軟體即服務（Software as a Service, SaaS）是雲端運算環境下一種新興的服務模式，它的特色是將特定的應用軟體以共享軟硬體資源的方式供眾多的租戶（tenants）使用。因此，如何提供共用且有客制化功能的應用軟體就是SaaS模式的重要成功關鍵。本研究聚焦於資料庫層提供多租戶共用表格但有客制化功能的機制。讓開發人員延續一租戶一資料表的架構為基礎設計資料庫，透過SQL語句轉換機制，將SQL語句轉換為操作共享表格的語句執行，以大幅減化開發人員的工作。本研究包含兩個部份，一是資料綱要對應表(Schema Mapping Table)，協助開發人員將單租戶資料庫架構轉換為塊狀表格(chunk table)的共用資料綱要方式；另一個是SQL語句自動轉換工具，透過剖面技術織入JDBC程式集中，在應用系統執行期間，將SQL語句，從一租戶一資料表寫法轉換為共享表格的方式執行。故只需將資料表改為共用架構即可使用，達到提升多租戶系統開發速度並提高資源使用率的目的。 / Software as a service (SaaS) is an emerging service model of cloud computing, which is characterized by providing software that charges on a usage basis over shared hardware and software resources for a large number of tenants to use. Therefore, how to provide shared tables and customization of the applications is an important key to success in the SaaS model. This study focuses on how to enable multi-tenancy on the database layer Developers can extend a private table structure-based application to a shared database one through the proposed SQL rewriting mechanism. This approach can greatly simplify the developer's work. Our approach consists of two parts, first is Schema Mapping Table that helps developers to convert single-tenant database architecture into the chunk table schema; another is SQL statement conversion tools that works by enhancing the JDBC library as an aspect in the AspectJ language. During the execution of the application, a SQL statement is rewritten from the private table based format into chunk table based statement. In this way, we are able to enhance an application with multitenant shared tables that improve resource utilization.

<p>In this diploma thesis we have aimed to identify metrics that accommodate two chosen system quality factors and implementing the selected metrics in a metrics tool. The metrics chosen should measure change in the system quality factors reusability and maintainability for the middleware system COS at Telenor Mobile and similar systems. The metrics tool should support the aspect-oriented programming language AspectJ, and is planned to be a plugin to the open source code analysis framework XRadar. Changes due to introduction of aspects are of particular interest.</p><p>We have through a GQM process identified the following subcharacteristics for the chosen system quality factors: modularity, testability, analyzability, changeability and stability. Questions are formulated to analyze these sub factors, and metrics that can answer the questions are chosen.</p><p>We have implemented the tool AspectMetrics, which calculate metrics on Java and AspectJ code and generates an XML report containing the measurement results. A transformation from XML to HTML web pages is also provided. The metrics tool can measure size metrics, like the number of statements and the number of classes, coupling, fan-in/fan-out, cohesion and advice-in/advice-out. Advice-in and advice-out are two new metrics which respectively measures how many advice a class (or aspect) is affected by and how many joinpoints an advice hits on. These metrics are inspired by the concept for the fan-in and fan-out metrics.</p><p>The tool has been used to analyze two versions of the system DIAS v.2.0, which is a part of a diploma study in 2000. We have in our preparation project in 2003 added aspects to the DIAS system while keeping the system functionally equal to the original version. We have used our metrics tool to calculate the differences between the system with and the system without aspects. The introduction of aspects gave a positive change in coupling, fan-in/fan-out and size measures, while cohesion was negatively affected. The metrics thus, overall, indicated a positive change to the subcharacteristics testability, analyzability, changeability and stability and both the main quality factors. There was no indication of a positive change to modularity.</p><p>The analysis of the measurement results indicates that most of the metrics perform as intended. The size metrics, coupling, fan-in/fan-out, and advice-in/advice-out all gave results that corresponded to what we had expected. However, the cohesion measure did not behave in a way that could be correlated to the actual changes performed on the code. A closer analysis showed that moving and merging of functionality could result in either an increase or a decrease in cohesion. Thus we find that cohesion, at least in its current form, is not a suitable metric when using aspect-oriented programming. Further, this gave reason to reinvestigate the disappointing modularity results. With a reworked set of criteria we also found indication of improved modularity.</p>

