Diploma Theses


Web-based Application Integration according to REST-principles
(PDF, deutsch, 1,6 MB) 		This paper introduces the basic principles of RESTful Web-Services and demonstrates their conception and implementation. The basis of RESTful Web-Services is made up of the architectural principles of the World Wide Web, such as resource orientation and stateless communication. They are implemented based exclusively on Web Standards such as HTTP, URI and XML and do not require the introduction of an additional layer of protocoll.
Initially, a universal launch takes place in which the development, central properties and application errors in Web Services are described. RESTful Web-Services are then introduced, whose basic principles are formed by the Representational State Transfer (REST) style of architecture. Based on these principles, RESTful Web-Services are designed for an existing Java application. The Restlet-Framework, which reproduces the REST-Terminology in Java-categories and produces a lightweight alternative to the Servlet-technology, is evaluated for the implementation of the designed gateway.
After the description of the implementation of the drafted Web-services, a final assessment of the realised gateway in comparison to classical RPC-based SOAP Web-Services takes place.
Spring and OSGi: Analysis of the lightweight components Platform with regard to its application in service-orientated Enterprise Applications
(PDF, deutsch, 1,9 MB) 		This paper deals with the server-side integration of the dynamic, service-orientated component platform OSGi as well as its amalgamation with the flexible, object-orientated applications-framework Spring, as an efficient base for modern JavaEE-Systems.
First the core technologies of OSGi and Spring are briefly introduced, examined with regard to their most innovative concepts and classified in a comprehensive programming model by means of the subsumed characteristics of service and component orientation. Then the motivation for a combination of the technologies is highlighted and the current condition of development is presented from this perspective. An architectural examination introduces the serverside OSGi infrastructure of the Rich Server Platform (RSP) as an evolutionary stage and provides the foundation stone for the discussion of the potential structuring possibilities of Enterprise applications.
In order to strengthen the theoretical knowledge, a real active system was ported onto the RSP environment in the course of an optimistic "Proof of Concept". The challenges that needed to be resolved in the process and the necessary extentions of the prototype infrastructure extracted were separated in a detailed examination, theoretically explained and adhered to within abstract concepts or recommended courses of action for future development work. As an overall result, a fully functioning RSP platform, which is based on Servlet containers such as Tomcat or Jetty, was achieved, the active system on service and component orientated aspects was augmented, a multitude of typical Enterprise-frameworks such as Hibernate, Tapestry or Hivemind were made RSP executable and an adjusted Build-support for Mayen2 was realised.
Rich Server Environment: Analysis, design and implementation of component- and service-oriented web applications based upon the Eclipse infrastructure
(PDF, deutsch, 3,1 MB) 		This thesis aims to introduce to the modern way of programming dynamically updateable, service-oriented server applications, totally based on software components.
In the first section the importance of software components and services for this work is emphasized. Following this, the service-oriented component framework OSGi is described. A slightly extended version of this framework is implemented as the runtime of the very popular open source java IDE (integrated development environment) Eclipse, and it is also the core of the rich client architecture. A rich client is a multi-platform, extensible client, which provides the user with a rich user experience on top of a robust, dynamic component model with an additional, flexible update mechanism.
These functional features of a rich client can help to develop server applications based on an equivalent server-side environment, the so-called rich server environment. Several server-side software architectures based on the OSGi runtime are discussed and analyzed in detail. The company that suggested the topic to this thesis formulates requirements, which have to be taken into consideration when chosing the best suited architecture. It has to serve as the plattform of a component-based web application. Prior to running in a real-world server environment, some modifications have to be done, which are thoroughly explained.
In conclusion, as a proof of concept, a practical introduction into developing a component-based web application is made. On top of the previous work from the Eclipse community, a simple scenario demonstrates the practical value of dynamic server-side applications.