This work concerns with dynamic evolution of applications written in Java. It investigates existing solutions implemented in both Java and other programming languages. Following part analyses complete substitution of object in running application in various situations. A framework for dynamic updating of Java-based applications is designed. The framework is implemented and is used in illustrative application. Finally, achieved results are evaluated and additional possible enhancements are stated.

Les domaines de recherche actuels, tels que l'informatique ubiquitaire et l'informatique en nuage (cloud computing), considèrent que ces environnements d’exécution sont en changement continue. Les applications dynamiques, où les composants peuvent être ajoutés et supprimés pendant l'exécution, permettent à un logiciel de s'adapter et de s'ajuster à l'évolution des environnements, et de tenir compte de l’évolution du logiciel. Malheureusement, les applications dynamiques soulèvent des questions de conception et de développement qui n'ont pas encore été pleinement explorées.Dans cette thèse, nous montrons que le dynamisme est une préoccupation transversale qui rompt avec un grand nombre d’hypothèses que les développeurs d’applications classiques sont autorisés à prendre. Le dynamisme affecte profondément la conception et développement de logiciels. S'il n'est pas manipulé correctement, le dynamisme peut « silencieusement » corrompre l'application. De plus, l'écriture d'applications dynamiques est complexe et sujette à erreur. Et compte tenu du niveau de complexité et de l’impact du dynamisme sur le processus du développement, le logiciel ne peut pas devenir dynamique sans (de large) modification et le dynamisme ne peut pas être totalement transparent (bien que beaucoup de celui-ci peut souvent être externalisées ou automatisées).Ce travail a pour but d’offrir à l’architecte logiciel le contrôle sur le niveau, la nature et la granularité du dynamisme qui est nécessaire dans les applications dynamiques. Cela permet aux architectes et aux développeurs de choisir les zones de l'application où les efforts de programmation des composants dynamiques seront investis, en évitant le coût et la complexité de rendre tous les composants dynamiques. L'idée est de permettre aux architectes de déterminer l'équilibre entre les efforts à fournir et le niveau de dynamisme requis pour les besoins de l'application. / Current areas of research, such as ubiquitous and cloud computing, consider execution environments to be in a constant state of change. Dynamic applications—where components can be added, removed and substituted during execution—allow software to adapt and adjust to changing environments, and to accommodate evolving features. Unfortunately, dynamic applications raise design and development issues that have yet to be fully addressed. In this dissertation we show that dynamism is a crosscutting concern that breaks many of the assumptions that developers are otherwise allowed to make in classic applications. Dynamism deeply impacts software design and development. If not handled correctly, dynamism can silently corrupt the application. Furthermore, writing dynamic applications is complex and error-prone, and given the level of complexity and the impact dynamism has on the development process, software cannot become dynamic without (extensive) modification and dynamism cannot be entirely transparent (although much of it may often be externalized or automated). This work focuses on giving the software architect control over the level, the nature and the granularity of dynamism that is required in dynamic applications. This allows architects and developers to choose where the efforts of programming dynamic components are best spent, avoiding the cost and complexity of making all components dynamic. The idea is to allow architects to determine the balance between the efforts spent and the level of dynamism required for the application's needs. At design-time we perform an impact analysis using the architect's requirements for dynamism. This serves to identify components that can be corrupted by dynamism and to—at the architect's disposition—render selected components resilient to dynamism. The application becomes a well-defined mix of dynamic areas, where components are expected to change at runtime, and static areas that are protected from dynamism and where programming is simpler and less restrictive. At runtime, our framework ensures the application remains consistent—even after unexpected dynamic events—by computing and removing potentially corrupt components. The framework attempts to recover quickly from dynamism and to minimize the impact of dynamism on the application. Our work builds on recent Software Engineering and Middleware technologies—namely, OSGi, iPOJO and APAM—that provide basic mechanisms to handle dynamism, such as dependency injection, late-binding, service availability notifications, deployment, lifecycle and dependency management. Our approach, implemented in the Robusta prototype, extends and complements these technologies by providing design and development-time support, and enforcing application execution consistency in the face of dynamism.

[pt] A natureza de certos sistemas de software determina que estes tenham de executar de maneira ininterrupta. Por outro lado, diversos sistemas de software são constantemente sujeitos a mudanças, por questões que incluem, mas não se limitam a, infraestrutura, correções de falhas, adição de funcionalidades e mudanças na lógica de domínio. Evolução dinâmica de software consiste em alterar aplicações durante a sua execução sem interrompê-las, mantendo-as disponíveis mesmo durante a aplicação destas modificações. Sistemas distribuídos baseados em componentes permitem decompor o software em entidades claramente separadas. Nesses casos, a evolução pode ser resumida a remoção, adição e modificação de tais entidades, e se tais atividades podem ser exercidas enquanto a aplicação está em execução, tem-se evolução dinâmica de software. Através disso, neste trabalho foi criada uma abordagem em que é possível se manipular arquiteturas distribuídas desenvolvidas sobre o middleware SCS de maneira a se minimizar a interrupção de partes do sistema enquanto certas adaptações são implantadas. Aplicamos o mecanismo em um sistema distribuído já consolidado, o CAS, que consiste em uma infraestrutura de gravação extensível com suporte a captura e acesso automáticos de mídias distribuídas. / [en] The nature of some software systems determine that they run without interruption. Furthermore, many software systems are constantly subject to change for reasons that include, but are not limited to, infrastructure changes, bug fixes, addition of functionalities, and changes in the domain logic. Dynamic software evolution consists into changing application during execution without stopping them, keeping them available even when applying these modifications. Component-based distributed systems allows decomposing software into clearly separated entities. In such cases, evolution can be summarized to removal, addition and modification of such entities, and if such activities can be performed while the application is executing, dynamic adaptation is achieved. In this work, we ve investigated an approach that aims to allow manipulation of distributed software architectures developed over the SCS middleware, in order to minimize system disruption while certain adaptations are deployed. The mechanism was tested in an already consolidated distributed system, the CAS, which consists of an extensible recording infrastructure that supports automatic capture and access of distributed medias.