基于RIA技术的WebGIS研究

Research of WebGIS Based upon RIA

该文分析了目前WebGIS所存在的问题,同时介绍了RIA的有关情况,并据此提出了基于RIA构建WebGIS的思路。在分析这种方案理论可行性的基础上,着重介绍了RIA环境下地理信息组织、存储以及缓存等关键技术问题,同时也给出了RIA构建WebGIS的体系结构方案,并对客户端、服务器端以及协议方面作了详细探讨,通过系统的开发,对下一步工作,如语义挖掘、安全问题等作了分析,认为RIA在地理空间数据的发布和共享中将发挥越来越大的作用。

Geographical Information Systems （GIS） are characterised by the ability to integrate geospatial data from a wide variety of sources. World Wide Web Geographical Information System （WebGIS） is the combination of Internet/Web technologies and Geographical Information System, it makes the Web publishing and sharing of geospatial information in the whole world possible and has exerted great influence on the national economic development and our everyday life. In the application of WebGIS, how to transfer efficiently the geospatial information, such as the user＇s spatial query submits and the result data from GIS database, through the network is a key factor to determine the capability of the system. This paper firstly analyses the problem existed in WebGIS, and then introduces the Rich Internet Applications, in short RIA, which is a brand-new Web application solution. Considering the trait of RIA, the thought for constructing WebGIS based on RIA is presented, and three key techniques adopted in RIA based WebGIS are summarized and analyzed. After that, this paper describes the framework of WebGIS based on RIA, consisting of five layers： client layer, presentation layer, business layer, integration layer and resource layer. In the design, the realization of client, server and protocol are discussed in detail. Finally, the thought given in this paper is proved feasible and effective with an experimental system, in addition, some future work in WebGIS based on RIA, such as security, interoperability are indicated and simply explored. The authors believe that with more research on WebGIS based on RIA, RIA will play greater role in publishing geospatial information, furthermore, the geospatial information web sharing will become easier.