THE SWS MEDIATOR WITH WEBML/WEBRATIO AND

JABC/JETI: A COMPARISON

Tiziana Margaria

∗

, Christian Winkler

∗

, Christian Kubczak

†

, Bernhard Steffen

†

∗

Institute for Informatics, University of Potsdam, 14482 Potsdam, Germany,

†

Department of Computer Science, University of Dortmund, 44227 Dortmund, Germany,

Marco Brambilla

‡

, Stefano Ceri

‡

, Dario Cerizza

, Emanuele Della Valle

, Federico M. Facca

‡

, Christina Tziviskou

‡

Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milano, Italy

CEFRIEL, Milano, Italy

Keywords:

Semantic Web, Web services, jABC, WebML.

Abstract:

In this paper we compare the SWS Challenge Mediator solutions provided using the WebML/Webratio and

the jABC/jETI approaches.

1 INTRODUCTION

In this paper we compare two solutions to the medi-

ation scenario of the SWS challenge

that are based

on the use of WebML (Ceri et al., 2002) and of the

jABC (Steffen et al., 2006; jABC Website, 2007) as

modelling and execution platforms.

We compare only the solutions to the ﬁrst version

of the SWS Challenge scenario, since the jABC solu-

tion was discussed at the SWS review workshop only

for this ﬁrst Phase. Nevertheless, the technical com-

parison of the approaches is of general interest and

valid also for the second phase of the scenario.

Both groups adopt a model based approach, sup-

ported by model driven design tools and environ-

ments. This allows modelling the mediator in a graph-

ical high level modelling language and supports the

derivation of an executable mediator from these mod-

els. The solutions are thus similar in their spirit, and

we provide here a ﬁrst description and comparison of

the similarities and differences, at the modelling, lan-

guage, tool, and change management levels.

In the following, we brieﬂy describe the two con-

crete solutions (Sect. 2 and 3) from the point of view

of the used technologies, then we sketch a comparison

(Sect. 4), we present a reduction of the two solutions

to their mere, common essence (Sect. 5), and ﬁnally

we conclude in Sect. 6.

http://sws-challenge.org

2 WEBML

The speciﬁcation of a WebML application (Ceri et al.,

2002) consists of a set of models: the application data

model (an extended Entity-Relationship model), one

or more hypertext models (i.e., different site views

or different service views), expressing the navigation

paths and the page composition of the Web applica-

tion or the chain of operations needed to describe a

Web service; the presentation model, describing the

visual aspects of the pages for user views. WebML

covers also the development of B2B Web applica-

tions implementing business processes, thereby sup-

porting full-ﬂedged collaborative workﬂow-based ap-

plications, spanning multiple individuals, services,

and organizations. In such case the service view or

site view is partially generated by a BPMN model

representing the workﬂows involved in the applica-

tion. The core elements of a WebML diagram are

units. Each WebML unit has its own well deﬁned

semantic and its execution complies with its seman-

tic. The composition of different units leads to the

description of the semantic of hypertext or Web ser-

vices. WebML provides standard units for querying

data (e.g. Index unit, Selector unit), modifying

data (e.g. Modifying unit). The WebML conceptual

model has been also extended with a service model

that includes a set of Web service units (Manolescu

et al., 2005), corresponding to the WSDL classes of

422

Margaria T., Winkler C., Kubczak C., Steffen B., Brambilla M., Ceri S., Cerizza D., Della Valle E., M. Facca F. and Tziviskou C. (2007).

THE SWS MEDIATOR WITH WEBML/WEBRATIO AND JABC/JETI: A COMPARISON.

In Proceedings of the Ninth International Conference on Enterprise Information Systems, pages 422-429

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