Automatic verification of design patterns in Java

Design patterns are widely used by designers and developers for building complex systems in object-oriented programming languages such as Java. However, systems evolve over time, increasing the chance that the pattern in its original form will be broken.To verify that a design pattern has not been broken requires specifying the original intent of the design pattern. Whilst informal descriptions of design patterns exist, no formal specifications are available due to differences in implementations between programming languages.We present a pattern specification language, Spine, that allows patterns to be defined in terms of constraints on their implementation in Java. We also present some examples of patterns defined in Spine and show how they are processed using a proof engine called Hedgehog.The conclusion discusses the type of patterns that are amenable to defining in Spine, and highlights some repeated mini-patterns discovered in the formalisation of these design patterns.