基于RIA和SOA的分布式WebGIS研究

【作者】 刘磊；

【导师】 兰小机；

【作者基本信息】 江西理工大学 ， 地图学与地理信息系统， 2011， 硕士

【摘要】 WebGIS是Internet环境下的一种传输、存储、处理、分析、显示与应用地理空间信息的计算机系统,是WWW(World Wide Web)技术和GIS技术的有机结合。随着互联网影响的扩大和GIS在各行业中的广泛应用,人们已不满足目前基于HTML技术的WebGIS的表现效果和系统伸缩性,分布式WebGIS(DWebGIS,Distributed WebGIS)将数据查询、分析、存储等任务分布在不同的服务器上,具有更好的整体性能。RIA(Rich Internet Application,富网络应用)是新一代网络应用程序,具有良好的表现力与交互性,给WebGIS的发展带来了新的机遇,Silverlight平台是微软公司推出的非常有前途的RIA开发技术;SOA(Service-oriented architecture,面向服务的架构)是目前比较流行的计算机软件架构体系,Web服务的诸多特性使其成为实现SOA架构的最佳技术规范,REST风格的Web服务则因其简洁高效而越来越受到重视,众多地理信息服务公司纷纷推出了基于REST风格的地理空间Web服务。本文基于以上技术,以分布式WebGIS为研究对象,探讨RIA/Services结构体系的WebGIS开发方式,并以Silverlight和ArcGIS Server为平台阐述了实践方案,开发的实验系统提高了WebGIS的表现力与交互性,同时降低了开发的复杂性和产品周期,具有一定的理论和现实意义。本文主要作了如下研究:1)在比较研究主流RIA实现技术的基础上,重点研究了Silverlight平台的核心技术以及如何将Silverlight应用于WebGIS的算法和原理,研究了ESRI公司的ArcGIS Silverlight API,并对其在地图打印、加载Shapefile文件等五个方面的不足进行了扩展和完善。2)在比较研究分布式WebGIS实现框架的基础上,重点研究了如何使用Web服务技术实现基于SOA的分布式WebGIS系统,并从地理空间Web服务和业务数据Web服务两个方面进行了阐述,研究了ESRI公司发布的基于REST风格架构的ArcGIS REST API开发接口,对其工作原理进行了阐述。3)传统WebGIS构建方案存在表现力差、耦合度高、难维护等缺陷,本文在研究RIA技术和Web服务技术的基础上,提出了以RIA/Services架构体系开发分布式WebGIS系统的方案,详细研究了R/S架构的结构和开发步骤,并基于ArcGIS Server平台阐述了实践方案。4)在相关技术的研究基础上,本文使用Silverlight 4.0和ArcGIS Server 10.0做了系统开发实验,模块功能基本达到预期目标,系统用户端表现力和交互性好,服务端耦合度底、伸缩性高,验证了R/S结构体系在开发分布式WebGIS系统中的应用价值。更多还原

【Abstract】 WebGIS is the World Wide Web geographic information system that use of interactive web technology to extend and improve a geographic information system technology, which is a combination of Internet and GIS products. With the growing impact of the Internet and GIS technology being widely applied to various industries, it is no longer satisfied with the current WebGIS based on the performance of web technology and interactive effects, and the development of system scalability and simplicity is also a higher requirements. RIA (Rich Internet Application, Rich Internet Applications) is a new generation of web applications, with good interaction with the user experience, the application will bring revolutionary changes to the Internet, but also to the WebGIS has brought new development opportunities and silverlight is Microsoft launched a very promising development of RIA technology. REST is a new style of web services; it will prepare the server to share any information as a resource and an identifier for each resource to determine the client identifier to operate through the resources, access to resources. Based on these new technologies to WebGIS for the study is to explore how the Silverlight framework and REST style architecture applied to the WebGIS in force in improving the performance of WebGIS and interactivity while reducing development complexity, increasing system scalability, with certain theoretical and realistic significance.This paper made the following studies:1) Firstly, studied the latest release of ESRI’s ArcGIS RIA technologies-ArcGIS API for Silverlight, Silverlight platform to build on this technology in the animation effects, reaction speed, multimedia integration, the chart shows, many aspects such as transparency control than on HTML has a greater advantage of traditional WebGIS.2) Of the REST style of architecture and technology of ArcGIS REST API, REST is a way of publishing Web services, with a simple, easy to deploy, easy to maintain the characteristics of the next generation will be the main push of ArcGIS Server GIS services distributed.3) Focusing on the development of the ArcGIS API for Silverlight RIA client and to publish ArcGIS Server REST service as a way of server side WebGIS development proposed R/S-based WebGIS, analysis of the R/S structure compared to traditional C / S architecture and B / S architecture advantages. Silverlight and REST study shows that in the WebGIS have broad application prospects.4) Based on the study of relevant technologies, this article uses Silverlight 4.0 and ArcGIS Server 10.0 to do a test system development, basic functions to achieve the desired objectives of the module, the system performance of power and client interaction, good service, coupling the bottom end, high scalability To verify the R / S structure in the development of distributed WebGIS system value.更多还原