基于构件的软件框架与角色扩展形态研究

Component-Based Software Frameworks and Role Extension Form

框架是实现大粒度软件复用的有效途径,面向对象框架可以通过实例化扩展实现具体的应用系统,但是,研究和实践表明,面向对象框架存在着一些问题,采用基于构件的框架(CBSF),通过用构件替代框架内部相互协作的类,以增大框架构成成分的粒度;同时利用构件的接口调用和组装实现框架扩展机制。主要探讨了角色扩展形态,角色是将要被进一步实例化的特殊构件,可分为抽象构件和模板,针对不同变化性类型,提出可以利用体系结构模式、设计模式或参数化这3种方式设计CBSF角色扩展,进而讨论了基于角色扩展形态的应用构件组装。

Framework is an important approach to large-grained software reuse. Object-Oriented frameworks are widely used through instantiation, but some shortcomings of object-oriented framework were mentioned during related researches and practices. Component-Based software framework (CBSF), which belongs to black-box framework, is adopted to solve these problems. In CBSF, component is chosen to substitute for collaborated class to increase the granularity of framework's element, and hot spot is implemented by component interface calling and components composition. Role extension form of CBSF is discussed, in which role is a special component that need to be instantiated, and can be categorized into abstract component and template. During the CBSF develop process, architecture patterns, design patterns and parameterization approaches are helpful to design role extension for different domain variability types. Some issues on composing application components based on the role extension form are also discussed.