面向服务的分布式地学模型集成框架研究

A Service-Oriented Framework of Distributed Geographic Model Integration

通过对模型库、G IS与应用分析模型集成方式的探讨,结合未来以分布式资源共享为特征的系统构建模式,提出了面向服务的分布式地学模型集成框架。该框架通过将XML文档对象模型引入到模型定义中,统一了模型数据和功能的定义,基于COM技术实现了模型集成运行服务器和模型服务访问组件。模型服务器扩展了传统模型库的功能,为异构模型提供了集成和运行环境;服务访问组件实现了面向对象的服务访问接口,为应用系统开发提供了一致的集成模式。

System integration has been proposed as one of the characteristics which distinguish GIS from other information systems, but there are no appropriate methods to integrate with GIS and geography-model to perform flexible retrieval, development, and reuse mechanism. This paper makes an analysis on the modelbase system and the methodology of integration with GIS and geographic models, and proposes a service-oriented framework of distributed geography model integration. The goal of our research is to design a software framework, which can support distributed model construction, management and integration, with a concept of service and share. At first, we describe the model definition framework which defines model functions and data interfaces on the basis of the ideology of the document object model （ DOM ） , with more details of the flexible data definition mechanisms which can support dynamic data interchange and definition with XML. The framework can assist modeler to construct models for particular application domains and make the model features understood by GIS- developers more easily. Next, we describe the software structure with two components, the model server and the client, which are both based on the COM/DCOM technology： the model server, supporting RPC access, expands the function of traditional model base, provides the run-time supports and the integration environment into all kind of model programs, will facilitate the incorporation of legacy simulation models into the environment ; the client component, composed of a set of COM components with DOM, provides the uniform pattern for integrating models and GIS application with the object-oriented application programming interface. Thus, this framework provides a basis for distributed model construction and sharing not only on the combination of GIS and model program, but also on other SDSS projects.