Aop2007
- 1. Guided By: Prof. Manoj Chaudary Presented By:- Tuhin Das VI SEM CSE Smt.Bhagwati Chaturvedi College of Engineering, Nagpur “ EXPRESSION” - THE PAPER PRESENTATION
- 2. CONTENTS INTRODUCTION ABOUT OOP ASPECT ASPECTS & CLASSES KEY CONCEPTS EXAMPLE OF ASPECTS CROSS-CUT COMPONENTS THE ROLE OF ASPECTS IN SOFTWARE DESIGN ASPECTJ ASPECTJ EXAMPLE CONCLUSION REFERENCES
- 3. INTRODUCTION A new programming technique called aspect-oriented programming (AOP): makes it possible to clearly express those programs that OOP fail to support enables the modularization of cross-cutting concerns by supporting a new unit of s/w modularity aspects that provide encapsulation for crosscutting concerns
- 4. ASPECT An ASPECT is defined very much like a class and can have methods, field, advice initializers named pointcuts The current working definition : modular units that cross-cut the structure of other modular units units that is defined in terms of partial information from other units exist in both design and implementation
- 5. ASPECTS & CLASSES Similarities with classes: have type can extend classes and other aspects can be abstract or concrete can have fields, methods, and types as members Differences with classes: can additionally include as members pointcuts (picks out join points), advice (code that executes at each join point ) do not have constructor or finalizer and they cannot be created with the new operator privileged aspects can access private members of other types
- 6. KEY CONCEPTS Cross-cutting: Crosscutting is how to characterize a concern than spans multiple units of OO modularity. cross-cutting is respnsible for tangling in the code. Pointcut: This is the term given to the point of execution in the application at which cross-cutting concern needs to be applied. Join Points: Well defined points in code that can be identified.
- 7. EXAMPLE OF ASPECTS CROSS-CUT COMPONENTS We wanted to implement a distributed digital library that stores documents in many forms and provides a wide range of operations on those documents APPLICATION COMPONENTS ASPECTS digital database, minimizing network traffic, Library printers, synchronization constraints, services failure handling
- 8. EXAMPLES OF HOW ASPECTS CROSS-CUT COMPONENTS There are several aspects of concerns, including:
- 9. THE ROLE OF ASPECTS IN SOFTWARE DESIGN AOP aims at providing better means of addressing the well-known problem of separation of concerns. Three basic approaches to addressing the process of separation of concerns:
- 10. JOINT POINT MODEL The advice-related component of an aspect-oriented language defines a join point model (JPM). A JPM defines three things: JOIN POINTS POINTCUTS ADVICE
- 11. AspectJ AspectJ is: a general-purpose AO extension to Java Java platform compatible easy to learn and use freely available under an Open Source license AspectJ enables the modular implementation of a wide range of crosscutting concerns
- 12. AspectJ When written as an aspect the structure of a crosscutting concern is explicit and easy to reason about Aspects are modular AspectJ enables: name-based crosscutting (tend to affect a small number of other classes) property-based crosscutting (range from small to large scale) The goals of the AspectJ project are to make AOP technology available to a wide range of programmers, to build and support an AspectJ user community
- 13. AspectJ EXAMPLE An example is tracing aspect that prints messages before certain display operation The overall effect of this aspect is to print a descriptive message whenever the traced methods are called
- 14. AspectJ EXAMPLE Aspect SimpleTracing { pointcut traced() : call (void Display.update () ) ||call (void Display.repaint (..) ); before() : traced () { println(“Entering:” + thisJoinPoint); } void println (String str) { <write to appropriate stream> } } Traced identifies calls to several key methods on Display Before advice on this pointcut uses a helper method of the aspect to print a message Advice uses the thisJoinPoint special variable to an object that describes the current join point
- 15. CONCLUSION In the coming years Aspect Oriented Programming will replace all the programming like POP, OOP, etc. and it is being implemented in large scale in upcoming IT industries. Languages C/C++,.NETFramework languages (C# / VB.NET) Delpi, Java, etc have implemented AOP, within the language, or as an external library.
- 16. REFERENCES web site: http://aosd.net/ http://aspectj.org/ http://www.ccs.neu.edu/home/lieber/connection-to-aop.html
- 17. ANY QUESTIONS ??