An Extensible Class Library for Geographic Applications

The annual bill for software is rising sharply. Therefore, the code reusability is mandatory. At present the object-oriented programming paradigm seems to be one of the best solution to this problem; in fact, it allows the creation of "blank" applications that can be easily expanded into real ones. The aim of this paper is to design a class library tailored for geographic applications, as well as to substantiate the effectiveness of the object-oriented programming as a means to retrieve information from a large geographic database. In this paper, we do not provide a working implementation of the class library, but one that can be used as a reference for implementing it in one of the existing object-oriented languages. This choice is motivated by the need of collecting in one language all the features necessary to develop geographic applications effectively (e.g., availability of powerful "standard" classes, run-time support for data persistence both at the class and instance level, type checking, and so on), as well as to achieve a high code readability.