/*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* The Original Code is the Kowari Metadata Store.
*
* The Initial Developer of the Original Code is Plugged In Software Pty
* Ltd (http://www.pisoftware.com, mailto:info@pisoftware.com). Portions
* created by Plugged In Software Pty Ltd are Copyright (C) 2001,2002
* Northrop Grumman Corporation. All Rights Reserved.
*
* This file is an original work and contains no Original Code. It was
* developed by Netymon Pty Ltd under contract to the Australian
* Commonwealth Government, Defense Science and Technology Organisation
* under contract #4500507038 and is contributed back to the Kowari/Mulgara
* Project as per clauses 4.1.3 and 4.1.4 of the above contract.
*
* Contributor(s): N/A.
*
* Copyright:
* The copyright on this file is held by:
* The Australian Commonwealth Government
* Department of Defense
* Developed by Netymon Pty Ltd
* Copyright (C) 2006
* The Australian Commonwealth Government
* Department of Defense
*
* [NOTE: The text of this Exhibit A may differ slightly from the text
* of the notices in the Source Code files of the Original Code. You
* should use the text of this Exhibit A rather than the text found in the
* Original Code Source Code for Your Modifications.]
*
*/
package org.mulgara.resolver.relational;
// Java 2 standard packages
import java.net.URI;
// Third party packages
import org.apache.log4j.Logger;
import org.jrdf.vocabulary.RDF;
// Locally written packages
import org.mulgara.query.rdf.Mulgara;
import org.mulgara.query.rdf.URIReferenceImpl;
import org.mulgara.resolver.spi.*;
/**
* Represents the time invariant concept of a relationally backed rdf-graph.
*
* @created 2006-04-30
*
* @author Andrae Muys
*
* @version $Revision: 1.1.1.1 $
*
* @modified $Date: 2005/10/30 19:21:14 $ @maintenanceAuthor $Author: prototypo $
*
* @company <a href="mailto:info@netymon.com">Netymon Pty Ltd</a>
*
* @copyright ©2006 Australian Commonwealth Government, Department of Defense.
* All rights reserved.
*
* @licence <a href="{@docRoot}/../../LICENCE">Mozilla Public License v1.1</a>
*/
public class RelationalResolverFactory implements ResolverFactory {
private static final Logger logger = Logger.getLogger(RelationalResolverFactory.class);
/** The preallocated local node representing the rdf:type property */
private long rdfType;
/** Node id for the relational model type */
private long relationalModelTypeNode;
/** The URL associated with the Relational Graph type. */
private static final URI modelTypeURI = URI.create(Mulgara.NAMESPACE + "RelationalModel");
/**
* The preallocated local node representing the system model and it's type(<code>#</code>).
*/
private long systemModel;
private long systemModelType;
/**
* Constructor
*
* @param initializer The initialisation object to allow us access to
* resolver initialisation parameters
*
* @throws InitializerException
*/
private RelationalResolverFactory(ResolverFactoryInitializer initializer)
throws InitializerException {
// Validate parameters
if (initializer == null) {
throw new IllegalArgumentException("Null 'initializer' parameter");
}
// Set the system model and its type
systemModel = initializer.getSystemModel();
systemModelType = initializer.getSystemModelType();
// Retrieve the rdf type predicate
rdfType = initializer.preallocate(new URIReferenceImpl(RDF.TYPE));
// Set the relational type node
relationalModelTypeNode = initializer.preallocate(new URIReferenceImpl(modelTypeURI));
// Claim mulgara:RelationalModel
initializer.addModelType(modelTypeURI, this);
if (logger.isDebugEnabled()) {
logger.debug("Registered Relational resolver to handle " + modelTypeURI);
}
// Register RelationalConstraint
initializer.registerNewConstraint(new RelationalConstraintDescriptor());
// Register the RelationalConstraint's transformation
initializer.addSymbolicTransformation(new RelationalTransformer(modelTypeURI));
}
/**
* {@inheritDoc ResolverFactory}
* noop - unless we maintain a connection pool of some description or similar trans-transactional resource.
*/
public void close() { }
/**
* {@inheritDoc ResolverFactory}
*
* noop - read-only access to relational database precludes delete.
*/
public void delete() { }
/**
* {@inheritDoc}
* @return <code>null</code> - no default graphs for this resolver
*/
public Graph[] getDefaultGraphs() { return null; }
/**
* {@inheritDoc}
* @return <code>false</code> - this graph can resolve ($s $p $o) but the resolution is
* always empty, so exporting this type graph has no meaning.
*/
public boolean supportsExport() {
return false;
}
/**
* Register this resolver upon database startup.
*
* @param initializer the database within which to find or
* create the various XML Schema resources
*
* @throws InitializerException if the XML Schema resources can't be found or
* created
*/
public static ResolverFactory newInstance(ResolverFactoryInitializer initializer)
throws InitializerException {
return new RelationalResolverFactory(initializer);
}
/**
* Obtain a Relational resolver.
*
* @param resolverSession the session which this query is local to
* @param canWrite {@inheritDoc}; ignored by this implementation
* @param systemResolver The resolver being used for the system model
*
* @throws ResolverFactoryException {@inheritDoc}
*/
public Resolver newResolver(boolean canWrite, ResolverSession resolverSession,
Resolver systemResolver)
throws ResolverFactoryException {
return new RelationalResolver(resolverSession, systemResolver, rdfType,
systemModel, systemModelType, modelTypeURI,
relationalModelTypeNode);
}
}