摘要
SOA是一种面向服务的架构方法,与传统的面向对象和基于构件的软件开发方法相比,SOA具有服务共享、基于标准等特点。随着软件技术的发展,尤其是Web服务的出现,SOA架构技术正得到广泛的应用。
网络考试系统是一种常用的计算机教育应用系统,它可以合理利用考试资源、提高教学效率。目前国内的网络考试系统多是面向应用的,存在重复开发、资源共享性差等问题。
本文描述了如何采用面向服务的设计方法,实现一个松散耦合的网络考试系统。概括起来,论文的主要研究工作有:
1.网络考试系统需求分析
本文给出了基于网络的考试系统需求分析,并结合系统中“考务管理子系统”的具体应用,在遵循SOA架构和各层次模式的基础上对其进行了详细的分析和设计。同时,对其分析过程、用例建模、静态结构以及动态行为模型进行了具体说明。
2.基于SOA的网络考试系统的设计
结合基于SOA的网络考试系统的开发实例,本文提出了设计系统时可参照的划分结构层次的方法,并抽象出各层次设计实现时所应遵循的模式。提出了在服务层使用Web Service Interface以使较细粒度的Web服务只集中在应用程序内部;提出了在服务组件层中引入Session Facade作为会话门面。
3.系统实现的关键技术的研究
根据之前提出的系统需求和设计,本文讨论了基于SOA的网络考试系统实现过程中的一些关键技术。包括Session Facade的生成;使用JAX-RPC将EJB封装成Web服务;使用WSDL对Web服务进行规范化描述;使用BPEL4WS描述Web服务流程等。
SOA is a development method of Service-Oriented Architecture. Compared with the traditional development methods such as Object-Oriented programming and the technology based on the component, SOA has many advantages, such as services-sharing and standards-based, and so on. With the development of the software technology and the appearance of the Web Service, SOA will be applied more and more widely.
Internet based exam system is a popular CAE soft, which could take advantage of education resources reasonably and improve the teaching efficiency. Currently, all the design approaches used for the internet based exam system are Application -Oriented. Therefore, some problems exist such as repetition development or non-sharing resources.
The thesis described how to design and implement a loosely coupled internet based exam system using Service-Oriented Architecture. The mainly works of the thesis focus on the following aspects:
1. Requirement analysis of the internet based exam system using SOA
The thesis proposed the requirements of the internet based exam system. Combined with the application of the "exam affair management sub-system" in the internet based exam system, the thesis described its analysis and design Based on patterns of each hierarchy and structure of SOA. Meanwhile, it elaborated analysis process, use case modeling, static structure and dynamic action model of the system.
2. Design of the internet based exam system using SOA
Combining with the instance of the internet based exam system using SOA, The thesis proposed the method used to divide the structure hierarchies when a system is designed and described some design patterns used to implement the design. The thesis put forward a Web Service Interface, which is used in service layer, to integrate the Web services with the fine granularity into the inside of program. In addition, the thesis proposed that Session Facade should be used in the service component layer.
3. Research of the key technologies in the system's implementation
According to the analysis and design, the thesis discussed the key technologies of the implementation for the internet based exam system using SOA in detail. Such as the implementation process of a Session Facade, encapsulating EJB services into the Web services with JAX-RPC, describing the Web Services in standardization with WSDL and describing the Web Service business process with BPEL4WS.
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