/*
* 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.sparql;
import java.security.AccessController;
import java.security.PrivilegedAction;
import org.apache.clerezza.rdf.core.TripleCollection;
import org.apache.clerezza.rdf.core.access.TcManager;
import org.apache.clerezza.rdf.core.sparql.QueryEngine;
import org.apache.clerezza.rdf.core.sparql.query.AskQuery;
import org.apache.clerezza.rdf.core.sparql.query.ConstructQuery;
import org.apache.clerezza.rdf.core.sparql.query.DescribeQuery;
import org.apache.clerezza.rdf.core.sparql.query.Query;
import org.apache.clerezza.rdf.jena.storage.JenaGraphAdaptor;
import com.hp.hpl.jena.query.Dataset;
import com.hp.hpl.jena.query.QueryExecException;
import com.hp.hpl.jena.query.QueryExecution;
import com.hp.hpl.jena.query.QueryExecutionFactory;
import com.hp.hpl.jena.query.QueryFactory;
/**
*
* @scr.component
* @scr.service interface="org.apache.clerezza.rdf.core.sparql.QueryEngine"
*
* @author rbn
*/
public class JenaSparqlEngine implements QueryEngine {
// ------------------------------------------------------------------------
// Implementing QueryEngine
// ------------------------------------------------------------------------
@Override
public Object execute(TcManager tcManager, TripleCollection defaultGraph,
final Query query) {
final Dataset dataset = new TcDataset(tcManager, defaultGraph);
// Missing permission (java.lang.RuntimePermission getClassLoader)
// when calling QueryFactory.create causes ExceptionInInitializerError
// to be thrown.
// QueryExecutionFactory.create requires
// (java.io.FilePermission [etc/]location-mapping.* read)
// Thus, they are placed within doPrivileged
QueryExecution qexec = AccessController
.doPrivileged(new PrivilegedAction<QueryExecution>() {
@Override
public QueryExecution run() {
com.hp.hpl.jena.query.Query jenaQuery = QueryFactory
.create(query.toString());
return QueryExecutionFactory.create(jenaQuery, dataset);
}
});
try {
if (query instanceof AskQuery) {
return Boolean.valueOf(qexec.execAsk());
} else if (query instanceof DescribeQuery) {
return new JenaGraphAdaptor(qexec.execDescribe().getGraph())
.getGraph();
} else if (query instanceof ConstructQuery) {
return new JenaGraphAdaptor(qexec.execConstruct().getGraph())
.getGraph();
} else {
return new ResultSetWrapper(qexec.execSelect());
}
} finally {
qexec.close();
}
}
@Override
public Object execute(TcManager tcManager, TripleCollection defaultGraph,
final String query) {
final Dataset dataset = new TcDataset(tcManager, defaultGraph);
// Missing permission (java.lang.RuntimePermission getClassLoader)
// when calling QueryFactory.create causes ExceptionInInitializerError
// to be thrown.
// QueryExecutionFactory.create requires
// (java.io.FilePermission [etc/]location-mapping.* read)
// Thus, they are placed within doPrivileged
QueryExecution qexec = AccessController
.doPrivileged(new PrivilegedAction<QueryExecution>() {
@Override
public QueryExecution run() {
com.hp.hpl.jena.query.Query jenaQuery = QueryFactory
.create(query);
return QueryExecutionFactory.create(jenaQuery, dataset);
}
});
try {
try {
return new ResultSetWrapper(qexec.execSelect());
} catch (QueryExecException e) {
try {
return Boolean.valueOf(qexec.execAsk());
} catch (QueryExecException e2) {
try {
return new JenaGraphAdaptor(qexec.execDescribe()
.getGraph()).getGraph();
} catch (QueryExecException e3) {
return new JenaGraphAdaptor(qexec.execConstruct()
.getGraph()).getGraph();
}
}
}
} finally {
qexec.close();
}
}
}