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    <p>To list all of the instances of an OntClass, you can use one of the aptly named <a href="http://jena.apache.org/documentation/javadoc/jena/com/hp/hpl/jena/ontology/OntClass.html#listInstances%28%29" rel="nofollow"><code>OntClass.listInstances</code></a>. It's described clearly in the javadoc. In general, I'd suggest that if you're using an API, it's good practice to skim the javadoc of the class or interface that you're working with. You don't need to memorize every bit of it, but you'll have some idea of what's available and know where to look when you need something.</p> <h3>Code Sample</h3> <pre class="lang-java prettyprint-override"><code>import com.hp.hpl.jena.ontology.OntClass; import com.hp.hpl.jena.ontology.OntModel; import com.hp.hpl.jena.ontology.OntModelSpec; import com.hp.hpl.jena.ontology.OntResource; import com.hp.hpl.jena.rdf.model.ModelFactory; import com.hp.hpl.jena.util.iterator.ExtendedIterator; public class ListInstancesExample { public static void main(String[] args) { // Load the wine ontology. final OntModel model = ModelFactory.createOntologyModel( OntModelSpec.OWL_DL_MEM ); model.read( "http://www.w3.org/TR/owl-guide/wine.rdf" ); // Get the Merlot class. final OntClass merlot = model.getOntClass( "http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#Merlot" ); // Print each of its instances. for ( final ExtendedIterator&lt;? extends OntResource&gt; merlots = merlot.listInstances(); merlots.hasNext(); ) { System.out.println( merlots.next() ); } } } </code></pre> <h3>Output</h3> <pre class="lang-none prettyprint-override"><code>http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#LongridgeMerlot http://www.w3.org/TR/2003/PR-owl-guide-20031209/wine#GaryFarrellMerlot </code></pre>
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    1. USJoshua Taylor
    1. USJoshua Taylor
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    1. COOntClass basically refers to the Ontology which is delinked from the Model that contains the resources. The function does not take the Model as the argument. So how is it supposed to work? Sorry, I don't get it.
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    2. CO@user592748 An OntClass is a resource, and holds a reference to a model, yes. OntClass#listInstances is querying the OntClass's model for triples of the type (?individual,rdf:type,this). To use OntClass#listInstances, you do need a reference to the OntClass, of course. I've added a code example.
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