WEB service interfaces for inter-organisational business processes an infrastructure for automated reconciliation

For the majority of front-end e-business systems, the assumption of a coherent and homogeneous set of interfaces is highly unrealistic. Problems start in the back-end, with systems characterised by a heterogeneous mix of applications and business processes. Integration can be complex and expensive, as systems evolve more in accordance with business needs than with technical architectures. E-business systems are faced with the challenge to give a coherent image of a diversified reality. Web services make business interfaces more efficient, but effectiveness is a business requirement of at least comparable importance. We propose a technique for automatic reconciliation of the Web service interfaces involved in inter-organisational business processes. The working assumption is that the Web service front-end of each company is represented by a set of WSDL and WSCL interfaces. The result of our reconciliation method is a common interface that all the parties can effectively enforce. Indications are also given on ways to adapt individual interfaces to the common one. The technique was embodied in a prototype that we also present

Safer typing of complex API usage through Java generics

When several incompatible implementations of a single API are in use in a Java program, the danger exists that instances from different implementations may inadvertently be mixed, leading to errors. In this paper we show how to use generics to prevent such mixing. The core idea of the approach is to add a type parameter to the interfaces of the API, and tie the classes that make up an implementation to a unique choice of type parameter. In this way methods of the API can only be invoked with arguments that belong to the same implementation. We show that the presence of a type parameter in the interfaces does not violate the principle of interface-based programming: clients can still completely abstract over the choice of implementation. In addition, we demonstrate how code can be reused between different implementations, how implementations can be defined as extensions of other implementations, and how different implementations may be mixed in a controlled and safe manner. To explore the feasibility of the approach, gauge its usability, and identify any issues that may crop up in practical usage, we have refactored a fairly large existing API-based application suite, and we report on the experience gained in the process

Blue - A Language for Teaching Object-Oriented Programming

Teaching object-oriented programming has clearly become an important part of computer science education. We agree with many others that the best place to teach it is in the CS1 introductory course. Many problems with this have been reported in the literature. These mainly result from inadequate languages and environments. Blue is a new language and integrated programming environment, currently under development explicitly for object-oriented teaching. We expect clear advantages from the use of Blue for first year teaching compared to using other available languages. This paper describes the design principles on which the language was based and the most important aspects of the language itself

Managed Forgetting to Support Information Management and Knowledge Work

Trends like digital transformation even intensify the already overwhelming mass of information knowledge workers face in their daily life. To counter this, we have been investigating knowledge work and information management support measures inspired by human forgetting. In this paper, we give an overview of solutions we have found during the last five years as well as challenges that still need to be tackled. Additionally, we share experiences gained with the prototype of a first forgetful information system used 24/7 in our daily work for the last three years. We also address the untapped potential of more explicated user context as well as features inspired by Memory Inhibition, which is our current focus of research.Comment: 10 pages, 2 figures, preprint, final version to appear in KI - K\"unstliche Intelligenz, Special Issue: Intentional Forgettin

Integrating the common variability language with multilanguage annotations for web engineering

Web applications development involves managing a high diversity of files and resources like code, pages or style sheets, implemented in different languages. To deal with the automatic generation of custom-made configurations of web applications, industry usually adopts annotation-based approaches even though the majority of studies encourage the use of composition-based approaches to implement Software Product Lines. Recent work tries to combine both approaches to get the complementary benefits. However, technological companies are reticent to adopt new development paradigms such as feature-oriented programming or aspect-oriented programming. Moreover, it is extremely difficult, or even impossible, to apply these programming models to web applications, mainly because of their multilingual nature, since their development involves multiple types of source code (Java, Groovy, JavaScript), templates (HTML, Markdown, XML), style sheet files (CSS and its variants, such as SCSS), and other files (JSON, YML, shell scripts). We propose to use the Common Variability Language as a composition-based approach and integrate annotations to manage fine grained variability of a Software Product Line for web applications. In this paper, we (i) show that existing composition and annotation-based approaches, including some well-known combinations, are not appropriate to model and implement the variability of web applications; and (ii) present a combined approach that effectively integrates annotations into a composition-based approach for web applications. We implement our approach and show its applicability with an industrial real-world system.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech