Exploiting Roles and Responsibilities to Generate Code in a Distributed Design-Pattern-Based Programming System

The implementation of a design pattern can be viewed as a process of selecting classes to play the roles needed by the pattern. To ensure that a class can play a role, each role has a set of responsibilities associated with it. When all responsibilities are satisfied, the pattern implementation is complete. Normally a programmer must write code for the responsibilities. However, the implementation of responsibilities can often be derived from information in the application or from user input, and then automatically generated. This paper describes a new approach that uses roles and responsibilities to generate code for an almost-complete application architecture in a pattern-based framework, leaving only application-specific code for the developer. We demonstrate this approach using RMA, an Eclipse plugin for writing Java 2 Enterprise Edition (J2EE) applications based on an existing J2EE framework.