Applying Software Patterns in the Design of a Table Framework

This paper describes how software design patterns are applied to advantage in the design of a small application framework for building implementations of the Table Abstract Data Type (ADT). The framework consists of a group of Java interfaces that collaborate to define the structure and high-level interactions among components of the Table implementations. The key feature of the design is the separation of the Table’s key-based record access mechanisms from the physical storage mechanisms. The systematic application of the Layered Architecture, Interface, Bridge, and Proxy patterns lead to a design that is sufficiently flexible to support a wide range of client-defined records and keys, indexing structures, and storage media. The use of the Template Method, Strategy, and Decorator patterns also enables variant components to be easily plugged into the framework. The Evolving Frameworks patterns give guidance on how to modify the framework as more is learned about the family of applications. The conscious use of these software design patterns increases the understandability and consistency of the framework’s design.