RDF2Go

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RDF2Go
Logo of RDF2Go
rdf2go.semweb4j.org/
Status: stable
Last release: 4.8.3 (2013/06/04)
License: BSD
Affiliation: FZI

RDF2Go is an abstraction over triple (and quad) stores. It allows developers to program against rdf2go interfaces and choose or change the implementation later easily.

Contents

About

The three main features of RDF2Go are:

  • Program now, decide on triple store later - triple-centric API
  • Easy to extend - only a few simple methods have to be implemented by a triple (or quad) store
  • Triple and quad support - All techniques are available for triple and quad models

RDF2GO is released under the new BSD license. Alternative licensing is possible, just ask us. The project is funded by the European projects Knowledge Web, NEPOMUK and PLAY.

Download and Maven access

  • Download releases from directory
    • For changelog, please consult the module-changelogs

Maven repositories for all modules:

       <repository>
           <id>semweb4j-repo</id>
           <name>Semweb4j.org maven repo</name>
           <url>http://semweb4j.org/repo/</url>
           <releases>
               <enabled>true</enabled>
           </releases>
       </repository>
       <repository>
           <id>semweb4j-snapshots</id>
           <name>Semweb4j.org maven snapshot repo</name>
           <url>http://semweb4j.org/snapshots/</url>
           <releases>
               <enabled>false</enabled>
           </releases>
           <snapshots>
               <enabled>true</enabled>
               <updatePolicy>always</updatePolicy>
               <checksumPolicy>fail</checksumPolicy>
           </snapshots>
       </repository>

Maven dependencies:

       <dependency>
           <groupId>org.semweb4j</groupId>
           <artifactId>rdf2go.api</artifactId>
           <version>4.8.3</version>
       </dependency>

For the module dependencies just look in the repository and browse to the respective pom.xml file: http://mavenrepo.fzi.de/semweb4j.org/repo/org/semweb4j/

Implementations

Jena Adapter (rdf2go.impl.jena)

Implements the API and extends the impl.base classes. Delegates all calls to a Jena 2.10.1 model. This adapter provides a Model implementation and, new also a ModelSet.

Sesame Adapter (rdf2go.impl.sesame)

Implements the API and extends the impl.base classes. Delegates all calls to a Sesame 2.7.1 repository. This adapter provides a Model and a ModelSet implementation.

  • Maven reports including links to JavaDocs, changelog, source code as HTML, JUnit test results, developer team, dependencies, list of open TODO tags in the code, ...
  • Releases (consider downloding the distribution instead)
  • Anonymous Subversion (use https:// for developer access)
  • Status: up-to date with RDF2Go 4.8.3 API

OWLIM (com.ontotext.trree.rdf2go)

Implements API and uses a BigOWLIM SAIL as part of the SemanticSpaces project.

Maven repository

<repositories>
 <repository>
  <id>sti2-archiva-external</id>
  <url>http://maven.sti2.at/archiva/repository/external</url>
 </repository>
 <repository>
  <id>sti2-archiva-snapshots</id>
  <url>http://maven.sti2.at/archiva/repository/snapshots</url>
 </repository>
</repositories>

The current release version is 0.0.2, the current development version is 0.0.3-SNAPSHOT.

<dependencies>
 <dependency>
  <groupId>eu.soa4all.semanticspaces</groupId>
  <artifactId>owlim-rdf2go</artifactId>
  <version>0.0.2</version>
 </dependency>
</dependencies>

The source code of the working version 0.0.2 including the OWLIM rdf2go adapters is now also available publicly on sourceforge.net: http://semanticspaces.svn.sourceforge.net/viewvc/semanticspaces/trunk/

Modules

RDF2Go consists of several parts that together make up the distribution. The JARs are named org.semweb4j.* and the Java packages in the JARs are still named org.ontoware.* to maintain compatibility with existing deployments.

In previous versions of RDF2Go there was a YARS adapter which is no longer maintained due to lack of time. Do you want to help out? Contact us!

Note: As of RDF2Go 4.7.0 the module structure has been simplified. Only the modules listed here are relevant. Discontinued modules are still in SVN

API (rdf2go.api)

This module contains the API (interfaces and classes) as well as base implementation classes (such as AbstractModel). The module also contains utility classes running on top of any adapter, e.g., the RDFTool class developed by DFKI.

See also

  • Maven reports including links to JavaDocs, changelog, source code as HTML, JUnit test results, developer team, dependencies, list of open TODO tags in the code, ...
  • Releases (consider downloding the distribution instead)
  • Anonymous Subversion (use https:// for developer access)

The API is stable and currently no changes to it are planned.

Distribution (rdf2go.dist)

This is a simple maven project that helps to create a complete distribution. It's mainly a pom.xml file with dependencies to other rdf2go parts.

Documentation and Tutorial

Related Projects

Road Map

For future versions suggested changes are:

  • Cleaner SPI interface (API is for users, SPI is for those people implementing the adapters)

Contact, Feedback, Help

Acknowledgements

Who uses RDF2GO?

  • RDFReactor - Object-oriented RDF access in Java, no RDF knowledge required at all (but an RDF Schema)
  • SemVersion - Versioning for RDF
  • Aperture - extracting and querying full-text content and metadata from various sources
  • Hyena - Universal RDF editor
  • NEPOMUK
  • SemFS
  • Theseus, Alexandria, in basic technologies
  • SOA4All
  • The Fascinator - eResearch publication metadata management
  • Amdatu - Open Source platform and runtime for open, service oriented and cloud aware applications
  • RDFBeans - an OO-Mapper for RDF using annotations
  • PLAY - Research project targeting processing of real-time RDF data

Are you using RDF2Go? Please add yourself to the list.

How to use RDF2Go as a Semantic Web developer

Example releases since version 4.3.x:

  public static void main(String[] args) throws ModelException {

	// getting model
	Model model = RDF2Go.getModelFactory().createModel();
        model.open();

	// creating URIs
	URI max = model.createURI("http://xam.de/foaf.rdf.xml#i");
	URI currentProject = model.createURI("http://xmlns.com/foaf/0.1/#term_currentProject");
	URI name = model.createURI("http://xmlns.com/foaf/0.1/#term_name");
	URI semweb4j = model.createURI("http://semweb4j.org");

	// adding a statement to the model
	model.addStatement(max, currentProject, semweb4j);
	model.addStatement(max, name, "Max Völkel");
		
	// dumping model to the screen
	model.dump();

        // query model for all names of max
        for(Statement stmt : model.getStatement(max,name, Variable.ANY) ) {
          // do something
        System.out.println( stmt.getObject() );
      }
 }

How to contribute to RDF2Go

It's a good idea to first announce on the list, what you want to do, to avoid duplicate work. Check out the latest trunk, make your changes and create a patch (in Eclipse: choose 'project' scope, not 'workspace'). Email the patch to Max Völkel and get it applied. Or even better: attach it to a JIRA bug tracker issue.

Related Work

Besides projects listed at Tripresso, the following projects are relevant:

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