/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.clerezza.rdf.jena.facade;
import com.hp.hpl.jena.graph.Graph;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.Reifier;
import com.hp.hpl.jena.graph.Triple;
import com.hp.hpl.jena.graph.TripleMatch;
import com.hp.hpl.jena.rdf.model.impl.NodeIteratorImpl;
import com.hp.hpl.jena.shared.AlreadyReifiedException;
import com.hp.hpl.jena.shared.ReificationStyle;
import com.hp.hpl.jena.util.iterator.ExtendedIterator;
import com.hp.hpl.jena.util.iterator.Filter;
import com.hp.hpl.jena.util.iterator.NullIterator;
import com.hp.hpl.jena.vocabulary.RDF;
import java.util.Iterator;
/**
* an implementation of reifier that does nothing but access the underlying
* graph to return the reifications;
*
* @author reto
*/
public class DirectReifier implements Reifier {
private Graph graph;
public DirectReifier(Graph graph) {
this.graph = graph;
}
@Override
public ExtendedIterator find(TripleMatch arg0) {
return new NullIterator();
}
@Override
public ExtendedIterator findExposed(TripleMatch arg0) {
return new NullIterator();
}
@Override
public ExtendedIterator findEither(TripleMatch arg0, boolean arg1) {
return new NullIterator();
}
@Override
public int size() {
return 0;
}
@Override
public ReificationStyle getStyle() {
return ReificationStyle.Standard;
}
@Override
public Graph getParentGraph() {
return graph;
}
@Override
public Node reifyAs(Node node, Triple t) {
if (hasTriple(node)) {
throw new AlreadyReifiedException(node);
}
graph.add(new Triple(node,RDF.subject.asNode(), t.getSubject()));
graph.add(new Triple(node,RDF.predicate.asNode(), t.getPredicate()));
graph.add(new Triple(node,RDF.object.asNode(), t.getObject()));
return node;
}
@Override
public boolean hasTriple(Node node) {
if (!graph.contains(node,RDF.subject.asNode(), null)) {
return false;
}
if (!graph.contains(node,RDF.predicate.asNode(), null)) {
return false;
}
if (!graph.contains(node,RDF.object.asNode(), null)) {
return false;
}
return false;
}
@Override
public boolean hasTriple(Triple triple) {
if (!graph.contains(null, RDF.subject.asNode(), triple.getSubject())) {
return false;
}
if (!graph.contains(null, RDF.predicate.asNode(), triple.getPredicate())) {
return false;
}
if (!graph.contains(null, RDF.object.asNode(), triple.getObject())) {
return false;
}
return false;
}
@Override
public ExtendedIterator allNodes() {
ExtendedIterator tripleIter = graph.find(null, RDF.subject.asNode(), null);
final ExtendedIterator filteredTripleIter = tripleIter.filterKeep(new Filter() {
@Override
public boolean accept(Object o) {
Triple t = (Triple) o;
return hasTriple(t.getSubject());
}
});
return new NodeIteratorImpl(new Iterator() {
@Override
public boolean hasNext() {
return filteredTripleIter.hasNext();
}
@Override
public Object next() {
return ((Triple)filteredTripleIter.next()).getSubject();
}
@Override
public void remove() {
throw new UnsupportedOperationException("Not supported yet.");
}
}, this
);
}
@Override
public ExtendedIterator allNodes(final Triple triple) {
ExtendedIterator tripleIter = graph.find(null, RDF.subject.asNode(), triple.getSubject());
final ExtendedIterator filteredTripleIter = tripleIter.filterKeep(new Filter() {
@Override
public boolean accept(Object o) {
Triple t = (Triple) o;
return graph.contains(t.getSubject(), RDF.object.asNode(), triple.getObject())
&& graph.contains(t.getSubject(), RDF.predicate.asNode(), triple.getPredicate());
}
});
return new NodeIteratorImpl(new Iterator() {
@Override
public boolean hasNext() {
return filteredTripleIter.hasNext();
}
@Override
public Object next() {
return ((Triple)filteredTripleIter.next()).getSubject();
}
@Override
public void remove() {
throw new UnsupportedOperationException("Not supported yet.");
}
}, this
);
}
@Override
public void remove(Node arg0, Triple arg1) {
}
@Override
public void remove(Triple arg0) {
}
@Override
public boolean handledAdd(Triple arg0) {
return false;
}
@Override
public boolean handledRemove(Triple arg0) {
return false;
}
@Override
public void close() {
}
@Override
public Triple getTriple(Node node) {
ExtendedIterator iter = graph.find(node, RDF.subject.asNode(), null);
if (!iter.hasNext()) {
return null;
}
Node subject = ((Triple)iter.next()).getObject();
iter = graph.find(node, RDF.predicate.asNode(), null);
if (!iter.hasNext()) {
return null;
}
Node predicate = ((Triple)iter.next()).getObject();
iter = graph.find(node, RDF.object.asNode(), null);
if (!iter.hasNext()) {
return null;
}
Node object = ((Triple)iter.next()).getObject();
return new Triple(subject, predicate, object);
}
}