Research On The Implementation Of WebGIS Based On Flex And ArcGIS Server

WebGIS namely World Wide Web Geographic Information System, is an outcome of applying internet technology to the GIS development, and efficient developing of expressive WebGIS applications has become the mainstream of the GIS application development. As the influence of Internet continues to expand and the application of GIS technology in industries becomes more extensive, people are no longer satisfied with the performance effect and interactivity of the WebGIS which is based on the traditional web technology, and put forward higher requests for both the system's flexibility and development simplicity. The emergence of a new generation web application named RIA (Rich Internet Application), with its good interactivity, expression and user experience has brought new development opportunities to WebGIS. Flex is currently the mainstream technology in developing RIA, and REST (Representational State Transfer) is a new way of web application design and development. The REST-style application programming interfaces of ArcGIS Server together with Flex have provided a practical and convenient approach for developing the new generation WebGIS application.Supported by Research on Monitoring and Prevention of Geofractures and Land Subsidence in Basin of Fenhe and Weihe River as a key work project in Survey on Land Resource, applying RIA and REST technologies, the research work in this paper discussed the integrating techniques and implementing methods about the new WebGIS development based on Flex framework and ArcGIS Server. This paper firstly expounded the Flex framework and ArcGIS Server system structure, and analyzed the specific method and technical details that using ArcGIS API for Flex to construct WebGIS applications; secondly, focusing on the key technical problems in the WebGIS development based on Flex, it carried out intensive studies and came up with the integrated solution to enterprise-level WebGIS; finally, it implemented the WebGIS application named Information Management System of Geofractures and Land Subsidence Hazards in Basin of Fenhe and Weihe River (hereinafter simply referred to as FWDD-GIS), thus verifying the advancement and the convenience of integration WebGIS development method. This research has made the following results and conclusions.1) Using RIA and REST technology, the paper designed and implemented the general development framework of WebGIS based on Flex and ArcGIS Server, which can serve as a reference for developing WebGIS applications of similar demands.2) Throungh in-depth study, it solved a series of key technical problems in developing WebGIS applications based on Flex and ArcGIS Server, such as developing user-defined client components or controls, client map data real-time update and management, extending client functions, as well as solving the safety-sand-box conflicts in Flex cause by cross-domain data access.3) Through the research on ArcGIS Server service parameters, it proposed concrete methods to optimize the application system's overall performance from the server-side.4) The research work preliminarily finished the design and the development of FWDD-GIS application system in Adobe Flex Builder 3 environment. The system is of high efficiency, strong interactive capability and rich expression, and has generally met the practical requirement. Besides, it has basic functions and common abilities such as management, statistics, display, query, analysis and so on. This practice reflected the superiority of WebGIS systems based on Flex.