Research On RIA Based Components WebGIS Presentation Tier Technology

RIA (Rich Internet Applications) is a kind of Web technology. It brings Internet rich user experience. As the implement of RIA, Ajax changes Internet application model. It starts the Web 2.0 era. RIA has become one of the current hotspots of Web technologies. RIA impacts the application and systems which are based on Web so much.WebGIS is a kind of GIS which is based on Web. With the development of Web technology, WebGIS contains more and more functions. But the software becomes more complex. To solve the problem of WebGIS software reusing, the component technology has been introduced to WebGIS. It is called'Component WebGIS'. But in Web 2.0 era, users ask for more interactive applications. The'Component WebGIS'can't satisfy the users.This dissertation researched structure of'Component WebGIS'and also the RIA technology. And then it introduced the RIA technology to'Component WebGIS'representation tier. The main work and achievements of this dissertation are listed as following:1) A RIA-based'Component WebGIS'framework is proposed. This dissertation studied the RIA technology and improved the'Component WebGIS'five layers structure. The components which implement the basic GIS function are integrated to the representation tier. As the support of RIA, the users can execute map related command rapidly through the local components. The users can even do that off-line. The representation tier components are separated from font pages according to MVC pattern. It improves the reusability of representation tier components.2) This dissertation studied and implemented WebGIS representation tier components. This dissertation studied the GIS basic model and algorithm in representation tier components. These are the base of implementing GIS functions in representation tier. The representation tier components are designed according to Design Patterns.3) The strategy of the security of the representation tier data is proposed. Because RIA transmit the data by file based XML standard. And GIS data is high secret sometimes. So in the representation tier components design, the data security must be considered. This dissertation proposed a method that adds error to representation tier data to avoid data revealed.4) This dissertation introduced the search engine technology to RIA based components WebGIS. As RIA transmit data in XML format, spatial data could be found by search engine. This dissertation studied how to found spatial data by search engine.Through practicing in the project"Miyun Government Geographic Spatial Database Sharing Service Platform", this dissertation validates the feasibility of the RIA based Component WebGIS framework。...