Research On WebGIS Service Aggregation Model Based On Workflow

With the widespread application of spatial information in various fields, as well as the development of network technology, it promotes the GIS development from closed, close coupling Component GIS to the open, loose coupling Service GIS, and Service GIS has become a new development direction of Geographic Information system. Therefore, Geo-Spatial Information Service (GWS) with uniform standard and normal interface has become the research emphasis of GIS vendors. However, with mature of the GWS, how to dynamically integrate the existent Web services to form a newly complex service is a popular research area, so that it can meet the requirement of different users.In this paper, some key technologies are researched in-depth, such as WebGIS, Web Service, SOA, workflow and other related technologies, Geo-Spatial Information Service group and Geo-Spatial Information Service chains are built. It sovles the problem about reuse and integration of GWS. A GWS dynamic aggregation meta-model base on workflow is presented, this model can adapt to the dynamic change of GWS effectively.Firstly, the concept system and the configuration services technology and standards for the level of structure of the WebGIS are researched, and GWS granularity of division is analyzed, and then the Geo-Spatial Information Service groups and service chains are built, a WebGIS framework based on SOA is implemented.Secondly, based on the characteristic of GWS and dynamic Services composition, the service dynamic aggregation meta-model is proposed, which can adapt to the dynamic characteristics of GWS for introduction of the concept of service group. Meanwhile, according to the meta-model, the implementation mechanism of dynamic aggregation of GWS is given, defining the content of research and hierarchical relationship of GWS. And based on the results of Workflow Management Coalition research, this paper puts forward Dynamic Service Composition Reference Model. Finally, using the workflow development platform WF-NET of Microsoft, the core functions of workflow management system are implemented, which builds the framework for the development of dynamic services composition system and the development of dynamic services composition application. The service aggregation model that proposed has been applied primarily at Oilfield Information Visualization. Therefore, the research of this subject is theoretical significance and application value.