The Implementation Of Component Variability Based On Design Pattern

The software reuse is regard as one of the effective ways to solve software crisis. Recently efforts show architecture-based, domain-specific reuse can yield great improvement. The successful reuse must be based on plenty of reusable software component, so the component development must be based on architecture and domain-specific. Domain engineering analyse lots of application systems and identify domain common and variable features, then abstract these features to form DSSA (Domain Specific Software Architecture). Reusable components are identified, developed and organized based on DSSA. Domain commonness is implemented by system architecture; domain variability is implemented by component. Component must treat with variability. So the implementation is the key work of the component development. There are some implementation approaches but they can well solve variability. This paper discusses the application of design pattern to implement component variability.Design pattern describes the solution to extensive software design by using object-oriented fundamental conception and mechanism, gives the reusable resolution approach. Design pattern provides the resolution to some variability in software design; it can be used to implement component variability. Based on the analysis of some approaches of component variability, this paper discusses the variability implementation approach by using design pattern. Firstly, from the point of domain variable feature the paper classifies the component variability into six types. Secondly, the paper uses the design pattern to implement each component variability type. Finally, the commercial POS domain is be analysed, the variability is classified, and using provided approach to implement the POS domain variability.