Research On WEBGIS Development Technology Based-on J2EE MVC OpenSource Frameworks

The rapid development of GIS technology has brought significant innovation to the electronization, visualization and networking of geographic information. Meanwhile, the fast growth of Internet technology has brought greater opportunities to GIS, which causes WebGIS to come into being. Now, WebGIS develops deeply and broadly in theory, and has penetrated into all areas of life in application.Continuous development of WebGIS comes with users'higher expectations and demands. WebGIS develops towards lower user requirements, faster running, more practical and stable. On the other hand, more efficient implementation methods and technologies for WebGIS are in urgent needs. Currently, there are many WebGIS implementation technologies. Among them the one based on J2EE platform combines the advantages of the server and client implementations, providing more comprehensive support for the development of WebGIS. J2EE platform is characterized by extensive technology, and provides supports for frameworks designing, which makes the design and implementation of WebGIS more simple and convenient.Three lightweight open-source frameworks (Struts, Spring, Hibernate) of J2EE MVC are chosen to develop WebGIS in this thesis, and the MapGIS-IMS of Zhongdi Software Company is used as a secondary development platform, which offers a feasible solution for rapid development of more comprehensive and robust WebGIS. The main implementation methods are as follows:Struts framework is adopted to separate presentation layer and the application layer, which makes system structure more clearly. Hibernate framework provides persistence for data. Spring framework combines the above-mentioned two frameworks, and manages them and their business logic. The development technology of WebGIS based on J2EE MVC open source frameworks enables the developed WebGIS with these advantages:clear hierarchy, good scalability, good portability and platform independence.The shortest path problem as the key technology of WebGIS, is also studied. Based on the analysis of the classical shortest path algorithm, the optimized A* algorithm is adopted to solve shortest path problems, which achieves an improvement in time and space complexity. Finally, an example of WebGIS system is presented which is implemented by MAPGIS-IMS using a map of Wuhan with core road networks, and guided by the WebGIS development technology adopting J2EE MVC open source frameworks with the optimized A* algorithm.