设计模式和泛型技术在系统重构中的应用研究

重构是在不改变代码外在行为的前提下,对代码做出修改,以改进程序内部结构的过程.设计模式是对被用来在特定场景下解决一般设计问题的类和相互通信的对象的描述.泛型编程专注于将型别抽象化,形成功能需求方面的一个精细集合,并利用这些需求来实现算法.以一个应用系统的数据采集子系统的系统重构为例,将设计模式应用于系统重构中设计阶段,将泛型技术应用于系统重构实现阶段;讨论设计模式技术和泛型技术的结合对系统重构的作用与意义.     

A Knowledge-Based Software Engineering Environment for reusable software requirements and architectures

This paper describes a prototype Knowledge-Based Software Engineering Environment used to demonstrate the concepts of reuse of software requirements and software architectures. The prototype environment, which is application-domain independent, is used to support the development of domain models and to generate target system specifications from them. The prototype environment consists of an integrated set of commercial-off-the-shelf software tools and custom developed software tools.The concept of reuse is prevalent at several levels of the domain modeling method and prototype environment. The environment itself is domain-independent thereby supporting the specification of diverse application domain models. The domain modeling method specifies a family of systems rather than a single system; features characterize the variations in functional requirements supported by the family and individual family members are specified by the features they are to support. The knowledge-based approach to target system generation provides the rules for generating target system specifications from the domain model; target system specifications, themselves, may be stored in an object repository for subsequent retrieval and reuse.     

Distributed synthesis for well-connected architectures

We study the synthesis problem for external linear or branching specifications and distributed, synchronous architectures with arbitrary delays on processes. External means that the specification only relates input and output variables. We introduce the subclass of uniformly well-connected (UWC) architectures for which there exists a routing allowing each output process to get the values of all inputs it is connected to, as soon as possible. We prove that the distributed synthesis problem is decidable on UWC architectures if and only if the output variables are totally ordered by their knowledge of input variables. We also show that if we extend this class by letting the routing depend on the output process, then the previous decidability result fails. Finally, we provide a natural restriction on specifications under which the whole class of UWC architectures is decidable.     

对复用构件库体系结构的几点研究

复用构件库是软件复用的重要的技术支撑之一 .但由于目前的构件库体系结构主要是基于静态管理的数据仓储结构或层次结构 ,忽视了构件作为其复用单元本身的变化发展特征 ,所以并不能为软件开发提供真正意义上的面向复用的服务 .本文结合构件的复用性能的有关度量模型 ,提出了一种新型的层次型体系结构 ,从结构机制上提高了构件库的复用性能 ,有利于软件复用的实践与发展     

基于.Net的可复用软件开发框架的设计与实现

随着信息化技术的发展,数据库系统运用越来越广泛。在众多的数据库系统中,存在一些相同或者相似的功能模块,例如：用户登陆验证、系统用户管理、用户权限管理等。在实际的应用系统开发过程中,这些模块被重复开发,浪费了大量的人力、物力,并且会影响系统的开发进度。针对这种情况,文中提出了一个基于.Net的可复用软件开发框架WebFrameWork,对数据库系统开发过程中的一些常用功能模块进行集成,从而提高数据库系统的开发效率;并且详细阐述了WebFrameWork的设计方法;最后通过应用实例来说明WebFrameWork的使用方法。通过多个应用系统开发证明,该框架能够加快应用目标系统的开发速度,提高软件质量,节约成本,并且在稳定性和效率上能够满足实际需要。     

面向对象可复用软件设计思想分析

软件复用技术是有效利用已有的软件资源，提高软件开发效率，降低开发成本的技术．但是如何才能设计出一个可以复用的软件，这是我们大家都很关心的问题，Erich Gamma博士在这方面进行了有益的尝试，他的研究方法是总结前人在面向对象软件开发过程中所积累的经验，即模式，但是模式是如何总结出来的，在总结模式时，或者说在设计可复用的软件时应该如何思考问题，这比总结模式本身更重要．本文主要从软件复用的关键——隔离变化入手，深入探讨和分析了面向对象的软件系统构造过程中可能发生变化的点，并给出了屏蔽这些变化点的方法，并提出了一个设计面向对象可复用软件的新的可操作的思路、     

Software architectures to integrate workflow engines in science gateways

Science gateways often rely on workflow engines to execute applications on distributed infrastructures. We investigate six software architectures commonly used to integrate workflow engines into science gateways. In tight integration, the workflow engine shares software components with the science gateway. In service invocation, the engine is isolated and invoked through a specific software interface. In task encapsulation, the engine is wrapped as a computing task executed on the infrastructure. In the pool model, the engine is bundled in an agent that connects to a central pool to fetch and execute workflows. In nested workflows, the engine is integrated as a child process of another engine. In workflow conversion, the engine is integrated through workflow language conversion. We describe and evaluate these architectures with metrics for assessment of integration complexity, robustness, extensibility, scalability and functionality. Tight integration and task encapsulation are the easiest to integrate and the most robust. Extensibility is equivalent in most architectures. The pool model is the most scalable one and meta-workflows are only available in nested workflows and workflow conversion. These results provide insights for science gateway architects and developers.     

