Research And Implementation Of An Urban Service Information Retrieval System Based On Web-GIS

The RIA-based WebGIS technical framework,based on B/S architecture, which is easy to deploy and maintain,can bring a positive user experience like the application system based on C/S architecture.This method is a good solution to the traditional WebGIS development in the lack of user experience.After analyzing and studying a large number of existing research results, the author of this paper proposes to build a RIA-based WebGIS application model based on Flex framework, and implements a city service information retrieval system using this architecture model, and detailedly descripes the system architecture and related core technology.The author's research work and innovation can be summarized as follows:1) Proposed to integrate Flex and J2EE to build a WebGIS application solution suite to RIA, based on researching and analyzing the exsiting WebGIS solution2) Designed the spatial data model based on Geodatabase and established relevant database table structure3) Researched and implemented the communication link between Flex and J2EE server and GIS server. In the traditional J2EE-based WebGIS Flex applications, Flex only connected with J2EE server, which invoked services released by GIS server to do the GIS operation.This architecture is redundant. This paper proposes a clearly architecture in which the Flex client can make direct connection with the GIS server by ArcGIS API for Flex.4) This architecture uses the latest release of ArcGIS Server 9.3 platform as the GIS server, which applies the Geometry Service and many other new features. Attribute data server uses the JAVA-based J2EE architecture, which utilizes Hibernate's lazy loading and caching mechanism to reduce the frequency of the database read and improve the efficiency of the systemExperimental results show that the WebGIS solution raised by this paper has a wide range of practical value.