Designing and implementing software systems using user-defined design patterns

Abstract

Software design patterns are the design-level solutions for the commonly occurring problems in software development. Design patterns are applied in many industries where problems repeat with slight changes, and applying the same solution that is proven to be quality reduces the development time and maximises the software re-use. DesPat is a modeling toolset that offers a modeling notation set based on UML’s class diagram for the users to design their software systems using the well-known 6 design patterns proposed by Gamma et al. (abstract factory, singleton, composite, observer, visitor, and facade). DesPat also supports the combinations of different pattern models for any software system, analysis of the pattern-centric models, and their automated generation into Java skeleton code. In this paper, we extend DesPat with a new toolset that enables users to define their own patterns. A pattern is defined with the types of components, component interfaces, and relationships (i.e., generalisation, dependency, realisation, and composition). Any pattern definitions can then be imported into the DesPat modeling toolset, through which one may specify software design models in accordance with the pattern definitions, check the models against the pattern rules, and transform their models in Java. We illustrate our extension with the gas station case-study.