/**
* Copyright 2012-2013 the Semargl contributors. See AUTHORS for more details.
*
* Licensed 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.semarglproject.jena.core.sink;
import com.hp.hpl.jena.datatypes.BaseDatatype;
import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.rdf.model.Model;
import org.semarglproject.sink.TripleSink;
import org.semarglproject.vocab.RDF;
import java.util.HashMap;
import java.util.Map;
/**
* Base class to provide custom implementations of TripleSinks for Jena
*/
public abstract class AbstractJenaSink implements TripleSink {
/**
* Used as a key with {@link #setProperty(String, Object)} method.
* Allows to specify Jena's model to sink triples to.
* Subclass of {@link Model} must be passed as a value.
*/
public static final String OUTPUT_MODEL_PROPERTY = "http://semarglproject.org/jena/properties/output-model";
protected Model model;
private final Map<String, Node> bnodeMap;
protected AbstractJenaSink(Model model) {
this.model = model;
bnodeMap = new HashMap<String, Node>();
}
private Node getBNode(String bnode) {
if (!bnodeMap.containsKey(bnode)) {
bnodeMap.put(bnode, Node.createAnon());
}
return bnodeMap.get(bnode);
}
private Node convertNonLiteral(String arg) {
if (arg.startsWith(RDF.BNODE_PREFIX)) {
return getBNode(arg);
}
return Node.createURI(arg);
}
@Override
public final void addNonLiteral(String subj, String pred, String obj) {
addTriple(convertNonLiteral(subj), Node.createURI(pred), convertNonLiteral(obj));
}
@Override
public final void addPlainLiteral(String subj, String pred, String content, String lang) {
if (lang == null) {
addTriple(convertNonLiteral(subj), Node.createURI(pred), Node.createLiteral(content));
} else {
addTriple(convertNonLiteral(subj), Node.createURI(pred),
Node.createLiteral(content, lang, false));
}
}
@Override
public final void addTypedLiteral(String subj, String pred, String content, String type) {
Node literal = Node.createLiteral(content, "", new BaseDatatype(type));
addTriple(convertNonLiteral(subj), Node.createURI(pred), literal);
}
@Override
public boolean setProperty(String key, Object value) {
if (OUTPUT_MODEL_PROPERTY.equals(key) && value instanceof Model) {
model = (Model) value;
return true;
}
return false;
}
/**
* Callback method for handling Jena triples.
* @param subj triple's subject
* @param pred triple's predicate
* @param obj triple's object
*/
protected abstract void addTriple(Node subj, Node pred, Node obj);
}