- From: Max Völkel <voelkel@fzi.de>
- Date: Thu, 9 Mar 2006 17:51:43 +0100
- To: semantic-web <semantic-web@w3.org>, semanticweb@yahoogroups.com
Hi, today we released [1] a new version of RDF2Go [2], a simple wrapper over Java triple stores, similar in spirit of Jakarta Commons Logging. It allows developers to un-tangle their semantic web applications from a specific store and thus profit from using always the best store (performance, features). RDF2Go currently comes with adaptors for: ---------------------------------------- - Jena 2.2 (bug with arbitrary non-XSD datatypes in literals) - Jena 2.3 - Sesame 1 (has no SPARQL support) - Sesame 2 (bug in Sesame2: Context URL cannot be retrieved. Queries don't work yet.) - YARS (language tagged literals bug, YARS adapter currenlty refactored by YARS developer Andreas Harth. SPAQRL not supported.) - NG4J (no SPARQL support in adaptor, TRIQ available) - JCR (with JackRabbit) All adaptors incl. all needed libraries can be downloaded from [1]. Writing new adaptors is easy, only 6 methods have to be implemented. Features: -------- - add and remove triples with one-method-call (this is almost like the patented one-click-shopping) - query for triple patterns - SPARQL (not all stores support it) - full support for quad stores - built-in URIs for RDF, RDFS, XSD - NO support for parsing: use the supplied parser from the triple stores instead. We don't re-implement everyhing. RDF2Go maps RDF to Java as follows: ---------------------------------- uri - java.net.URI blank node - org.ontoware.rdf2go.BlankNode plain literal - java.lang.String language tagged literal - org.ontoware.rdf2go.LanguageTagLiteral datatyped literal - org.ontoware.rdf2go.LanguageTagLiteral This allows to add statements as simple as // assume some URIs have been created URI mike = new URI("urn://mike"); URI foafName = new URI("http://foaf.com#name"); // add triple model.addStatement( mike, foafName, "Mike Müller" ); Further Information ------------------- - More about the workflow using RDF2Go can be found at [2]. - A paper describing RDF2Go in brief can be found at [3] (skip other sections). - There are a number of related approaches, but to our knowledge none is a simplistic and comes with such a large number of adapters. Related approaches are KPOntology [4], Trippi [5] and of course the inventor of all these [6]. References ---------- [1] http://ontoware.org/frs/?group_id=37&release_id=173 [2] http://rdf2go.ontoware.org [3] http://m3pe.org/seminar/voelkel.pdf [4] http://kpontology.isoco.com/download.html [5] http://trippi.sourceforge.net/ [6] http://www-db.stanford.edu/~melnik/rdf/api.html Gimmick ------- The first person who emails me and wants to write an adaptor for another triple (or quad) store gets my immediate personal support ;-) Kind regards, Max Völkel -- Dipl.-Inform. Max Völkel, Universität Karlsruhe / FZI http://nepomuk.semanticdesktop.org voelkel@fzi.de +49 721 9654-854 www.xam.de Workshop on Semantic Wikis: http://semwiki.org - Deadline Extended!
Received on Thursday, 9 March 2006 16:52:26 UTC