[Fwd: RDF2Go 3.1 released - A wrapper over Java triple stores]

From: Stefano Mazzocchi <stefanom_at_mit.edu>
Date: Thu, 09 Mar 2006 09:13:54 -0800

Came across RDF2Go today, basically a JDBC-like layer for RDF triple
stores in java, which would allow us to be triple-store neutral and
allow easier performance testing across various containers.

Has anybody tried it? Are there severe performance drawbacks?

Thanks in advance.

Stefano Mazzocchi
Research Scientist                 Digital Libraries Research Group
Massachusetts Institute of Technology            location: E25-131C
77 Massachusetts Ave                   telephone: +1 (617) 253-1096
Cambridge, MA  02139-4307              email: stefanom at mit . edu

attached mail follows:


  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.

  - 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
    - 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].

    [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

  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
voelkel_at_fzi.de   +49 721 9654-854   www.xam.de
Workshop  on  Semantic  Wikis:  http://semwiki.org  -  Deadline Extended!
Received on Thu Mar 09 2006 - 17:13:58 EST

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