Of Gml Map Component Of The Design And Realization

GML(Geography Markup Language) that defined by the Open GIS Consortium is one of geographic markup language based on the XML. It codes the information(the area,location content and so on) in the form of XML,and departs the content and the form.If we want to realize standardization and structure of the spatial geographic data,and the interoperation of the GIS,we should organize and represent the data through GML.GML as a storage and exchange of spatial information of the XML encoding format, has gradually been widely accepted and used. As GML itself doesn't have the capacity of demonstration,it is necessary to solve the problem of the visualization of the GML data through searching from the technical aspect.This paper introduces the OpenGIS specifications to build a unified description of GIS and spatial data integration platform, and from the perspective of problem-solving leads to the discussion of GML, as well as its main technical features and application of advantage to study the performance of its data capabilities and applications to expand capacity. On this basis, further explored the logic of GML data processing and elements of visual expression. GML-based OpenGIS specification is designed graphical display component has a certain significance. The main contents of the dissertation are as follows:1. The dissertation described in detail GML data model, mainly includes three core models: feature model, geometric model, topological model. The core of the GML data model and its modeling mechanism of the in-depth analysis, introduced to deal with GML document commonly used in two main programming interface.2. According to the structural characteristics of GML documents, using Document Object Model (DOM), for parsing GML was designed according to geographical elements of its class hierarchy of the logic processing solution to implement geospatial objects spatial data and non-spatial attribute data separation.3. The use of object-oriented design techniques and methods are based on a custom map component in the form of GML as a means of elements of spatial data visualization program, from the performance and interoperability of spatial data in terms of elements of GML spatial data visualization and the editors of the research and application, and construct a prototype system.In a word, this research work on the integration of GML spatial data sharing and storage management has very important significance.