Designing And Implementing WebGIS With MVC Design Pattern

WebGIS is the combination of GIS and Internet (WWW), It is not only an important means for geospatial information sharing in web, but also key technique for the establishment of the National Spatial Data Infrastructure and Digital Earth.MVC(Model-View-Control) is a design pattern proposed by Xerox PARC in 1980' s. It reduces the degree of coupling between the objects involved in maintaining and presenting data by separating the logic layers and view layers. It not only makes the system flexible to develop but also raises its reusable ability.In this dissertation, The author discussed the trend of GIS development, the concept of WebGIS, WebGIS characteristic, WebGIS implementing strategy and technology etc. Then by analyzing the problems existed in WebGIS, the author point out that traditional WebGIS is independent and isolated and there is no sufficient interoperability among different systems. All these problems hold back WebGIS development.To solve these problems, the author proposed a scheme: WebGIS based on Java technology and MVC design pattern. It has not only cross-platform and security characteristic of Java, but also loose and coupling characteristic of MVC architecture. This scheme can help us solve many problems existed in WebGIS.Finally the author develop a prototype system based on the above schema. It includes three parts: client, apply server and geographic information server. Through some tests with the prototype system, the theory correction and technique feasibility of the schema presented in the dissertation were proved.