Reasoner Implementations

The OWL API includes various interfaces for accessing OWL reasoners. In order to access a reasoner via the API a reasoner implementation is needed. There are currently two reasoner implementations available Pellet and FaCT++. To use either of these reasoners you must download the appropriate libraries and place them in your class path.

Using Pellet

  • Download the Pellet libraries from http://pellet.owldl.com/download
  • Unzip the zip archive and place all jars in your classpath. Note that Pellet comes as a set of jars and a set of needed libraries; if any is missing, you will likely get a ClassDefNotFound error.
  • You can instantiate Pellet in the following way:
    OWLReasoner reasoner = new PelletReasonerFactory().createReasoner(ontology);

Using FaCT++

  • Go to the FaCT++ downloads page at Google Code
  • Download the FaCT++ OWLAPI (with Java API included) jar. Download the appropriate FaCT++ precompiled binaries for your platform (OS X, Linux or Windows).
  • Place the FaCT++OWLAPI-vx.x.x.jar file in your class path (along with the OWL API jar files).
  • Unzip the native libraries and ensure that the directory containing the FaCTPlusPlusJNI library [1] is in your java.library.path. For example if the libraries reside in C:\Windows\temp then you should add:
    -Djava.library.path=C:\Windows\temp
    to the arguments for your Java application.
  • You can instatiate FaCT++ in the following way:
    OWLReasoner reasoner = new FaCTPlusPlusReasonerFactory().createReasoner(ontology);