基于XML-RPC的分布式地理信息系统计算模型

A Study on XML-RPC Based Distributed Computing Model of Internet GIS

分布式异构 GIS系统集成与互操作是 GIS应用发展的趋势和方向。本文在 WMS和 GML研究基础上 ,提出了一种基于 XML - RPC的分布式 GIS计算模型 ,设计了分布式 GIS应用操作与数据的 XML抽象与表达 ,并进行了原型系统的实现研究。

The integration and interoperation of distributed inhomogeneity GIS system is the direction of GIS development. Based on the research of WMS(Web Map Service),WFS(Web Feature Service) and GML, this paper presented a new XML-RPC based distributed computing model of internet-GIS. The Model is composed of three tiers, the diverse geo-processing or geo-processing-enabled client, the GIS distributed computing mid-ware and the geo-processing server. XML-RPC is used to carry out the communication between geo-processing client and geo-processing server by GIS distributed computing mid-ware. Login,Logout,GetCapability,GetMap,GetFtrInfo,GetSelFtrs,GetThemMap and GetStatMap are defined as the basic GIS computing command in XML. GML 2.0 is used to present the geo-spatial data and geo-processing result. The geo-processing sever may implement the XML-RPC interface directly, such as Web Map Server, or use a adapter to encapsulate the geo-processing service. The geo-processing client uses these basic commands and their combination to call the geo-processing service. The geo-processing sever executes geo-processing using its own geo-spatial data,application model and computing resources. Then the geo-processing client receives the geo-processing results as image stream and/or feature stream encoded in GML 2.0 and thus integrate the distributed inhomogeneity geo-processing server systems.