Design And Implementation Of Web Service System Based On Workflow

The research of web service involves many key topics,such as discovery of web services, dynamic composition of web services,web service composition analysis,implementation of web service composition etc.Those key topics compose a framework for the research of web service.Several separate web services coordinate and cooperate in a certain way in autonomous regions in order to provide a more powerful service,which is known as web service composition.Workflow management technology as a key technology of Computer Supported Cooperative Work,its main objective is to manage the courses of activities in various areas and to use various manpower or resources related to activities to achieve business process automation.This thesis works on key technologies related to web service composition and workflow management.Main topics in this thesis are discussed as follows:1) On the issue of service composition framework.Service composition is based on a service-oriented computing environment to achieve dynamic resource polymerization and services reuse and also constructing the application system of service composition is usually a more complex work.On the basis of analyzing the development process of service composition,this thesis induces universal supporting functions of web service composition systems and proposes a reference model on service compostion.This model devides service composition supporting platform into a number of relatively independent function modules so that the model can satisfy the demand of service composition on different stages.2) On the issue of service compostion analysis theory and methods based on business process.Service composition model is the high-level logic description on implementing service composition. Based on the business process modeling method is one of the important modeling methods of service composition.On the basis of workflow metamodel and WF-net reasonable definitions,this thesis presents workflow-oriented composite services,which can achieve implementation and binding of web services by using the the business logic and business rules between tasks defined in the workflow process model.3) On the issue of web sevice transaction and fault tolerance mechanism.According to traditional transaction handling mechanism,this thesis put forward to a transaction handling and fault tolerance framework applied in web service composition.In this framework,faults during the dynamic composition of web services can be detected timely and handled efficently with fault tolerance policies on web service.4) Based on the key technologies stated above,taking a national "11th Five-Year Plan" scientific and technological support plan named City Public Safety Emergency System which the author participated in as the background,this thesis focuses on implementation issues of composite service using in that system.By using those web service technologies,the system can package function modules to support various relevant government branchs in sudden emergency treatment.