Convertir aplicaciones de escritorio en aplicaciones móviles con Java

El presente artículo introduce un proceso básico para convertir aplicaciones J2SE en aplicaciones JavaFX, centrando su atención en programas locales que manejen persistencia sobre archivos texto y que deseen ser migrados a teléfonos inteligentes. Igualmente, entrega pautas para generar desde sus inicios en pasos ordenados una aplicación JavaFX sin tener que contar con la experiencia previa del programa en J2SE o en ambientes de escritorio. Para esta nueva modalidad de programación donde se pretende como mínimo la misma calidad, presentación y funcionalidad de las aplicaciones de escritorio pero con el aprovechamiento máximo de los recursos de un dispositivo móvil, se presentó a un grupo de estudiantes en un curso de programación avanzado de Tecnología en Informática de la Corporación Universitaria Minuto de Dios (UNIMINUTO) una aplicación ya diseñada e implementada en J2SE para ser convertida a JavaFX. Al finalizar el trabajo se conservó la integridad y lógica del desarrollo original a su nueva versión sin necesidad de tener el conocimiento y la agilidad en ambos lenguajes de programación

Services in pervasive computing environments : from design to delivery

The work presented in this thesis is based on the assumption that modern computer technologies are already potentially pervasive: CPUs are embedded in any sort of device; RAM and storage memory of a modern PDA is comparable to those of a ten years ago Unix workstation; Wi-Fi, GPRS, UMTS are leveraging the development of the wireless Internet. Nevertheless, computing is not pervasive because we do not have a clear conceptual model of the pervasive computer and we have not tools, methodologies, and middleware to write and to seamlessly deliver at once services over a multitude of heterogeneous devices and different delivery contexts. Our thesis addresses these issues starting from the analysis of forces in a pervasive computing environment: user mobility, user profile, user position, and device profile. The conceptual model, or metaphor, we use to drive our work is to consider the environment as surrounded by a multitude of services and objects and devices as the communicating gates between the real world and the virtual dimension of pervasive computing around us. Our thesis is thus built upon three main “pillars”. The first pillar is a domain-object-driven methodology which allows developer to abstract from low level details of the final delivery platform, and provides the user with the ability to access services in a multi-channel way. The rationale is that domain objects are self-contained pieces of software able to represent data and to compute functions and procedures. Our approach fills the gap between users and domain objects building an appropriate user interface which is both adapted to the domain object and to the end user device. As example, we present how to design, implement and deliver an electronic mail application over various platforms. The second pillar of this thesis analyzes in more details the forces that make direct object manipulation inadequate in a pervasive context. These forces are the user profile, the device profile, the context of use, and the combinatorial explosion of domain objects. From the analysis of the electronic mail application presented as example, we notice that according to the end user device, or according to particular circumstances during the access to the service (for instance if the user access the service by the interactive TV while he is having his breakfast) some functionalities are not compulsory and do not fit an adequate task sequence. So we decided to make task models explicit in the design of a service and to integrate the capability to automatically generate user interfaces for domain objects with the formal definition of task models adapted to the final delivery context. Finally, the third pillar of our thesis is about the lifecycle of services in a pervasive computing environment. Our solutions are based upon an existing framework, the Jini connection technology, and enrich this framework with new services and architectures for the deployment and discovery of services, for the user session management, and for the management of offline agents

Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow

An Autonomic Cross-Platform Operating Environment for On-Demand Internet Computing

The Internet has evolved into a global and ubiquitous communication medium interconnecting powerful application servers, diverse desktop computers and mobile notebooks. Along with recent developments in computer technology, such as the convergence of computing and communication devices, the way how people use computers and the Internet has changed people´s working habits and has led to new application scenarios. On the one hand, pervasive computing, ubiquitous computing and nomadic computing become more and more important since different computing devices like PDAs and notebooks may be used concurrently and alternately, e.g. while the user is on the move. On the other hand, the ubiquitous availability and pervasive interconnection of computing systems have fostered various trends towards the dynamic utilization and spontaneous collaboration of available remote computing resources, which are addressed by approaches like utility computing, grid computing, cloud computing and public computing. From a general point of view, the common objective of this development is the use of Internet applications on demand, i.e. applications that are not installed in advance by a platform administrator but are dynamically deployed and run as they are requested by the application user. The heterogeneous and unmanaged nature of the Internet represents a major challenge for the on demand use of custom Internet applications across heterogeneous hardware platforms, operating systems and network environments. Promising remedies are autonomic computing systems that are supposed to maintain themselves without particular user or application intervention. In this thesis, an Autonomic Cross-Platform Operating Environment (ACOE) is presented that supports On Demand Internet Computing (ODIC), such as dynamic application composition and ad hoc execution migration. The approach is based on an integration middleware called crossware that does not replace existing middleware but operates as a self-managing mediator between diverse application requirements and heterogeneous platform configurations. A Java implementation of the Crossware Development Kit (XDK) is presented, followed by the description of the On Demand Internet Computing System (ODIX). The feasibility of the approach is shown by the implementation of an Internet Application Workbench, an Internet Application Factory and an Internet Peer Federation. They illustrate the use of ODIX to support local, remote and distributed ODIC, respectively. Finally, the suitability of the approach is discussed with respect to the support of ODIC

