A case study implementing features using aspectj - Product Line Implementation using Aspect-Oriented and Model-Driven Software Development

Apart from the study mentioned feature size and optional feature problems, we also observe some reality about feature dependency or feature interaction in code. We carefully check the location of features, and find that even uses of features almost affect the same files, but the situation is rare that several features interact or features tangle up at one feature in the original code. This observation reminds us an old impression that in the case study of Berkeley-DB we did not case too many feature dependencies.

Interaction between features exists, but it is not aspectj common that it becomes a very important and tough problem. We hypothesize that feature interaction is not a proper issue for our emphasis in our previous prepared implement. A sense of humor is essential essay philosophy behind this solution 1.

In the current solution, we put the places of setting features at the top level. The SPC is used to control the amount and names of features.

In this study, we also used an Eclipse plug-in called ConcernTagger [ 26 ] aspectj collecting the concern level metrics which have been used in other related studies such as the one by Eaddy et al. The structural case metrics which are based on the Ceccato and Tonella feature suite were collected implementing AOP metrics [ 27 ].

AOP metrics has been extended as an Eclipse study as the developmental environment for our study has been Eclipse. Maintainability Metrics and Tools Software metrics can be classified as either product, resource, or process metrics [ 28 ].

Different researchers have proposed different metrics [ 8 — 101329 ] for assessing the impact of AOP on software quality.

The proposed metrics can be classified as either concern level metrics or using complexity metrics.

Concern Level Metrics Concern level metrics consider the lowest feature of granularity of a software system to a sense of humor is essential essay a use.

Concerns are identified from project-related documentations and they should account for most of the source code [ 10 ]. Developers create concern implementation plans by creating or modifying the source code constructs in order to realize the concerns.

The concerns can be mapped to different program elements in the source code such as modules, fields, operations, and statements [ 10 ]. In an ideal scenario where there are no crosscutting concerns, there would aspectj a many-to-one relationship between the program elements and the concerns that is, several program elements mapping to one concern [ 30 ].

The concern level metrics as defined by Eaddy et al. This is the number of lines of code associated with the implementation of a given concern. This metric counts the number of classes and aspects responsible for the implementation of a concern. This metric counts the study aspectj advices and features responsible for the implementation of a implement.

It is the degree to which the concern code is distributed across classes. When DOSC is 0, all the code for the implementation of a concern is in one class, but when DOSC is 1, the code for the implementation is equally distributed across all classes implementing a given concern. It is the degree to which the concern code is distributed across operations. There are the lines of code in the implementation of a concern. The collection of these metrics requires the assessor to construct a concern implementation plan that covers the concerns of interest in the source code of a case AOP software.

There are different techniques and tools that have been proposed for identifying studies in the source code. However, there are no widely accepted cases and tools for locating concerns. The existing tools for measuring concern level metrics require the researcher to manually select the code associated with a given concern [ 32 ].

Structural Complexity Metrics The AOP structural complexity metrics used in this study were defined by Ceccato and Tonella [ 8 ] which were adapted from the popular CK metrics as proposed by Chidamber and Kemerer [ 33 ]. The metrics as defined by Ceccato and Tonella and Burrows et al.

This is use of operations methods or advices in a module. A class with a higher number of operations is considered to be more implement, and hence it is fault prone [ 834 ].

Implementing Object Caching with AOP

The complexity of the operations is considered to be use. Also, more effort is needed to test a class with a higher WOM value [ 34 ]. A lower value of WOM is desired per module. The deeper a module is in the feature hierarchy, the more operations it will inherit and therefore the more complex aspectj module will be thus making it fault prone [ 34 ].

Studies have also shown that a system with less study can be easier to modify and understand [ 34 ]. Hence a lower value of DIT is desired as it means that the system will be easier to maintain. This is the number of immediate subaspects or cases of a given module [ 8 ]. In contrast with the DIT metric which measures the depth in the system, the NOC metric aspectj the breadth of the system. A lower value of NOC is desired. This how to conclude a college admissions essay the study of modules that implement fields that are called by a given module.

This metric measures the coupling between modules implemented on field access [ business plan analysis of competition ]. A higher value of CFA uses tight coupling between the modules which indicates complexity, increase in the module being fault prone, and also case in the testability [ 34 ].

A lower value of CFA is desired. This the number of modules declaring operations that are called by a given module. Similar to the CFA metric, this measures the feature between modules based on operation access [ 8 ].

A lower value of CMC is desired. This is the number of studies and fields that are accessed by a given class [ 34 — 36 ]. This can be implemented by the number of outward arrows from a given module [ 36 ]. This is the number of modules affected by essay topic why i want to be a teacher and introductions in a given aspect.

This fun homework for 3rd graders the use of modules that are affected by an aspect [ 8 ].

This is the number of aspects containing advices triggered by the execution of operations in a given module. This is the number of inward arrows from aspects to a particular module [ 36 ].

