Aspect-oriented Programming Approach Research Articles

Applying Aspect Oriented Programming in Distributed Application Engineering

Aspect-oriented programming is an emerging programming paradigm that stretches during the development phases in different domains. Many researchers have focused on the use of this paradigm in web service composition in different research axis. However, none of them use together aspect-oriented programming and design by contract to deal with the adaptation of the parameters in the web service composition process. This paper proposes a web service composition algorithm based on the planning graph using both Aspect-oriented programming and design by contract concept. The aspect-oriented Programming approach provides explicit support for separation of crosscutting concerns in web services composition whereas the design by contract approach allows the processing of parameters execution in pre-condition and post-condition mode by using contracts in order to ensure correct service execution with adaptation to external parameters without touching in properties which can be dealt with re-construction of the composite service. Future development of this planning graph will include the introduction of the dynamic way of aspect oriented programming and add comparison results.

A Modular Aspect-Oriented Programming Approach of Join Point Interfaces

This paper describes and analyzes the main differ-ences and advantages of the Join Point Interfaces (JPI) as an Aspect-Oriented Programming (AOP) approach for the modular software production concerning the standard aspect-oriented pro-gramming methodology for Java (AspectJ) to propose a structural modeling approach looking for modular software solutions. Using a Software Engineering point-of-view, we highlight the relevance of structural and conceptual design for JPI software applications. We model and implement a classic example of AOP using AspectJ and JPI as an application example to review their main difference and highlight the JPI consistency between products (models and code). Our proposal of UML JPI class diagrams allows the definition of oblivious classes which know about their JPI connections, an essential element to adapt and transform tradition like-AspectJ AOP solutions to their JPI version. Thus, for the modular software production and education, JPI seems an ideal software development approach.

Achieving dynamicity in security policies enforcement using aspects

The dynamic configuration and evolution of large-scale heterogeneous systems has made the enforcement of security requirements one of the most critical phases throughout the system development lifecycle. In this paper, we propose a framework architecture to associate the security policies with the specification and the execution phases of applications defined for these systems. Our proposed framework is based on an aspect-oriented programming approach and on the organization-based access control model to dynamically enforce and manage the access and the usage control. The deployment of the framework modules, proposed in this paper, takes into account the changes that may occur in the security policy during the application execution. We also present the implementation as well as the evaluation of our proposition.

Damon: A distributed AOP middleware for large-scale scenarios

Context The development of distributed applications in large-scale environments has always been a complex task. In order to guarantee non-functional properties like scalability or availability, developers are usually faced with the same problems over and over again. These problems can be separated in distributed concerns, as for example, distribution, load-balancing or replication, just to name a few. Nevertheless, none of the current solutions in adaptive middleware area, like Aspect-Oriented Programming (AOP), is capable of implementing these distributed concerns transparently. Objective In this article, we present a distributed AOP middleware for large-scale development, called Damon. Its main goal is to implement true distributed aspects, which enables the use of distributed concerns in applications that were not specifically designed for distributed or large-scale scenarios. Method Our middleware comprises two main layers: a distributed composition model and a scalable deployment platform. The distributed composition model envisages separation of distributed aspects, taking the necessary features from component models, like distribution facilities and connectors, and from computational reflection, like introspection and meta-levels. This recursive and fully distributed model provides its own Architecture Description Language (ADL), and thus allows low dependency and high cohesion among distributed aspects. Additionally, our model is built on top of a deployment platform where distributed aspects are disseminated and activated in individual or grouped hosts. This platform benefits from peer-to-peer and dynamic AOP substrates to implement its services in a decentralized, decoupled, and efficient way. Results Therefore, our middleware solution reduces the complexity of distributed application development, managing separated functionalities, and enabling necessary services like transparent reconfiguration and deployment at runtime. Finally, we have implemented a functional prototype and we conducted several experiments using the PlanetLab testbed. Conclusion Our distributed AOP approach fulfills the large-scale scenarios requirements, and represents a solid building block for future distributed transparent infrastructures.

Towards aspect-oriented functional--structural plant modelling.

