Automatic Web Service Composition Based On Multilevel Semantic Interface Matching

Web Services is taking the Web to the Internet-based calculating platform.And Web services is the latest attempt to revolutionize large scale distributed computing. With XML based standards like UDDI,WSDL,and SOAP,they are touted as the tools for universal connectivity and interoperability of applications and services. With the growing popularity of Web services,there arise issues of finding relevant services,especially with the possibility of the existence of thousands of Web services. But the function of a single Web service is very limited.we need to compose those Web services to obtain more potential functions. Current standards have focused on operational and syntactic details for implementation and execution of Web services.This limits the search mechanism for Web services to keyword based searches.Several years from now when we are expected to have thousands of services,current syntactic search along with manual intervention would be untenable.Research in the Semantic Web area has shown that annotation with metadata can help us solve the problem of inefficient keyword based searches in the current web.This concept of annotation can be extended to Web services to envision Semantic web services.Semantically described services will enable better service discovery,allow easier interoperation and composition of Web services.The Web Services Description Language (WSDL) is lack of semantic meanings, so it is hard to realize interaction and composition in semantic level. In this paper, we present a semantic-based description method and extend wsdl with those descriptions to realize the semantic mark on the Web services.Although there are already many description languages on the semantic Web services, such as owl-s etc.But we directly extends the WSDL to make it more conform to the industrial standard. Based on those semantic marks,We propose the layered composite model and composite algorithm. The composite arithmetic in this paper can find the potential Web services automatically and dynamically through calculating the similarity between the services' interfaces in different layers. And we also provide the flow diagram of the whole composition and give the matchmaking algorithm. With this algorithm, the services can find the potential Web services automaticly.Finally we give a software system of markup semantic Web services.lt can provide semantic meanings to the WSDL files,and translate these information to the database model.The matchmaking algorithm then can use these information to look for and compose those services,and provide the composite plan in the end.