.j2ee/xml Distributed Webgis In Applied Research

Nowadays, GIS, centers on data, is a geographical information service. At the same time, because of the quick expanding of the field in GIS application, GIS has gradually infiltrated into every profession and department. Gathering material respectively and repeatedly for every department will leads to the waste of the system investment and resource. Consequently, sharing resource and data in every field has become the basic requirement, of which WebGIS can be browsed simultaneously. The used centralizing server mode in traditional meaning WebGIS can't meet the need of a large number of information transmissions and a great quantity user accessing simultaneously. In order to realize the geographical information resource in sharing and opening, the essential way in improving the system flexibility and enhancing the function of those existing WebGIS is setting up a geographical distributed and integrate logic and also including multi-database Servers, GIS application Servers and distributed WebGIS in Web Server. The developing trend in WebGIS is setting up a distributed WebGIS, which can support the releasing large data spatially, access various sources, different forms of spatial data and the deploy of multi-tier system architecture, and also use available resource greatly and meet the need of accessing for user effectively. Focused on the key word of "distributed", firstly, the thesis briefly introduces the concepts and development prospects of GIS and WebGIS, and comparing to the current WebGIS realization technique, I point out the using of distributed object technique can meet a favorable flexibility and expansibility for WebGIS and especially a good method in realizing distributed WebGIS. Then, it is important to describe the distributed WebGIS and its key issue-interoperability, and interoperability also is a currently significant studying task. At present, there are lots of methods in solving the interoperability problem. We think the "XML standard" and "distributed" methods are the feasible methods in solving the interoperability of WebGIS. I made a comparable detailed study on the ArcXML and J2EE, the traditional standards, in these two methods. Finally, based on the J2EE platform and ArcIMS releasing system, the thesis presents a developing experiment in using ArcXML and J2EE technique, which verified the feasibility of the upper theories.