Research Of WebGIS Based On J2EE And GML

WebGIS now is one of the primary research directions in geographic information system. Using WebGIS technologies can bring GIS to "socialization", and WebGIS is also one of the key platforms of the "Digital Earth" construction. There are many solutions for WebGIS, but the already existing "dark model" solutions do not meet the needs of new development more and more with the growth of demands in WebGIS, mainly because of the existing WebGIS have difficulties in geospatial data sharing and interoperability as well as can not adapt to the internet environment. Thus restrict the course of GIS socialization and block the development of "Digital Earth". Based on Open GIS Consortium's open GIS criterion and combined the development of computer technologies, this paper studies the WebGIS developing model deeply, then brings forward a new developing model and puts it into practice.The main work are as follows:1) Analyzes current situation and points out the challenges faced in WebGIS's development. Combined open GIS criterion and demands of web application then presents the design aim and development principle. Then based on the principle brings out solutions.2) Analyzes the advantages of GML in geospatial data sharing and interoperability, makes out a transitional solution based on the original "dark model";3) Goes deeply into the using of distributed computing technologies in WebGIS, discusses the advantages of developing WebGIS based on J2EE platform. Then gives a WebGIS browser/server distributed computing policy based on GML and step by step serving model;4) Use GML and web application server technology, designs a WebGIS system structure based on the J2EE multilayer network structure. The structure is a distributed structure according with the open GIS criterion in theory.5) Develope a WebGIS system based on the structure discussed above in practice. The paper also discusses some key problems while implementing.