A Framework Based on Design Patterns for Providing Persistence in Object-Oriented Programming Languages

This paper describes an approach to providing object persistence in object-oriented programming languages without modifying the run-time system or the language itself. By successively applying design patterns such as the Serializer, Factory Method, and Strategy patterns we develop an object-oriented framework for providing object persistence. The advantages of object-orientation are highlighted: structured classification through class-hierarchies, extensibility and promotion of reuse. The framework clearly separates persistence control from storage control. A hierarchy of different storage types, useful in different application domains, is introduced. The framework does not rely on any kind of special programming language features. It only uses basic object-oriented programming techniques, and is therefore implementable in any object-oriented programming language. An experimental implementation in Ada 95 is presented.