【作者】 张磊；

【导师】 刘磊；

【作者基本信息】 吉林大学 ， 计算机软件与理论， 2011， 硕士

【摘要】 随着因特网的快速发展,各种文档信息及应用程序等都可以从网上轻松获取。Web服务就是各种分布在网络上,以网络技术为基础,用于完成某种特定功能的应用程序。Web服务的生命周期一般包括服务发布、服务发现、服务选择、服务组合和服务调用这五个流程,其中服务组合是Web服务技术研究及应用的重点和难点。Web服务组合主要是通过合成技术,将若干个功能单一的Web服务,组合成可以满足服务请求者复杂功能需求的过程。Web服务组合验证是Web服务组合的一个重要组成部分,它在实现Web服务组合、确保组合后Web服务正常执行过程中起着关键作用。Petri网是系统建模和分析的一种有效工具,它对分布式系统和结构中的进程或组成部分之间的各种关系有较强的描述能力。本文采用Petri网作为分析工具,对基于服务行为Model的Web服务组合的有效性进行验证,通过分析组合Web服务可以判断其是否存在死锁以及能否正常结束。本文首先介绍语义Web服务的基础理论,然后介绍Petri网的相关基础知识,随后给出从语义Web服务中OWL描述的行为Model信息转换为Petri网模型的过程,在此基础上,利用Petri网的性质,实施Web服务的Petri网表示的组合操作,借助Petri网的转移矩阵来对组合Petri网进行组合验证,最后根据验证结果来分析组合Web服务是否存在死锁以及能否正常运行结束。由于在服务组合过程中采用的Web服务行为Model信息更能体现出Web服务组合的细节,如服务输入输出之间的顺序和输入输出的前提条件和执行后的效果等,因此基于Web服务行为Model的Web服务组合验证更具有准确性。更多还原

【Abstract】 With the development of Internet technology, not only the Web page documents can be accessed by the Internet, a variety of application programs provided by the companies or organizations can be accessed and employed. In the beginning of 21st century, SOA became popular because of its several advantages, such as:measurability, loosely coupled, standardization and interoperability. Web Service is the technical support of the majority of SO A. In 2001, Tim Berners-Lee, founder of the Internet advance the concept of semantic Web.Semantic Web service is the combining technology of Semantic Web and Web service. The clear semantic information of Semantic Web services improves the efficiency and accuracy of Semantic Web service discovery. OWL-S (Web Ontology Language for Services) which is the Semantic Web service description language of Service Model information is used by Petri nets for Verification of Web services composition based on behavior.Taking the reusability of semantic Web service into account, Web service generally has specific function, a single Web service can not meet the complex application of service requests, which resulted in Web service composition. Since the independence and autonomy of Web services, some Semantic Web services composition is not reliable. And it will waste unnecessary time and economic consumption if Web service composition is found not to work abnormally until the composition is invoked. It is the key to ensure the normal execution of Web services composition that verification of the combined service before invocation.In order to solving verification of Web services composition, Petri net is used to verify composition of Web service based on behavior. The first characteristic of this approach is the using of Petri net. Petri net can be used for distributed system modeling and analysis, and Petri net has the advantage of the strong ability to describe the relationship between the various structure components of system or process (such as:sequence, concurrency, conflict, and synchronization). In addition, Petri net has the same semantic consistency with its transitive matrix. The purpose of running simulation of Petri net can be achieved by the transitive matrix operation. The second characteristic of this paper is to composite Semantic Web Service based on service behavior of OWL-S description. Web Service Composition based on the service behavior involves the service of the relationship between the atomic processes, and the order of service input and output, precondition and effect after the execution. Therefore, the verification of Web Service composition Based on Behavior of services is more accuracy.The verification method of this article is that modeling semantic Web service based on service behavior as Petri net first, related conversion modeling theory is referred to some papers and is improved, and then composing Petri nets which semantic Web services are modeled as. On the basis of this, the labeled place transitive matrix is used for verification analysis of Petri net, the results of the verification analysis can tell whether the composition of Web service is deadlock or there are correct results. The specific method is to run simulations on the Petri net through the multiplication of the labeled place transitive matrix and the state set of place after the conversion from Web service composition to the Petri net. When the state set of places is no longer changed, the result of verification analysis for Web service composition can be judged according to the value of token state of the place.更多还原