Contracted Persistent Object Programming

Enterprise applications, that is large and long-lived applications, require persistence. Conventional approaches to persistence suffer from various deficiencies since they pass a considerable amount of the persistence workload on the programmer. Programmers have to transfer data to and from storage devices and have to provide mappings from the programming data structures to the storage device data structures. Thus, programmers are distracted from modeling the application logic. The invention of orthogonal persistence has provided substantial remedy: the automation of persistence-related operations lets programmers focus on application logic and facilitates reuse. In this paper we introduce contracted persistent object programming, a new approach to persistent programming, that is based on orthogonal persistence, but constrained to the object-oriented case. Contracted persistent object programming further extends orthogonal persistence by Design by Contract and the uniform handling of transient and persistent objects.