WebGIS中可约束的实时协同编辑系统的研究与实现

发布时间：2018-04-19 09:34

本文选题：WebGIS + 协同编辑　；参考：《福州大学》2013年硕士论文

【摘要】：随着Internet的迅速发展,GIS网络化成为了GIS的发展趋势,WebGIS应运而生。面向WebGIS的协同编辑也成为了WebGIS快速发展以及编辑任务扩大化后的一个重要研究课题。然而由于WebGIS数据表现形式和数据渲染方式的独有特点,很多在其它领域成熟的协同设计方法,在WebGIS领域无法直接使用,甚至无法使用。因此研究如何借鉴已有的协同设计研究成果,使其能够解决WebGIS中协同编辑存在的问题,有其现实意义。在系统的体系结构方面,本文根据WebGIS中矢量地图的特点,以图层为粒度进行数据和任务的分配,将同一图层的数据交由同一图层服务器进行管理,然后采用一个中心服务器来协调各图层服务器。图层内部问题可以由图层服务器自主解决,图层之间的问题才交由中心服务器协调解决,加大了协同编辑的并发力度。采用编辑节点监控策略来监控节点状态,编辑节点允许动态的加入和退出,使得系统的适用性增强。系统运行时,合法操作实时进行广播,使得各节点可以第一时间同步到最新的编辑状态。在协同编辑并发控制策略方面,本文采用了基于并行操作矩阵的隐藏对象加锁机制。用户在操作时,根据并行操作矩阵来判断是否需要加锁。加锁时,对编辑对象隐藏加锁,用户在不知情的情况下,自动被系统加锁,避免了加锁粒度和加锁时机难以用户自主抉择的弊端。根据编辑往往存在条件限制的情况,本文引入了约束的概念。采用约束模型,在协同编辑的同时考虑约束,进行约束检测和面向约束的冲突消解。并设计了集成冲突消解流程,通过冲突检测、基于规则的消解、基于事例的消解、协商消解、仲裁的次序来逐步多策略地进行消解。在约束管理和消解上,都采用了层次结构,即先在图层服务器中处理,处理完成后,再提交给中心服务器处理。最后本文根据前文的分析和设计,实现了一个面向WebG IS的协同编辑系统,通过系统的实际运行来验证理论的可行性。
[Abstract]:With the rapid development of Internet, GIS network has become the developing trend of GIS.Collaborative editing for WebGIS has also become an important research topic after the rapid development of WebGIS and the expansion of editing tasks.However, due to the unique characteristics of WebGIS data representation and data rendering, many collaborative design methods, which are mature in other fields, can not be directly used or even used in the field of WebGIS.Therefore, it is of practical significance to study how to use the existing research results of collaborative design for reference so that it can solve the problems existing in collaborative editing in WebGIS.In the aspect of system architecture, according to the characteristics of vector map in WebGIS, this paper distributes the data and tasks with the grained layer, and manages the data of the same layer by the same layer server.Then a central server is used to coordinate each layer server.The internal problems of the layer can be solved by the layer server independently, and the problems between the layers can be solved by the central server, which increases the concurrency of collaborative editing.Editing node monitoring strategy is adopted to monitor node state, and editing node allows dynamic join and exit, which makes the system more applicable.When the system is running, the legitimate operation broadcasts in real time, so that the nodes can synchronize to the latest editing state at the first time.In the aspect of co-editing concurrency control strategy, the hidden object locking mechanism based on parallel operation matrix is adopted in this paper.During operation, the user determines whether a lock is needed according to the parallel operation matrix.When locking, the editing object is hidden and locked, and the user is automatically locked by the system without knowing it, thus avoiding the disadvantage of locking granularity and locking timing which is difficult for the user to choose independently.This paper introduces the concept of constraint according to the condition of editing.The constraint model is adopted, and constraints are taken into account in collaborative editing, constraint detection and Constraint-Oriented conflict resolution are carried out.The integrated conflict resolution process is designed, which is based on conflict detection, rule-based resolution, case-based resolution, negotiation resolution and arbitration order.In constraint management and deconstruction, the hierarchical structure is adopted, that is, processing in the layer server, after the processing is completed, then submitted to the central server for processing.Finally, based on the above analysis and design, a collaborative editing system for WebG is implemented, and the feasibility of the theory is verified by the actual operation of the system.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P208;TP393.09

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