ijdickinson/ImportTDBModelsExample.java

## ImportTDBModelsExample.java
package example;


import java.io.File;
import java.io.StringReader;

import org.openjena.atlas.lib.NotImplemented;

import com.hp.hpl.jena.ontology.OntModel;
import com.hp.hpl.jena.ontology.OntModelSpec;
import com.hp.hpl.jena.query.Dataset;
import com.hp.hpl.jena.rdf.model.*;
import com.hp.hpl.jena.tdb.TDB;
import com.hp.hpl.jena.tdb.TDBFactory;
import com.hp.hpl.jena.vocabulary.*;

/**
 * <p>This Jena example re-uses named graphs stored in a TDB model
 * as the imports in an ontology.</p>
 *
 * @author Ian Dickinson, Epimorphics (mailto:ian@epimorphics.com)
 */
public class ImportTDBModelsExample
{
    /***********************************/
    /* Constants                       */
    /***********************************/

    public static String ONT1 = "http://example.org/test#ont1";
    public static String ONT2 = "http://example.org/test#ont2";

    // the model we're going to load, which imports ont1 and ont2
    public static String SOURCE =
            "@prefix rdf:                <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .\n" +
            "@prefix rdfs:               <http://www.w3.org/2000/01/rdf-schema#> .\n" +
            "@prefix owl:                <http://www.w3.org/2002/07/owl#> .\n" +
            "<http://example.org/test#upper> a owl:Ontology ;\n" +
            " owl:imports <" + ONT1 + "> ;\n" +
            " owl:imports <" + ONT2 + "> .\n";

    /***********************************/
    /* Static variables                */
    /***********************************/

    /***********************************/
    /* Instance variables              */
    /***********************************/

    /***********************************/
    /* Constructors                    */
    /***********************************/

    /***********************************/
    /* External signature methods      */
    /***********************************/

    public static void main( String[] args ) {
        new ImportTDBModelsExample().run();
    }

    public void run() {
        Dataset ds = initialiseTDB();
        loadTDBContent( ds );
        OntModel m = loadImportingOntology( ds.getDefaultModel(), ds );
        m.writeAll( System.out, "Turtle", null );
    }

    /***********************************/
    /* Internal implementation methods */
    /***********************************/

    /**
     * Initialise the local TDB image if necessary.
     */
    protected Dataset initialiseTDB() {
        String tdbPath = "./target/data/tdb";
        new File( tdbPath ).mkdirs();
        return TDBFactory.createDataset( tdbPath );
    }

    /**
     * Load some test content into TDB, unless it has already been initialized.
     * @param ds
     */
    protected void loadTDBContent( Dataset ds ) {
        if (!ds.containsNamedModel( ONT1 )) {
            loadExampleGraph( ONT1, ds, "The Dread Pirate Roberts" );
            loadExampleGraph( ONT2, ds, "Chewbacca" );
        }
    }

    /**
     * Create a graph with the given name in the dataset, and initialise it with
     * some fake content (namely an owl:Ontology resource). This is a proxy for
     * loading a real ontology into the model.
     *
     * @param graphName
     * @param ds
     * @param creator
     */
    protected void loadExampleGraph( String graphName, Dataset ds, String creator ) {
        Model m = ModelFactory.createDefaultModel();

        m.createResource( graphName )
         .addProperty( RDF.type, OWL.Ontology)
         .addProperty( DCTerms.creator, creator );

        ds.addNamedModel( graphName, m );
        TDB.sync( m );
    }

    /**
     * Now we create an ontology model that imports ont1 and ont2, but arrange
     * that these are obtained from the TDB image.
     *
     * @param base
     */
    protected OntModel loadImportingOntology( Model base, Dataset ds ) {
        // this is a test, so empty the base first just to be sure
        base.removeAll();

        OntModelSpec spec = new OntModelSpec( OntModelSpec.OWL_MEM );
        spec.setImportModelGetter( new LocalTDBModelGetter( ds ) );

        OntModel om = ModelFactory.createOntologyModel( spec, base );

        // now read the source model
        StringReader in = new StringReader( SOURCE );
        om.read( in, null, "Turtle" );

        return om;
    }

    /***********************************/
    /* Inner class definitions         */
    /***********************************/

    /**
     * <p>A type of model getter that loads models from a local TDB instance,
     * if they exist as named graphs using the model URI as the graph name.</p>
     */
    static class LocalTDBModelGetter implements ModelGetter {

        private Dataset ds;

        public LocalTDBModelGetter( Dataset dataset ) {
            ds = dataset;
        }

        @Override
        public Model getModel( String uri ) {
            throw new NotImplemented( "getModel( String  ) is not implemented" );
        }

        @Override
        public Model getModel( String uri, ModelReader loadIfAbsent ) {
            Model m = ds.getNamedModel( uri );

