Aspect oriented implementation of design patterns using metadata

Computer programming paradigms aim to provide better separation of concerns. Aspect oriented programming extends object oriented programming by managing crosscutting concerns using aspects. Two of the most important critics of aspect oriented programming are the “tyranny of the dominant signature” and lack of visibility of program's flow. Metadata, in form of Java annotations, is a solution to both problems. Design patterns are assumed as the general solutions for Object-Oriented matters. They assist in software complexity management and serve as a bridge among software designers as well. These properties have led the patterns to be introduced as a choice in order to prove new technologies. Successful implementations share a generic solution: the usage of annotation to configure and mark the participants, while the pattern's code is encapsulated in aspects. This loses the coupling between aspects and type signatures and between the code base and a specific AOP framework. Also, it increases the developer's awareness of the program's flow. In the present article, aspect oriented programming and design patterns are introduced and also taking the benefit of annotation equipment in java language is proposed as a solution to reduce tight coupling and increase program flow observation rate for aspect oriented programming. Keywords: aspect oriented programming, design patterns, object oriented programming, metadata.