Johannes Meinecke’s research while affiliated with Chemnitz University of Technology and other places

Over the last years, the need to interconnect businesses has significantly affected the Web. The Web has moved constantly from a static source of documents to a dynamic platform for distributed applications. The communication infrastructure of the Web links together applications, e.g. by exposing functionality through Web services in different architectural styles. The current strife between SOA and REST leads one to the issue which approach to choose. Supported by a formal model, we show an integrative way to incorporate service orientation and resource orientation in federated systems as a foundation for future agreements rather than a separation of the approaches.

Today's Web applications and their respective business processes reside under the control of different organizations. Establishing federations between these organizations, i.e. bringing these business processes together by transcending organizational and security borders, raises a new class of security questions concerning the management of trust relationships between the autonomous bodies that wish to work together. Based on the Webcomposition architecture model we provide a modeling approach for federated Web applications. In this paper we present a methodology for formalizing these models using the ambient calculus for use in further computation. Based on the results we help the users to identify and detect security related aspects in Web-based federations.

For a modernenterprise, it is vital to be on the Web. Beyond offeringhuman-readable Web sites, organizations increasingly use the Web as a media formachine-readable data about itself. With the help of technologies like XML feeds,RESTful Web services and semanticmarkup, new forms of enterprisesmodelsemerge in a bottom-up way. These models are easily consumable and facilitate theinteraction with departments,partners and customers.Engineering good publishingsystems is howeverextremelychallenging.On the one hand, knowledge of manytechnologies is required; on the other hand, it must be easy to extendsystems anddata models in accordance to agile businesses. In this paper, we proposea frame-work of components for publishing dynamically growingenterprisemodelson theWeb, present an implemented system and discuss its use in a case study.

Engineering methods for Web applications that do not take changes of the system environment into account are in danger of planning across purposes with reality. Modern Web applications are characterized by dynamically evolving architectures of loosely coupled content sources, components and services from multiple organizations. The evolution of such ecosystems poses a problem to management and maintenance. Up-to-date architectural information about the components and their relationships is required in different places within the system. However, this is problematic, because, manual propagation of changes in system descriptions is both costly and error-prone. In this paper, we therefore describe how the publish-subscribe principle can be applied to automate the handling of architecture changes via a loosely-coupled event mechanism. We investigate relevant architecture changes and propose a concrete system of subscription topics and event compositions. The practicality of the approach is demonstrated by means of an implemented support system that is compliant with the WS-notification specification.

The content of many innovative Web sites today often originates from beyond the application. This paper is concerned with building Web appli- cations that heavily integrate and link content from external sources, like e.g. Web services or RSS feeds. Unlike conventional applications, they are charac- terized by a very dynamic and distributed information space. In this context, traditional Web Engineering approaches suffer from the fact that they rely too much on a-priori knowledge of existing content structures. We present a sup- port system and a method for building such applications in a very flexible way. Flexibility is achieved by managing links separately from the content in a dedi- cated Web service and by composing the application from fine-grained, reus- able components that realize navigation, presentation, and interaction for the linked content.

The success of many innovative Web applications is not based on the content they produce - but on how they combine and link existing content. Older Web Engineering methods lack flexibility in a sense that they rely strongly on a-priori knowledge of existing content structures and do not take into account initially unknown content sources. We propose the adoption of principles that are also found in Component-based Software Engineering, to assemble highly extensible solutions from reusable artifacts. The main contribution of our work is a support system, consisting of a central service that manages n:m relationships between arbitrary Web resources, and of Web application components that realize navigation, presentation, and interaction for the linked content.

Die technische Realisierung eines Integrierten Informationsmanagements an Hochschulen basiert zunehmend auf dem Konzept der serviceorientierten Architekturen. Die hochgradige Heterogenität und Komplexität der resultierenden Systemlandschaften begründet den Bedarf an systematischen Ansätzen zur Unterstützung der strategischen und technischen Weiterentwicklung sowie des Betriebs dieser Systeme. Der in diesem Beitrag beschriebene Ansatz - die Landkarte - basiert auf einem Informationsmodell zur umfassenden Modellierung serviceorientierter Architekturen. Entsprechend einer Landkarte nutzt das Rahmenwerk die Modellinformationen zur Laufzeit und dient verschiedenen Zielgruppen oder Systemen als Orientierungs- und Entscheidungshilfe. Neben der geeigneten Darstellung und Bewertung der relevanten Informationen über die Systemlandschaft unterstützt die Landkarte darüber hinaus den Betrieb serviceorientierter Architekturen, indem sie die einzelnen Systembestandteile gemäß ihrer spezifizierten Soll-Konfigurationen überwacht.

Among the various aspects of Web applications that are subject to modeling, like navigation, interaction or business processes, the architectural aspect is receiving growing attention. This is related to the fact that the Web is increasingly used as a platform for distributed services which transcend organizational boundaries to form so-called federated applications. In this context, we use the term "architecture" to denote the composition of the overall solution into individual Web applications and Web services that belong to different parties and invoke each other. The design and evolution of such systems calls for models that give an overview of the federation structure and reflect the technical details of the various accesses. We introduce the WebComposition Architecture Model (WAM) as an overall modeling approach tailored to aspects of highly distributed systems with federation as an integral factor.

Today, the Web is increasingly used as a platform for distributed services, which transcend organizational boundaries to form federated applications. Consequently, there is a growing interest in the architectural aspect of Web-based systems, i.e. the composition of the overall solution into individual Web applications and Web services from different parties. The design and evolution of federated systems calls for models that give an overview of the structural as well as trust-specific composition and reflect the technical details of the various accesses. We introduce the WebComposition Architecture Model (WAM) as an overall modeling approach tailored to aspects of highly distributed systems with federation as an integral factor.