In this diploma thesis we have aimed to identify metrics that accommodate two chosen system quality factors and implementing the selected metrics in a metrics tool. The metrics chosen should measure change in the system quality factors reusability and maintainability for the middleware system COS at Telenor Mobile and similar systems. The metrics tool should support the aspect-oriented programming language AspectJ, and is planned to be a plugin to the open source code analysis framework XRadar. Changes due to introduction of aspects are of particular interest. We have through a GQM process identified the following subcharacteristics for the chosen system quality factors: modularity, testability, analyzability, changeability and stability. Questions are formulated to analyze these sub factors, and metrics that can answer the questions are chosen. We have implemented the tool AspectMetrics, which calculate metrics on Java and AspectJ code and generates an XML report containing the measurement results. A transformation from XML to HTML web pages is also provided. The metrics tool can measure size metrics, like the number of statements and the number of classes, coupling, fan-in/fan-out, cohesion and advice-in/advice-out. Advice-in and advice-out are two new metrics which respectively measures how many advice a class (or aspect) is affected by and how many joinpoints an advice hits on. These metrics are inspired by the concept for the fan-in and fan-out metrics. The tool has been used to analyze two versions of the system DIAS v.2.0, which is a part of a diploma study in 2000. We have in our preparation project in 2003 added aspects to the DIAS system while keeping the system functionally equal to the original version. We have used our metrics tool to calculate the differences between the system with and the system without aspects. The introduction of aspects gave a positive change in coupling, fan-in/fan-out and size measures, while cohesion was negatively affected. The metrics thus, overall, indicated a positive change to the subcharacteristics testability, analyzability, changeability and stability and both the main quality factors. There was no indication of a positive change to modularity. The analysis of the measurement results indicates that most of the metrics perform as intended. The size metrics, coupling, fan-in/fan-out, and advice-in/advice-out all gave results that corresponded to what we had expected. However, the cohesion measure did not behave in a way that could be correlated to the actual changes performed on the code. A closer analysis showed that moving and merging of functionality could result in either an increase or a decrease in cohesion. Thus we find that cohesion, at least in its current form, is not a suitable metric when using aspect-oriented programming. Further, this gave reason to reinvestigate the disappointing modularity results. With a reworked set of criteria we also found indication of improved modularity.

對於不同團隊協同開發大型的應用程式，常會面臨應用程式自行處理例外事件而未正確回報用戶之執行結果與無法得知封閉式類別庫內部詳細呼叫流程，導致偵錯不易的困擾。有鑒於此，本研究將實作一個工具，利用Aspect-Oriented Programming(AOP)特性，將AspectJ織入JDBC驅動程式並賦予存取紀錄儲存之功能，既可免除應用程式本身未針對資料庫儲存存取紀錄的問題，直接儲存所有存取紀錄，亦不影響資料庫操作，更可以分辦造成錯誤發生的程式以釐清問題，有效幫助偵錯。此工具適用於任何使用JDBC介面去存取資料庫管理系統（DBMS）之JAVA應用程式，它能在不影響應用程式的情況下客製化儲存應用程式透過JDBC驅動程式連結資料庫管理系統（DBMS）的存取紀錄，並利用存取紀錄進行分析並複製存取行為，以提供更豐富的資訊進一步協助偵錯。 / When using a large database application which is jointly designed by different teams, the administrators are often confronted with a problem that the application handles the exception spontaneously and often fails to report back the result of user’s execution. Therefore, the administrator can’t be informed of the details of the calling flow in case of exceptions. This will make it not only difficult to find which part of the application goes wrong, but also hard to fix. To resolve this problem, this thesis designs and implements an aspect-based debugging tool for such database applications. The key idea behind the tool is that, instead of adapting the large application for logging database access activities, we target at the JDBC driver and make JDBC driver capable of saving access log. This tool works for any JAVA applications that use JDBC interface to access database. Without any modification to the user-level application, this tool can save the access log obtained by application which use JDBC driver to connect the database, and the administrator can customize the access log. By analyzing the access records and duplicating the access behavior, this tool provides more information to further assist in application debugging.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

While Role Based Access Control (RBAC) has been a popular topic of research over the last several years, there are some gaps in the literature that have been waiting to be addressed. One of these gaps involves the application of RBAC to free and open source software (FOSS). With the prevalence of FOSS in most information systems growing rapidly, there is a need to be able to provide a level of confidence that the software will not compromise the data integrity of an environment, nor will it enable the violation of established access controls. Additionally, when utilizing FOSS software it is desirable to do so without having to modify its source code whenever an update is released in order to maintain a secure environment; this makes adding proprietary modules both time consuming and expensive. The challenges involved in maintaining proprietary changes to FOSS generates a particular interest in an RBAC environment that could be deployed without requiring modification to the source code. Developing this type of a framework presented a significant challenge due to the software having been established prior to the definition of any security requirements that would have to be applied by the proposed framework. What this research paper shows are the results of the development of a software framework that allowed security requirements engineering to seamlessly meld with an application after it had already been developed. This framework provided a mechanism to measurably reduce the attack surface of the application against which the framework was implemented, while performing these tasks without requiring alterations to the source code of the application. Additionally, this research introduced a mechanism that was utilized to measure the effectiveness of the framework. This mechanism provided a means of comparing the relative effectiveness of different frameworks against the same software, as well as the effectiveness of a framework against different pieces of software.

