Research And Implementation Of Executing Architecture For Web Services Composition Based On Mobile Agent

The explosive growth of interconnected computing technologies enabling new environments where ubiquitous information access anytime will be a reality. Mobile equipment can conveniently visit various resources and complete various operations in the new environment. Currently, some new Web Services are being offered to users of mobile devices, for example, cell phones and personal digital assistants. But several obstacles still hinder the seamless provision of Web Services in mobile environments. Examples of such obstacles are: throughput and connectivity of wireless networks, mobile computing components limited supply capacity, limited computing resources of mobile devices and risks of communication channel disconnections. It happens that a user has to postpone operations. One of the methods to solve these issues is that a user should be able to search for additional facilities from internet when needed and invokes these facilities remotely.With the fast development of Web Service technology, it is possible to use Web Services composition to satisfy the application requirement. Since Web Services are unstated and also lack corresponding coordination mechanism, they can not be integrated properly. Therefore, it becomes the common concerned problem in industrial and academic world how to break this isolation restriction, to reuse the existed Web Services and to compose these Web Services to generate new Web Services to satisfy the application through the way of automation and management.Considering the above deficiencies and integrated with the advantages of Mobile Agent, this thesis designed a Mobile Agent-based architecture for composite Web Services provisioning in hybrid environments composed by fixed device and mobile device based on the analysis of the current research of Web Services and their composition. The architecture can at first decompose it into several interdependent task pieces and then assign them to several Mobile Agent to carry out the distributive execution. I designed soft agent symbolizes user, service provider and resource provider in this architecture. What's more, the use of agent provides such a basic architecture, it can deal with exception disconnect situation when service begins to connect. Finally, in view of the performance of complicated transaction of business processes, this paper also have provided the research and implementation for the schedule execute mechanism of Web Service composition system. The architecture integrates a service execute orchestration plan and transaction handle mechanism in order to choose dynamic computing resource and deal with transaction according to coming executed service.