transformed into a digitally-signed and encrypted document before it can be sent to a supplier.)

How does it work?

Semantic Web techniques are used to resolve domain-specific similarities. For example, the concepts used in a given domain (such as retail industry, health-care industry, etc.) and the relationships among them are modeled as a domain ontology. The Web services are annotated using semantic annotations from the domain ontologies in Web Services Semantics (WSDL-S) format. Then the ontological similarity of the semantic annotations associated with Web service descriptions is derived by inferring the domain ontology.

Matches from the two approaches are combined to determine an overall similarity score to help assess the quality of a Web service match to a given request. In cases where single services do not match a given request, the system can compose multiple services by employing artificial intelligence (AI) planning algorithms in order to fulfill a given request.

The WSDL-S mechanism for annotating Web services with semantics is based on an approach developed jointly by IBM and the University of Georgia. This approach was submitted to W3C in 2005 and is now the basis for the work of the new Semantic Annotations for WSDL (SAWSDL) Working Group.