A 3-layer abstraction model to support Rapid Application Development

摘要

Rapid Application Development (RAD) tools minimize the effort of application programming by introducing systematic methodologies and user-friendly graphical interfaces. The ultimate goal of RAD is to reduce the work and the amount of technical knowledge required in developing an application program. In conventional software development methodologies, application programs are heavily dependent on the database schema. Indeed, the schema definition is exposed to the application codes. With object-oriented (OO) programming, an abstract layer is introduced to shield the data schema definition from the application codes, thus avoiding major rewrite during schema changes. However, the burden of having to design a database schema for every application cannot be avoided. This is an issue to achieve the goal of RAD because schema design is a fairly technically oriented task which requires specialized skills. Even worse, OO modeling lacks the ability to capture context-riched association relationships between the various objects. As a result, programmers need to capture such knowledge either in the database or in their programming code. This complicates the programming logic and makes it very difficult for the RAD tool to generate code beyond simple object In this paper, we introduce a 3-layer abstraction model to support RAD. This model is developed on an eBusiness Application Services Architecture called Organization Modeling and Management (OMM). OMM is composed of an Unified Information Model and a context-riched relationship model called Virtual Link. A tool named OMM/FastPath enables developers to automatically generate a data schema, capture context-riched association rules and generate codes on both the persistent class layer and the graphical presentation layer. With OMM/FastPath, a business user can create a J2EE web application without writing a single line of code.