Entwicklung eines grafischen Query Builders für verteilte SPARQL-Abfragen

For the Semantic Web integration and query engine middleware SemWIQ, a web-based graphical query builder is developed. To provide this, a graphical environment for modelling semantic queries on the basis of the W3C-SPARQL-Spezification is needed. In this thesis, SPARUI, a Software-prototype for this application area is described. Classes and connections of Ontology representations (in OWL Syntax) are graphically described and used to model a query. Subsequently, for further processing, these visualized queries are translated into SPARQL. Through use of the Google web toolkit framework, a Java-to-JavaScript-compiler, a purely JavaScript based client is developed. This therefore enabled a simple interaction with existing systems and applications. In addition, the entire development of the client could be realized within Java. On the basis of the developed prototype, it is shown how users without distinct knowledge about SPARQL can generate and manipulate queries. In the course of the prototype development, the different possibilities of visualized query formulation are examined and mutually compared.