            // create the model if necessary. In actual fact, this example code
            // will not exercise this code path, since we pre-define the models
            // we want to see in TDB
            if (m == null) {
                m = ModelFactory.createDefaultModel();
                loadIfAbsent.readModel( m, uri );
                ds.addNamedModel( uri, m );
            }

            return m;
        }
    } // LocalTDBModelGetter
}
	package example;


	import java.io.File;
	import java.io.StringReader;

	import org.openjena.atlas.lib.NotImplemented;

	import com.hp.hpl.jena.ontology.OntModel;
	import com.hp.hpl.jena.ontology.OntModelSpec;
	import com.hp.hpl.jena.query.Dataset;
	import com.hp.hpl.jena.rdf.model.*;
	import com.hp.hpl.jena.tdb.TDB;
	import com.hp.hpl.jena.tdb.TDBFactory;
	import com.hp.hpl.jena.vocabulary.*;

	/**
	* <p>This Jena example re-uses named graphs stored in a TDB model
	* as the imports in an ontology.</p>
	*
	* @author Ian Dickinson, Epimorphics (mailto:ian@epimorphics.com)
	*/
	public class ImportTDBModelsExample
	{
	/***********************************/
	/* Constants */
	/***********************************/

	public static String ONT1 = "http://example.org/test#ont1";
	public static String ONT2 = "http://example.org/test#ont2";

	// the model we're going to load, which imports ont1 and ont2
	public static String SOURCE =
	"@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .\n" +
	"@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .\n" +
	"@prefix owl: <http://www.w3.org/2002/07/owl#> .\n" +
	"<http://example.org/test#upper> a owl:Ontology ;\n" +
	" owl:imports <" + ONT1 + "> ;\n" +
	" owl:imports <" + ONT2 + "> .\n";

	/***********************************/
	/* Static variables */
	/***********************************/

	/***********************************/
	/* Instance variables */
	/***********************************/

	/***********************************/
	/* Constructors */
	/***********************************/

	/***********************************/
	/* External signature methods */
	/***********************************/

	public static void main( String[] args ) {
	new ImportTDBModelsExample().run();
	}

	public void run() {
	Dataset ds = initialiseTDB();
	loadTDBContent( ds );
	OntModel m = loadImportingOntology( ds.getDefaultModel(), ds );
	m.writeAll( System.out, "Turtle", null );
	}

	/***********************************/
	/* Internal implementation methods */
	/***********************************/

	/**
	* Initialise the local TDB image if necessary.
	*/
	protected Dataset initialiseTDB() {
	String tdbPath = "./target/data/tdb";
	new File( tdbPath ).mkdirs();
	return TDBFactory.createDataset( tdbPath );
	}

	/**
	* Load some test content into TDB, unless it has already been initialized.
	* @param ds
	*/
	protected void loadTDBContent( Dataset ds ) {
	if (!ds.containsNamedModel( ONT1 )) {
	loadExampleGraph( ONT1, ds, "The Dread Pirate Roberts" );
	loadExampleGraph( ONT2, ds, "Chewbacca" );
	}
	}

	/**
	* Create a graph with the given name in the dataset, and initialise it with
	* some fake content (namely an owl:Ontology resource). This is a proxy for
	* loading a real ontology into the model.
	*
	* @param graphName
	* @param ds
	* @param creator
	*/
	protected void loadExampleGraph( String graphName, Dataset ds, String creator ) {
	Model m = ModelFactory.createDefaultModel();

	m.createResource( graphName )
	.addProperty( RDF.type, OWL.Ontology)
	.addProperty( DCTerms.creator, creator );

	ds.addNamedModel( graphName, m );
	TDB.sync( m );
	}

	/**
	* Now we create an ontology model that imports ont1 and ont2, but arrange
	* that these are obtained from the TDB image.
	*
	* @param base
	*/
	protected OntModel loadImportingOntology( Model base, Dataset ds ) {
	// this is a test, so empty the base first just to be sure
	base.removeAll();

	OntModelSpec spec = new OntModelSpec( OntModelSpec.OWL_MEM );
	spec.setImportModelGetter( new LocalTDBModelGetter( ds ) );

	OntModel om = ModelFactory.createOntologyModel( spec, base );

	// now read the source model
	StringReader in = new StringReader( SOURCE );
	om.read( in, null, "Turtle" );

	return om;
	}

	/***********************************/
	/* Inner class definitions */
	/***********************************/

	/**
	* <p>A type of model getter that loads models from a local TDB instance,
	* if they exist as named graphs using the model URI as the graph name.</p>
	*/
	static class LocalTDBModelGetter implements ModelGetter {

	private Dataset ds;

	public LocalTDBModelGetter( Dataset dataset ) {
	ds = dataset;
	}

	@Override
	public Model getModel( String uri ) {
	throw new NotImplemented( "getModel( String ) is not implemented" );
	}

	@Override
	public Model getModel( String uri, ModelReader loadIfAbsent ) {
	Model m = ds.getNamedModel( uri );

	// create the model if necessary. In actual fact, this example code
	// will not exercise this code path, since we pre-define the models
	// we want to see in TDB
	if (m == null) {
	m = ModelFactory.createDefaultModel();
	loadIfAbsent.readModel( m, uri );
	ds.addNamedModel( uri, m );
	}

	return m;
	}
	} // LocalTDBModelGetter
	}