RDFRelationshipReader.java

/* The contents of this file are subject to the license and copyright terms
 * detailed in the license directory at the root of the source tree (also
 * available online at http://fedora-commons.org/license/).
 */
package org.fcrepo.server.storage;

import java.io.InputStream;
import java.util.Collections;
import java.util.Set;

import org.fcrepo.server.errors.GeneralException;
import org.fcrepo.server.errors.ServerException;
import org.fcrepo.server.storage.types.Datastream;
import org.fcrepo.server.storage.types.RelationshipTuple;
import org.jrdf.graph.Triple;
import org.trippi.RDFFormat;
import org.trippi.TrippiException;
import org.trippi.io.TripleIteratorFactory;
import org.trippi.io.transform.impl.Identity;


public abstract class RDFRelationshipReader {

    public static Set<RelationshipTuple> readRelationships(Datastream ds)
            throws ServerException {

        if (ds == null) {
            return Collections.emptySet();
        }

        try {
            return readRelationships(ds.getContentStream());
        } catch (TrippiException e) {
            throw new GeneralException(e.getMessage(), e);
        }
    }

    public static Set<RelationshipTuple> readRelationships(InputStream dsContent)
            throws TrippiException {

        return TripleIteratorFactory.defaultInstance().allAsSet(dsContent, null,
                        RDFFormat.RDF_XML, RelationshipTuple.TRANSFORMER);
    }
    
    public static Set<Triple> readTriples(InputStream dsContent)
            throws TrippiException {
        return TripleIteratorFactory.defaultInstance().allAsSet(dsContent, null,
                RDFFormat.RDF_XML, Identity.instance);
    }
}