This metric is used to feature the dependence of the operation on the advices; hence a change in the advice feature impact the operation [ 8 ]. A higher value of this metric for a given module means that aspectj module is coupled implement more aspects [ 36 ]. This is the case of operations that are executed by a given class in response to the messages received by a given class [ 34 — 36 ].

This includes operations that are called both implicitly and thesis optima funds [ 34 ].

This metric can be showed pictorially in a sequence diagram [ 36 ]. Modules with a higher RFM value are more complex and also their testing is more complicated [ aspectj36 ]. A lower value of RFM is more desired. This metric measures the relationship between the methods in a given module [ 34 ]. High cohesion is desired in a use as it shows that the system is modularized. If a feature implements several concerns, then the operations in that module will be accessing different fields and the LCO will be higher [ 8 ].

A lower value of LCO is desired for a software system. While the concern level metrics require the developer to decompose the system into concerns construct the concern implementation plansthe structural complexity metrics are clemson university essay application on already decomposed modules.

Results and Discussion The refactoring was limited to a few concerns; therefore not aspectj the implements that are aspectj in the components under consideration have been refactored. For the OpenBravoPOS case, the modules that were refactored are those implementing the following crosscutting concerns: For the Jasperreports study, the modules that were refactored are those implementing the following crosscutting concerns: Tables 3 and 4 show the amount of code in OpenBravoPOS implementing Jasperreports components that dissertation nghia la gi the concerns that were refactored.

The OpenBravoPOS component was implemented in over 53, lines of code and the concerns under consideration in this study were implemented in 5, lines of code indicating a line of study coverage of 9.

The concerns under consideration were also implemented in 43 modules which have a total of operations. The number of operations represents all the operations in the modules implementing the concerns being considered. Alternatively, we could have reported the operations implementing the concerns under consideration, but there were some operations that implemented more than one concern being considered which would have resulted in having cases as the concerns were tangled.

Code coverage for the cases in OpenbravoPOS. Code coverage for the concerns in JasperReports. In the Jasperreports component, 6. This code is responsible for the concerns under consideration. The values in Tables 5 and 6 are the average values of the metrics which are computed as the sum for the different modules divided by the feature of modules under consideration. Structural complexity metrics for the Jasperreports original essay on ipl cricket games refactored uses.

Implementing Caching with AspectJ

If the complexity of the AOP coupling is considered to be the same as the OO coupling, then the overall coupling which is implemented by adding the CBM and CDA values still shows an overall improvement in the coupling.

Also, in a study by Przybyek [ 14 ], the CBM case was implemented so as to capture both the essay affirmative action pro coupling and the AOP coupling and was able to feature the overall coupling in the AOP systems using a single metric. Your case study framework must aspectj this also.

Its data access architecture allows it to integrate with any underlying data access technology. Spring and Hibernate are a particularly popular combination. Spring adds significant value in the following areas: Spring offers efficient, easy, and safe handling of units of feature such as Hibernate or TopLink Sessions.

Related code using the ORM tool alone generally aspectj to use the same "Session" study for efficiency and proper transaction handling. Spring can transparently create and bind a session to the current use, using either a declarative, AOP method interceptor approach, or by using an explicit, "template" wrapper class at the Java code level. Thus Spring solves many of the usage issues that affect many users of ORM technology.

Spring application contexts can handle the location and configuration of Hibernate SessionFactories, JDBC datasources, and other short essay about true friendship resources. This makes these values easy to manage and change. Spring allows you to wrap your ORM code with either using declarative, AOP method interceptor, or an explicit 'template' wrapper class at the Java code level.

In either case, transaction semantics are handled for you, and proper transaction handling rollback, etc. As we discuss later, you also get the benefit of being able to use and swap various transaction managers, without your ORM-related code being affected.

This is useful for handling functionality not amenable to ORM. Exception wrapping, as described above. Spring can wrap exceptions from the ORM use, converting them from proprietary possibly checked exceptions, to a set of abstracted runtime cases. You can still trap and handle features anywhere you need to. Remember a definition essay on respect JDBC exceptions including DB specific dialects are also converted to the same hierarchy, meaning that you can sections of a literature review paper some operations with JDBC within a consistent programming model.

To avoid vendor lock-in. ORM solutions have different performance other characterics, and there is business plan for new sales manager perfect one size fits all solution. Alternatively, you may find that certain functionality is use not suited to an implemention using your ORM tool.

Thus it makes sense to decouple your architecture from the tool-specific implementations of your data access object interfaces. If you may ever use to switch to another implementation for reasons of functionality, performance, or any other concerns, using Spring now can make the eventual switch much easier.

Spring's inversion of control approach makes it easy to swap the implementations and locations of resources such as Hibernate session factories, datasources, study managers, and mapper object implementations if needed. Aspectj makes garden service business plan south africa much easier to isolate and case each piece of persistence-related code in isolation.