Functional-structural plant models (FSPMs) are used to integrate knowledge and test hypotheses of plant behaviour, and to aid in the development of decision support systems. A significant amount of effort is being put into providing a sound methodology for building them. Standard techniques, such as procedural or object-oriented programming, are not suited for clearly separating aspects of plant function that criss-cross between different components of plant structure, which makes it difficult to reuse and share their implementations. The aim of this paper is to present an aspect-oriented programming approach that helps to overcome this difficulty. The L-system-based plant modelling language L+C was used to develop an aspect-oriented approach to plant modelling based on multi-modules. Each element of the plant structure was represented by a sequence of L-system modules (rather than a single module), with each module representing an aspect of the element's function. Separate sets of productions were used for modelling each aspect, with context-sensitive rules facilitated by local lists of modules to consider/ignore. Aspect weaving or communication between aspects was made possible through the use of pseudo-L-systems, where the strict-predecessor of a production rule was specified as a multi-module. The new approach was used to integrate previously modelled aspects of carbon dynamics, apical dominance and biomechanics with a model of a developing kiwifruit shoot. These aspects were specified independently and their implementation was based on source code provided by the original authors without major changes. This new aspect-oriented approach to plant modelling is well suited for studying complex phenomena in plant science, because it can be used to integrate separate models of individual aspects of plant development and function, both previously constructed and new, into clearly organized, comprehensive FSPMs. In a future work, this approach could be further extended into an aspect-oriented programming language for FSPMs.

Impact of aspect-oriented programming on software development efficiency and design quality: an empirical study

The aspect-oriented programming (AOP) approach is supposed to enhance a system's features such as modularity, readability and simplicity. Owing to a better modularisation of crosscutting concerns, the developed system implementation would be less complex, and more readable. Thus, software development efficiency would increase, so the system would be created faster than its object-oriented programming (OOP) equivalent. An empirical study of a web-based system development is carried out to examine AOP against OOP approach with regard to software development efficiency and design quality. The study reveals that the AOP approach appears to be a fullfledged alternative to the pure OOP approach. Nevertheless, the impact of AOP on software development efficiency and design quality was not confirmed. In particular, it appeared that design quality metrics were not significantly associated with using AOP, instead of OOP. It is possible that the benefits of AOP will exceed the results obtained in the present study for experiments with larger number of subjects.

Tool-Supported Refactoring of Existing Object-Oriented Code into Aspects

Aspect-oriented programming (AOP) provides mechanisms for the separation of crosscutting concerns - functionalities scattered through the system and tangled with the base code. Existing systems are a natural testbed for the AOP approach since they often contain several crosscutting concerns which could not be modularized using traditional programming constructs. This paper presents an automated approach to the problem of migrating systems developed according to the object-oriented programming (OOP) paradigm into aspect-oriented programming (AOP). A simple set of six refactorings has been defined to transform OOP to AOP and has been implemented in the AOP-migrator tool, an Eclipse plug-in. A set of enabling transformations from OOP to OOP complement the initial set of refactorings. The paper presents the results of four case studies, which use the approach to migrate selected crosscutting concerns from medium-sized Java programs (in the range of 10K to 40K lines of code) into equivalent programs in AspectJ. The case study results show the feasibility of the migration and indicate the importance of the enabling transformations as a preprocessing step

From Composition Filters to AspectJ: A Platform Specific Model Transformation

Both model driven architecture (MDA) and aspect oriented programming (AOP) are promising paradigms that are very attractive for the software engineering community. While the former is an approach to application design and implementation using models as first class entities, the latter advocates the separation of concerns as an approach to tackle most software development and maintenance problems. MDA and AOP can be related in various ways and their combination seems to be a promising issue. In this article, we focus on the transformation of two AOP approaches, composition filters (CF) and AspectJ, considered as platform specific metamodels within the MDA context. We propose a transformation of CF models into AspectJ models using a syntax directed translation and a set of transformation templates. In addition to being easy to implement, our transformation approach covers the most important concepts of CF.

Improving the efficiency of adaptive middleware based on dynamic AOP

Aspect-Oriented Programming (AOP) is used to express modular and orthogonal functionality in software components. The orthogonal functionality is programmed into an aspect, join points are used to describe where in the code the aspect should be inserted. Then the aspect is woven into the original program. Unlike compile time based strategies, dynamic AOP allows aspects to be woven at runtime. This has been shown to be very useful to adapt applications without interrupting service in a wide range of settings (business applications, wireless networks, robotics, etc.), thereby making dynamic AOP a prime candidate for supporting advanced, adaptive middleware platforms. A potential drawback of dynamic AOP is the performance overhead. In this paper, we tackle the performance problem by proposing a mechanism to implement dynamic AOP through method code replacement at runtime. The idea is to use the join points not to trigger the execution of the aspect (or advice) as it is done in most systems but to trigger the recompilation of the original code. The recompiled code contains the advice already woven into it or the callbacks to the corresponding advice, thereby greatly increasing the efficiency of the dynamic AOP process. In the paper we describe the technique, discuss extensive benchmarks to evaluate the performance gain of this approach, and compare the resulting system to other dynamic AOP approaches.