Research Of Semantic Graph Based Web Service Composition In SOA

Service-Oriented Architecture (SOA) is a kind of software framework which connecting independent functional entities that completes specific tasks, accounting for the needs of Business Integration. SOA is a component model which linking different function modules (called services) of application procedures through a well defined interface and contract. Those interface is defined in a neutral pattern, which is independent of the hardware platform , operating systems and programming languages. This makes services in such system interact with each other in an integrated and universal manner.At present, mainly based on SOAP, WSDL, OWL-S, UDDI technology, SOA achieves universal description, discovery and integration of Web services. However, because of the lack of semantic information, it is primarily through keyword to complete the combination of service traditionally, rather than a way that can be interpreted by computer. Meanwhile the development of semantic web provides a chance for web service. Using semantic web, all information on the network has their semantics. Thereby, the machine can understand and deal with the information. Combining the character of loose couple of web services with the semantic information provided by semantic web, we can match, find, invoke web services automatically, so as to build and execute business process dynamically. As a result, we can integrate the application systems from different enterprises better.On the background of the construction of hospital information system, this paper presents the system architecture of Semantic Web Service-based Application Integration Platform (SWSAIP). In the platform, application systems are abstracted and wrapped as web services. These services are described semantically and published in the registry center of the platform. Applications propose their requests through the platform. Appropriate concrete services are discovered and matched dynamically by the platform. Then business systems are selected and executable business processes generated dynamically.With analysis of the overall framework of SWSAIP, this paper proposed eXtensive Semantic Web Service Description Model(X-SWSDM) to model web service from functional, semantic and logical aspect, and an method of service composition based on inputs , outputs , preconditions and effects. Then translate service description into semantic graphs, checking whether it satifies user request. This increase the automaticity and veracity of service composition.Finally, the paper demonstrates an operation flow of the hospital to illuminate that this system can finish the composition of web services.