Applying and Combining Three Different Aspect Mining Techniques

Understanding a software system at source-code level requires understanding the different concerns that it addresses, which in turn requires a way to identify these concerns in the source code. Whereas some concerns are explicitly represented by program entities (like classes, methods and variables) and thus are easy to identify, crosscutting concerns are not captured by a single program entity but are scattered over many program entities and are tangled with the other concerns. Because of their crosscutting nature, such crosscutting concerns are difficult to identify, and reduce the understandability of the system as a whole. In this paper, we report on a combined experiment in which we try to identify crosscutting concerns in the JHotDraw framework automatically. We first apply three independently developed aspect mining techniques to JHotDraw and evaluate and compare their results. Based on this analysis, we present three interesting combinations of these three techniques, and show how these combinations provide a more complete coverage of the detected concerns as compared to the original techniques individually. Our results are a first step towards improving the understandability of a system that contains crosscutting concerns, and can be used as a basis for refactoring the identified crosscutting concerns into aspects.Comment: 28 page

An Aspect Refactoring Tool for The Observer Pattern

Current integrated development environments such as Eclipse provide strong support for object- oriented automatic refactorings; however, the same cannot be said about aspect-oriented refactor- ings. Refactoring of design patterns is one area where aspect refactoring automation remains to be explored in depth and few current tools are available to support it. To support aspect refactoring tools we present the AJRefactor plug-in, a semi-automatic refactoring tool for the observer pattern, a widely-used solution in the design of object-oriented programs. Aspect refactoring of the observer pattern allows aspects to capture pattern-specific code into a more modularized unit, and local- izes the code of participating classes. After applying AJRefactor on two Java projects JHotDraw and Prevayler, the results showed that AJRefactor was able to refactor 75% of the total observer instances found in both projects. Also, the refactoring enhanced the modularity and loosens the coupling of the pattern classes. Finally, the results showed a significant time savings and a small reduction in code size when refactoring with AJRefactor

ABSTRACT An Approach to Aspect Refactoring Based on Crosscutting Concern Types

We argue for the importance of organizing generic crosscutting concerns by distinctive properties and describing them as types. A type’s properties consist of a general intent, an implementation idiom criteria, and one (desired) aspect language mechanism to address the concerns within the specific type. We argue the usefulness of this approach for aspect refactoring, and in the areas of concern identification and aspect languages development. 1