/*
* 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.commons;
import com.hp.hpl.jena.graph.Node;
import java.util.Map;
import org.apache.clerezza.rdf.core.BNode;
import org.apache.clerezza.rdf.core.Language;
import org.apache.clerezza.rdf.core.Literal;
import org.apache.clerezza.rdf.core.NonLiteral;
import org.apache.clerezza.rdf.core.Resource;
import org.apache.clerezza.rdf.core.Triple;
import org.apache.clerezza.rdf.core.UriRef;
import org.apache.clerezza.rdf.core.impl.PlainLiteralImpl;
import org.apache.clerezza.rdf.core.impl.TripleImpl;
import org.apache.clerezza.rdf.core.impl.TypedLiteralImpl;
/**
*
* @author rbn
*/
public class Jena2TriaUtil {
private final Map<Node, BNode> tria2JenaBNodes;
public Jena2TriaUtil(Map<Node,BNode> tria2JenaBNodes) {
this.tria2JenaBNodes = tria2JenaBNodes;
}
private BNode convertJenaNode2TriaBlankNode(Node node) {
BNode result = tria2JenaBNodes.get(node);
if (result == null) {
result = new JenaBNodeWrapper(node);
//tria2JenaBNodes.put(node,result);
}
return result;
}
/**
* Converts a jena literal within a node to a literal.
*
* @param node
* @return TypedLiteral if data type exists otherwise a PlainLiteral
*/
private Literal convertJenaLiteral2Literal(Node node) {
final String lexicalForm = node.getLiteralLexicalForm();
String datatypeString = node.getLiteralDatatypeURI();
if (datatypeString != null) {
UriRef dtUriRef = new UriRef(datatypeString);
return new TypedLiteralImpl(lexicalForm, dtUriRef);
} else {
String language = node.getLiteralLanguage();
if ((language != null) && !language.equals("")) {
return new PlainLiteralImpl(lexicalForm, new Language(language));
} else {
return new PlainLiteralImpl(lexicalForm);
}
}
}
/**
* Converts a URI in jena node to a UriRef
* @param node
* @return UriRef
*/
public UriRef convertJenaUri2UriRef(Node node) {
if (node == null) {
throw new IllegalArgumentException("null argument not allowed");
}
return new UriRef(node.getURI());
}
/**
* Converts a jena node to a resource
* @param node
* @return BNode if it is a Blank Node, UriRef if it is a URI and Literal if it is a literal.
*/
public Resource convertJenaNode2Resource(Node node) {
if (node == null) {
throw new IllegalArgumentException("null argument not allowed");
}
if (node.isBlank()) {
return convertJenaNode2TriaBlankNode(node);
}
if (node.isURI()) {
return convertJenaUri2UriRef(node);
}
if (node.isLiteral()) {
return convertJenaLiteral2Literal(node);
}
throw new RuntimeException("cannot convert " + node + " to Resource");
}
/**
* Converts a node to a BNode if it is a Blank Node otherwise to a UriRef.
* If node is a BNode and no mapping to a Blank Node exists, then null is
* returned, otherwise the existing mapping.
*
* @param node
* @return BNode if it is a Blank Node otherwise a UriRef
*/
public NonLiteral convertNonLiteral(Node node) {
if (node == null) {
throw new IllegalArgumentException("null argument not allowed");
}
if (node.isBlank()) {
return convertJenaNode2TriaBlankNode(node);
}
if (node.isURI()) {
return convertJenaUri2UriRef(node);
}
throw new RuntimeException("cannot convert " + node + " to NonLiteral");
}
public Triple convertTriple(com.hp.hpl.jena.graph.Triple triple) {
NonLiteral subject = convertNonLiteral(triple.getSubject());
UriRef predicate = convertJenaUri2UriRef(triple.getPredicate());
Resource object = convertJenaNode2Resource(triple.getObject());
if (subject == null || object == null) {
return null;
}
return new TripleImpl(subject, predicate, object);
}
}