podd.util.iterator.CloseableOWLAxiomIterator.java Source code

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Here is the source code for podd.util.iterator.CloseableOWLAxiomIterator.java

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/*
 * Copyright (c) 2009 - 2010. School of Information Technology and Electrical
 * Engineering, The University of Queensland.  This software is being developed
 * for the "Phenomics Ontoogy Driven Data Management Project (PODD)" project.
 * PODD is a National e-Research Architecture Taskforce (NeAT) project
 * co-funded by ANDS and ARCS.
 *
 * PODD is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * PODD is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with PODD.  If not, see <http://www.gnu.org/licenses/>.
 */

package podd.util.iterator;

import info.aduna.collections.iterators.CloseableIterator;
import org.apache.commons.collections.set.UnmodifiableSet;
import org.semanticweb.owl.model.OWLAxiom;
import org.semanticweb.owl.model.OWLObject;

import java.net.URI;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Set;

/**
 * @author Yuan-Fang Li
 * @version $Id$
 */

public abstract class CloseableOWLAxiomIterator<T extends OWLAxiom> extends ImmutableIterator<T>
        implements CloseableIterator<T>, ResettableIterator<T> {

    protected final Set<T> axiomSet;
    protected final URI property;
    protected final OWLObject object;

    protected Iterator<T> iterator;
    protected T currentAxiom;

    public CloseableOWLAxiomIterator(Set<T> axiomSet, URI property, OWLObject object) {
        this.axiomSet = axiomSet;
        this.property = property;
        this.object = object;
        this.iterator = axiomSet.iterator();
        currentAxiom = null;
        getNextMatch();
    }

    private void getNextMatch() {
        while (iterator.hasNext()) {
            final T axiom = iterator.next();
            final URI currentURI = getPropertyURI(axiom);
            if ((null == property && null == object) || (null == property && getObject(axiom).equals(object))
                    || (null == object && currentURI.equals(property))
                    || (currentURI.equals(property) && getObject(axiom).equals(object))) {
                currentAxiom = axiom;
                return;
            }
        }
        currentAxiom = null;
    }

    protected abstract URI getPropertyURI(T axiom);

    protected abstract OWLObject getObject(T axiom);

    @Override
    public boolean hasNext() {
        return (null != currentAxiom);
    }

    @Override
    public T next() {
        if (hasNext()) {
            T axiom = currentAxiom;
            getNextMatch();
            return axiom;
        } else {
            throw new NoSuchElementException("No more element in the iterator.");
        }
    }

    @Override
    public void close() {
        if (axiomSet instanceof UnmodifiableSet) {
            axiomSet.clear();
        }
    }

    @Override
    public void reset() {
        iterator = axiomSet.iterator();
    }
}