Made available in DSpace on 2019-03-29T23:23:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-24 / This dissertation presents and describes CAS that is a content adaptation service for multiplatform web applications built using aspect-oriented programming. The main goals of CAS are to be applicable in applications of different business domains and the separation of content adaptation as a crosscutting concern isolated from applications business logic. It is also presented qualitative and quantitative results obtained from the case studies developed with CAS and the evaluations made. Keywords: Content Adaptation, Multiplatform Applications, Separation of Concerns, Aspect-Oriented Programming. / Esta dissertação apresenta e descreve o CAS Content Adaptation Service, um serviço de adaptação de conteúdo para aplicações web multiplataforma construído com o uso do paradigma de programação orientada a aspectos. Os objetivos pretendidos com o CAS são possibilitar sua aplicação em diferentes domínios de negócio e separar a adaptação de conteúdo como um interessa transversal isolado da lógica de negócio das aplicações. São apresentados também os resultados dos estudos de caso quantitativo e qualitativo realizados com a utilização do CAS e as avaliações feitas sobre tais resultados. Palavras-chave: Adaptação de Conteúdo, Aplicações Multiplataforma, Separação de Interesses, Programação Orientada a Aspectos.

Submitted by Pedro Henrique Rodrigues (pedro.henriquer@ufpe.br) on 2015-03-05T19:54:44Z No. of bitstreams: 2 rcaa-dissertacao.pdf: 2306258 bytes, checksum: c627fb646b9c6f3cadf93565c0b59dd9 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-05T19:54:44Z (GMT). No. of bitstreams: 2 rcaa-dissertacao.pdf: 2306258 bytes, checksum: c627fb646b9c6f3cadf93565c0b59dd9 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012-03-02 / FACEPE, CNPq, INES / Companies are adopting the Software Product Line (SPL) development paradigm to obtain significant improvements in time to market, maintenance cost, productivity, and quality of products. SPL encompasses a family of software-intensive systems developed from reusable assets. By reusing such assets, it is possible to construct a large number of different products applying various compositions. There is a variety of widely used techniques to develop SPLs, such as aspect-oriented programming (AOP), feature-oriented programming (FOP), and conditional compilation. These techniques differ in the type of composition to create a product within the SPL static or dynamically. In this context, it is important to define when certain features should be activated in the product due to specific client requirements and different application scenarios. Thereby, the binding time of a feature is the time that one decides to activate or deactivate the feature from a product. In general, static and dynamic binding times are considered. For example, products for devices with constrained resources may use static binding time instead of dynamic due to the performance overhead introduced by the latter. For devices without constrained resources, the binding time can be flexible, features can be activated or deactivated statically or users may do it on demand (dynamically). To provide flexible binding time for features, researchers proposed an AOP idiom based on AspectJ and design patterns named Edicts. The idea consists of supporting binding time flexibility of features in a modular and convenient way. However, we observe modularity problems in the Edicts idiom. Although we usually use aspects to tackle crosscutting concerns common in classes, such a problem now appears within the own aspects. Indeed, several studies indicate that these concerns hurt software modularity. This way, we observe that Edicts clones, scatters, and tangles code throughout its implementation, which may lead to time consuming tasks, such as maintaining duplicated code. This way, we develop three idioms and implement them to provide flexible binding time for features of four different applications. In addition, we evaluate Edicts and the three idioms quantitatively by means of metrics with respect to code tangling, scattering, cloning, size, and also try to guarantee that our idioms do not change feature code behavior among the different implementations.

Der Große Beleg dokumentiert die Entwicklung eines Java Code-Generators für Dresden OCL2 for Eclipse. Schwerpunkt der Arbeit liegt dabei auf der Abbildung der Object Constraint Language auf die Programmiersprache Java mit Hilfe von AspectJ.

Der Große Beleg dokumentiert die Entwicklung eines Java Code-Generators für Dresden OCL2 for Eclipse. Schwerpunkt der Arbeit liegt dabei auf der Abbildung der Object Constraint Language auf die Programmiersprache Java mit Hilfe von AspectJ.