Research Of Technology Of Online Evolution Based On Web Service

Now, many software systems need to provide uninterrupted service to customers, therefore on-line evolution of software has become an important research topic in today’s software maintenance field, the ability to provide uninterrupted services is becoming an important indicator of measuring the software system. As the research of service-oriented architecture (SOA) becomes more mature, there are many systems which are constructed by service component, to realize on-line evolution by service granularity can not only improve soitware reusability, but also the characteristics of independent and evolution of service itself, which can decrease the cost of on-line evolution of software.This paper first introduces the concept and classification of the on-line evolution, and also introduce several development stages of software evolution according to the particle size of evolution, from procedure-oriented to object-oriented to component-oriented to service-oriented, and also introduces the characteristics and relevant research results of each development stage of software evolution. Secondly, preliminary introduce the definition of Web services, features, architecture, protocol stack and core technologies, and also introduce the concepts of service-oriented architecture (SOA), superiority and the relation with Web services. After this introduce the impact on the process of Web service on-line evolution, and then introduce problems of on-line evolution need to face, putting forward the corresponding solutions, focusing on researching and solving service call transparency of Web services on-line evolution, providing a theoretical support for the on-line evolution by service granularity of system. Again we can use online commodity trading system as an example to realize on-line evolution based on Web service, and first talk about the overview of the system and the main function modules, then give the overall architecture of the system on the network, and then according to the analysis of technology theory before, updating Web services architecture, therefore constructing the system architecture, detailed designing various functional modules, database tables, and Web services. Finally, realize Web service layer of system query commodities module by code, including Web service class constructor, Web services deployed on the Axis server, the client calls the Web service, and simulate implementing the on-line evolution of Web services, providing a new Web service reference to the client through the redirection service class.This paper describes technical problems of on-line evolution based on Web service, and detailed introduces the service invocation transparency problem of the on-line evolution process, giving solutions and related technologies, finally uses the online commodity trading information service system as a platform to verify the feasibility of the idea.