/*
* $Header: /home/pgearon/cvs/mulgara/mulgara-1.1/src/jar/client-jrdf/java/org/mulgara/client/jrdf/util/ClientGraphUtil.java,v 1.8 2005/01/05 04:57:37 newmana Exp $
* $Revision: 1.8 $
* $Date: 2005/01/05 04:57:37 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2003, 2004 The JRDF Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* the JRDF Project (http://jrdf.sf.net/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The JRDF Project" and "JRDF" must not be used to endorse
* or promote products derived from this software without prior written
* permission. For written permission, please contact
* newmana@users.sourceforge.net.
*
* 5. Products derived from this software may not be called "JRDF"
* nor may "JRDF" appear in their names without prior written
* permission of the JRDF Project.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the JRDF Project. For more
* information on JRDF, please see <http://jrdf.sourceforge.net/>.
*/
package org.mulgara.client.jrdf.util;
//local packages
import org.jrdf.graph.*;
import org.jrdf.util.ClosableIterator;
import org.mulgara.client.jrdf.*;
/**
* Utility class used with client-side JRDF Graphs.</p>
*
* <p>Data Access Object (DAO).</p>
*
* @created 2004-08-16
*
* @author <a href="mailto:robert.turner@tucanatech.com">Robert Turner</a>
*
* @version $Revision: 1.8 $
*
* @modified $Date: 2005/01/05 04:57:37 $
*
* @maintenanceAuthor $Author: newmana $
*
* @company <A href="mailto:info@PIsoftware.com">Plugged In Software</A>
*
* @copyright ©2001 <a href="http://www.pisoftware.com/">Plugged In
* Software Pty Ltd</a>
*
* @licence <a href="{@docRoot}/../../LICENCE">Mozilla Public License v1.1</a>
*/
public abstract class ClientGraphUtil {
/**
* Returns a ClosableIterator that orders the Triples by SubjectNode.
* ClosableIterator returned will be memory bound.
*
* @return ClosableIterator
* @throws GraphException
*/
public static ClosableIterator<Triple> orderBySubject(ClosableIterator<Triple> iterator) throws
GraphException {
//validate
if (iterator == null) {
throw new IllegalArgumentException("ClosableIterator cannot be null.");
}
//Get all Triples
VirtualClosableIteratorProxy<Triple> allTriplesProxy = new
DefaultClosableIteratorProxy<Triple>(iterator);
//Order the Triples
return new OrderedClosableIteratorProxy<Triple>(allTriplesProxy,
new SubjectNodeComparator());
}
/**
* Returns a ClosableIterator that orders the Triples by SubjectNode,
* PredicateNode and ObjectNode respectively. ClosableIterator returned will
* be memory bound.
*
* @return ClosableIterator
* @throws GraphException
*/
public static ClosableIterator<Triple> orderBySPO(ClosableIterator<Triple> iterator) throws
GraphException {
//validate
if (iterator == null) {
throw new IllegalArgumentException("ClosableIterator cannot be null.");
}
//wrap the iterator
VirtualClosableIteratorProxy<Triple> allTriplesProxy = new
DefaultClosableIteratorProxy<Triple>(iterator);
//Order the Triples
return new OrderedClosableIteratorProxy<Triple>(allTriplesProxy, new SPOComparator());
}
/**
* Returns a ClosableIterator that iterates over all unique subjects in the
* Graph.
*
* @param graph Graph
* @return ClosableIterator
* @throws GraphException
*/
public static ClosableIterator<Triple> getUniqueSubjects(Graph graph) throws
GraphException {
//validate
if (graph == null) {
throw new IllegalArgumentException("Graph cannot be null.");
}
//Get all Triples
ClosableIterator<Triple> allTriples = graph.find(null, null, null);
//Order the Triples
OrderedClosableIteratorProxy<Triple> orderedTriples = (OrderedClosableIteratorProxy<Triple>)
orderBySubject(allTriples);
//return an UniqueSubjectIterator.
return new UniqueSubjectIterator(orderedTriples);
}
}