On the Development of Real-Time Multi-User Web Applications

With the increasing popularity of the World Wide Web (WWW), end-user applications are moving from desktop to the browser. Web applications have several benefits over native applications: web applications have worldwide availability for any browsing capable device without prior installations. In addition, web applications are easy to distribute and update – once deployed, a web application is instantly available worldwide and further modifications to the system are propagated automatically. The current trend seems to be that web applications are offering collaboration, social connections, and user to user interactions as key features. This can be seen, for example, in the popularity of Facebook, Flickr, and Twitter. Despite all the benefits of the Web, web applications are suffering from the shortcomings in underlying technologies. The Web is strongly rooted in information sharing, and the current technical solutions isolate users rather than make them aware of each other. Since the data cannot be pushed from server to a client, the client must always initiate the communication, which causes a considerable impediment for real-time multi-user web applications, like online chats that have several concurrent users continuously interacting with each other. For such systems, it would be practical if the server could push messages to clients. As a further obstacle, most web application frameworks isolate users in their private sessions that only interact indirectly via the database. This main contribution of this thesis is to make the development of real-time multi-user web applications easier. We elaborate on the difficulties in implementation and design and introduce methods of circumventing them. The main argument is that the Web, the available technology stack, and the frameworks are difficult to use for developing real-time multi-user web applications. However, by selecting the proper approach, the problems can be solved. In this thesis, we have divided the frameworks in groups based on how they make separation of concerns between the client and the server. The separation is important as it determines the thickness of the client and thus where to locate the business logic and the application state. In addition, it has effect on the synchronization of the state between the clients. To collect experiences and for backing up our assumptions, we have implemented real-time multi-user web applications for several frameworks and studied how the frameworks should be used for enabling real-time multi-user application development

Exploiting similarity patterns in web applications for enhanced genericity and maintainability

Ph.DDOCTOR OF PHILOSOPH

Vers une programmation locale et distribuée unifiée au travers de l'utilisation de conteneurs actifs et de références asynchrones.

Dans le domaine des systèmes distribués, la notion de mobilité du code est à l’origine de nombreux travaux visant à améliorer les performances des applications parallèles (processus légers mobiles), à faciliter le développement d’applications (agents mobiles) ou à garantir la sécurité (cartes à puces). Dans ce contexte, nous montrons que les systèmes d’agents mobiles ont peu à peu disparu au profit de plates-formes d’exécution asynchrones. Nous présentons une nouvelle abstraction – appellée conteneur actif – qui est issue d’une modélisation en π-calcul d’un système d’agents mobiles, et qui semble être une brique de base avec laquelle les applications distribuées peuvent être conçues. Le développement d’une implémentation de cette abstraction en Java a fait apparaître un problème lié à la gestion de la concurrence dans les applications, distribuées ou non. Nous décrivons donc la notion de référence asynchrone – notre solution à ce problème – qui permet d’exprimer simplement la concurrence d’exécution dans une application. Notre implémentation en Java de ce concept facilite le développement des applications multithread ées et parallèles, en évitant le recours problématique aux threads par l’utilisation exclusive d’un unique paradigme : l’appel de méthode. Ce dernier peut se décliner en de multiples versions : synchrone, asynchrone, local ou distant. L’ensemble de nos travaux est disponible sous licence libre LGPL au sein d’une plateforme opérationnelle et documentée appellée Mandala qui est brièvement décrite.In the domain of distributed systems, several projects focus on mobile code in order to enhance the performance of parallel applications (mobile threads), to make easier the development of applications (mobile agents) or to guarantee security (smart cards). In this context, we show how mobile agent systems have basically disappeared in favor of asynchronous execution frameworks. We present a new abstraction – called active container – originating from a model of a mobile agents system. It seems to be a base layer on top of which distributed applications can be developped. A Java implementation of this abstraction raises a problem related to the management of concurrency in applications, distributed or not. We describe the notion of asynchronous reference – our solution to this problem – which allows to express concurrency quite easily. Our Java implementation of this concept eases the development of multithreaded and parallel applications avoiding the problematic use of threads by the exclusive use of a single paradigm: method invocation. This can be: synchronous, asynchronous, local or remote. Our work is available as an open-source LGPL licence package within a ready to use and documented framework called Mandala which is briefly described

Combining SOA and BPM Technologies for Cross-System Process Automation

This paper summarizes the results of an industry case study that introduced a cross-system business process automation solution based on a combination of SOA and BPM standard technologies (i.e., BPMN, BPEL, WSDL). Besides discussing major weaknesses of the existing, custom-built, solution and comparing them against experiences with the developed prototype, the paper presents a course of action for transforming the current solution into the proposed solution. This includes a general approach, consisting of four distinct steps, as well as specific action items that are to be performed for every step. The discussion also covers language and tool support and challenges arising from the transformation