Research On Web Service Adaptability Composition Based On STS

With the advent of the era of high-tech explosion,service-oriented architecture has become more mature and has gradually become the mainstream software form in the Internet era.At the same time,the number of Web services on the Internet has increased dramatically,and single-function Web services have not meet the diverse and personalized needs of users.Therefore,it is necessary to integrate existing services through service composition,which is combined into new services that meet demand.However,in the process of service composition,since services often come from different development environments.,the operation names,parameters,calling order,return values,etc.defined in the service interface are different.So that a large number of incompatibilities have appeared in the compatibility check in the process of service composition.For these incompatible services,if you take a complete round-off approach,you may not be able to find the required service,service adaptation technology emerges as time requires.It has become a hot issue worthy of discussion how to improve the accuracy of compatibility check and adaptation technology in the process of service composition.Web service composition has achieved a lot of results,but there are still problems to be explored.First,most service interface-based description models don't take into account interaction information and internal behavior(?)value passing;Secondly,the compatibility concepts involved in most studies are too singular;Thirdly,compatibility checks often return only Boolean As a result(only compatible and incompatible),which is impossible to distinguish whether it is completely incompatible or partially compatible,and no further quantitative processing is performed for the incomplete compatibility.Meanwhile,for incompatible services,how to generate an adapter to make the service interact correctly is also a question.In view of the above problems,this article will model the behavior of Web services,and explore all aspects of service description,compatibility issues,and adaptation technologies.First,in order to improve the standardization of the service message interface and the correctness of the interactive behavior,this article proposes a graphical and more intuitive service view that combines external interfaces and internal behaviors,while using the Symbolic Transition System(STS)Model web service behavior.Secondly,according to the analysis,induction,and summary of compatibility,this paper proposes an internal transition processing strategy,four compatibility concepts,and a compatibility check framework corresponding to theconcepts,which can meet the compatibility judgments of different types and accuracy requirements.So that compatibility checks are more flexible.And,we propose a general framework that can automatically measure the compatibility of service interfaces based on different compatibility concepts.Meanwhile,for incompatible services,a mismatch list is also provided to facilitate the subsequent adaptation to quickly find which parts of these services do not match.In addition,we need to judge whether the service can be adapted according to the compatibility measurement results and the mismatch list.If it is adaptable,the interaction mapping between services is expressed as a synchronization vector,and the vector between The temporal relationship is transformed into an adaptation contract.Finally,the causes and conditions of mismatches are analyzed,and corresponding countermeasures are designed according to these different reasons.In addition,we designed an adaptation algorithm that can automatically generate adapters based on the adaptation contract and adaptation countermeasures,so that the newly generated adapters can coordinate originally incompatible services and enable correct interaction between services.