摘要
伴随着IT行业的快速发展,网络教育在中国快速地开展起来,网络教学平台的数量与日俱增,伴随而来的还有快速增长和不断变化的需求。不可避免会出现旧软件系统由于不能适应需求的增长和变化面临被废弃的处境。面向服务架构(SOA)为这样的难题提供了解决方案。SOA作为软件业一个主要的发展趋势,解决上述问题已经初见成效。因此如何将现有的系统改造成为基于SOA的系统就显得十分重要。
本文介绍了面向服务架构概念的由来、发展及前景,指出了研究的目的和意义。然后分析和比较了当前面向服务架构的流行的实现方法和相关技术;研究国内外成熟的面向服务架构的产品;分析和比较了国外先进远程教学系统的设计规范和模型;以笔者参与的由北京邮电大学网络教育研究所承担的“十五”国家科技攻关课题“基于国产基础软件的B/S架构多媒体系统”为依托,通过分析与研究,重新设计并细化了该系统的服务。最后作为应用实例,笔者采用了SOA主流实现技术——web service实现了该系统中的问题库同步服务。此外,单点登录(SSO)功能是实现SOA的必要条件,本文对单点登录的各种实现方式进行比较,最后提出了一种简化的SSO,并阐述实现过程。
Following the fast-stepping IT Industry, cyber education is accelerating its expansion. More and more on-line learning systems are built on ever growing and changing demand. But once an online system is built, it can hardly meet the new demand. Therefore, many old systems are facing the facts that they will be out of use. SOA (Service-Oriented Architecture) may provide a good solution for this awkward situatioin. SOA, regarded as a major trend in software industry, has achieved initial success. Thus it becomes very important that how to migrate old systems to the SOA-based application system.
This paper introduces the history and prospects of SOA, and points out the purpose and significance of the study. This paper will include the study of mature application of SOA and the technologies related and also analyse the relevant specification about the e-learning system. Base on the project of "B/S Multimedia Teaching System Based on homemade software" of "10th five-year"plan, this paper redesigned and subdivided service items for future service-oriented modification. Web Service, as the most popular implementation technology of SOA, will be applied to pack a service in the Multimedia Teaching System as an example to fulfill the SOA strategies. SSO (Single Sign-On), as an indispensable part of SOA, will be studied and discussed. Then this paper will come up with a simplified version of SSO and implementation details in the end.
引文
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