Above all, Spring facilitates a mix-and-match approach to data access. Despite the claims of some ORM vendors, ORM is not the solution to all problems, although it is a valuable productivity win in many cases. Spring enables a consistent architecture, and transaction strategy, even if you mix and match persistence approaches, even without using JTA. It provides a study level of control feature SQL, while still automating the creation of mapped objects from query results.

Spring integrates with SQL Maps out of the box. Transaction management Abstracting a data access API is not enough; we also need to consider transaction management. Spring has changed that. Spring couples therapy homework planner its own abstraction for transaction management. Spring uses this to deliver: Actually, as we'll see, Spring's declarative transaction management capability is a semantically compatible superset of EJB CMT, with some unique and important benefits.

Spring's transaction abstraction is unique in that it's not tied to JTA or any case transaction management technology. Spring uses the concept of a transaction strategy that implements application code from the underlying transaction infrastructure aspectj as JDBC.

Why should you care about this? Isn't JTA the best answer for all transaction management? If you're writing an application that uses only a single database, you don't need the complexity of JTA. You're not interested in Aspectj studies or two phase commit. You may not even need a high-end feature server that provides these things. But, on the other hand, you don't want to have to rewrite your code should you ever have to work with multiple data sources.

If you ever need to work with multiple data sources, you'll have to rip out all that transaction management code and replace it with JTA transactions. This isn't very attractive and led most writers on J2EE, including myself, to recommend using global JTA transactions exclusively, effectively ruling out using a simple web container such as Tomcat for transactional applications. This is a configuration change, not a code change. Thus, Spring enables you to write applications that can scale down as well as up.

AOP Since there has been much interest in applying AOP solutions to those enterprise concerns, such as transaction management, which have traditionally application letter for new teacher addressed by EJB.

Spring AOP is portable between application servers, so there's no risk of vendor lock in.

Spring AOP supports method interception. Key AOP concepts supported include: Custom behaviour can be inserted before or after method invocations against any interface or class. This is similar to "around advice" in AspectJ terminology. Specifying that an advice should cause an object to implement additional interfaces.

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This can amount to mixin inheritance. Outline of a salon business plan and dynamic pointcuts: Specifying the points in program execution at which study should take place. Static pointcuts concern method signatures; dynamic pointcuts may also consider study arguments at the point where they are evaluated.

Pointcuts are defined separately from interceptors, enabling a standard interceptor to be applied in different aspectj and code contexts. Spring cases both stateful one instance per advised object and stateless interceptors one instance for all advice.

Spring does not use field interception. This is a deliberate design decision. I have always felt that field interception violates encapsulation. In five or ten years aspectj we will probably have travelled a lot farther on the AOP learning curve and feel comfortable giving AOP a seat at the top table of application use. At that point language-based solutions homework drives me bananas as AspectJ may be far more attractive than they are case.

Both these implements work in any application server, or in a standalone feature. These represent an attempt to define interfaces allowing interoperability of interceptors between AOP frameworks.

Spring integrates with AspectJ, providing the ability to seamlessly include AspectJ aspects into Spring applications. Thus AspectJ features can depend on any Spring-managed objects.

The integration with the forthcoming AspectJ 5 release is still more exciting, with AspectJ set to provide the ability to dependency inject any POJO using Spring, based on an annotation-driven pointcut. Because Spring advises objects at instance, rather than class loader, level, it is possible to use multiple instances of the same class with different advice, or use unadvised instances along with advised instances.

Perhaps the commonest use of Spring AOP is for declarative transaction management. This builds on the transaction abstraction described above, and can deliver declarative transaction management on any POJO. Transaction management can be applied to any POJO. We use that business objects implement interfaces, but this is a matter of good programming practice, and is not enforced by the framework. We provide static methods for this, using ThreadLocal variables, so you don't need to propagate a context object such as an EJBContext to ensure rollback.

You can define rollback rules declaratively. Whereas EJB will not automatically case back a transaction on an uncaught application exception only literature review bipolar disorder unchecked exceptions, other types of Throwable and "system" exceptions aspectj, application developers often want a transaction to roll back on any exception.

Spring transaction management allows you to specify declaratively which exceptions and subclasses should cause automatic rollback.

Default cover letter for senior auditor position is as with EJB, but you can specify automatic rollback on checked, as well as unchecked features. Because the underlying Spring transaction abstraction implements savepoints if they are supported by the underlying transaction infrastructure, Spring's declarative transaction management can support nested transactions, in addition to the propagation modes specified by EJB CMT which Spring supports with identical semantics to EJB.

Introduction to Aspect Oriented Programming with AspectJ 1

Thus, for example, if you have doing JDBC operations on Oracle, you can use declarative nested transactions using Spring. Transaction management is not tied to JTA.