Failure-free coordinators synthesis for component-based architectures

One of the main problems in component assembly is how to establish properties on the assembly code by only assuming a limited knowledge of the single component properties. Our answer to this problem is an architectural approach in which the software architecture imposed on the assembly prevents black-box integration anomalies. The basic idea is to build applications by assuming a “coordinator-based” architectural style. We, then, operate on the coordinating part of the system architecture to obtain an equivalent version of the system which is failure-free. A failure-free system is a deadlock-free one and it does not violate any specified coordination policy. A coordination policy models those interactions of components that are actually needed for the overall purpose of the system. We illustrate our approach by means of an explanatory example and validate it on an industrial case study that concerns the development of systems for safeguarding, fruiting, and supporting the Cultural Heritage.     

可重用软件模式

软件重用是软件界追求的目标,人们正在努力将基于框架、体系结构和需求的重用变为现实,但是在具体实现技术上还不成熟。为了促进软件的重用,软件专家引入了结构化、可重用的软件模式来捕捉并描述软件业多年来成熟的软件知识和经验。该文首先阐述了软件模式的发展过程;然后介绍了软件模式的几个重要分支———设计模式、反模式和分析模式,并根据它们的特点进行了比较;最后指明了可重用软件模式的未来发展方向,并提出了以可重用软件模式为中心的领域工程方法。该工作强调了可重用软件模式在提高软件开发效率和质量上的作用,对提高国内软件重用水平具有重要意义。     

基于同态的软件重用技术的研究

针对一类现有软件重用方法不便于解决的重用问题，用代数中同态的方法从理论上对其进行了刻画和解决．经过分析指出，这种技术有助于提高编程效率，同时在一定条件下可以辅助不懂编程序的人得到所需要的程序。     

软件复用技术的探讨

软件复用是指利用现有的软件成分(资源)来构造新的软件系统。通过软件复用,在应用系统开发中可以充分地利用已有的开发成果,消除了包括分析、设计、编码、测试等在内的许多重复劳动,从而提高了软件开发的效率,同时,通过复用高质量的已有开发成果,避免了重新开发可能引入的错误,从而提高了软件的质量。该文将对软件复用技术的基本概念及关键技术进行全面的介绍。     

软件复用技术研究

软件复用是解决软件危机、提高软件生产效率和质量的现实可行的途径。该文着重软件复用的基本概念及软件复用的思想,研究了软件复用的过程及实现,分析和研究了软件复用所采用的软件构件技术中的关键技术。探讨了软件复用技术未来的发展趋势。     

SDH网管软件开发中的设计模式

设计模式描述了在软件开发过程中经常出现的问题及其解决方案,是软件复用的有效途径。文章详细地分析了设计摸式中的Factory模式、Observer模式、Bridge模式在SDH网管软件开发中的应用,证明了在SDH网管系统中运用设计模式能够有效地提高系统质量、优化系统结构。     

复用技术在软件工程领域中的应用

软件重复创建造成的巨大浪费,一直未被人们充分重视.构建软件复用库,实现复用驱动的软件开发过程是提高软件开发效率和质量的有效途径,分析复用驱动的软件开发过程,探讨了在软件工程领域实现软件复用的技术方法和软件复用能力评估.     

基于多层复用的工控软件设计

本文根据领域的不同层次，通过领域分析，提出了基于多层复用的工控软件设计方法。首先,我们研究了工业控制系统的领域特点，从工控软件要解决的功能和算法入手，建立工控软件的标准构件库；再结合特定应用领域。提炼抽象出面向某领域的应用功能构件库；然后在此基础上抽象出某一应用领域的构架库，并以轧钢领域为例作简要说明。最后给出了基于多层复用的工控软件设计过程。     

基于多层复用的工控软件设计

本文根据领域的不同层次,通过领域分析,提出了基于多层复用的工控软件设计方法。首先,我们研究了工业控制系统的领域特点,从工控软件要解决的功能和算法入手,建立工控软件的标准构件库;再结合特定应用领域,提炼抽象出面向某领域的应用功能构件库;然后在此基础上抽象出某一应用领域的构架库,并以轧钢领域为例作简要说明。最后给出了基于多层复用的工控软件设计过程。     

Component Specifications for Robotics Integration

Robotics researchers have been unable to capitalize easily on existing software components to speed up their development efforts and maximize their system's capabilities. A component-based approach for building the software for robotics systems can provide reuse and sharing abilities to the research community. The software engineering community has been studying reuse techniques for three decades. We present several results from those efforts that are applicable to the robotics software integration problem. We describe how to specify a software component so that a potential user may understand its capabilities and facilitate its application to his or her system. At the National Institute of Standards and Technology, we have developed a three-stage, component-specification approach. We illustrate this approach for a component that is relevant to robotics.     

基于特定域软件体系结构的软件复用

软件复用是在软件开发中避免重复劳动的有效方法。通过软件复用,可以提高软件开发的效率和质量。软件体系结构作为软件的蓝图,为人们宏观把握软件的复杂性和整体变化性提供了一条有效途径,被认为是支持软件开发和复用的重要手段之一。特定域软件体系结构定义了域的共同特性,由于域的特定性,从而使复用的可能性大大提高。本文从软件工程的角度,分析了基于特定域软件体系结构的软件复用的可行性。