/**
* Copyright (c) 2013, Institute of Information Systems (Sven Groppe and contributors of LUPOSDATE), University of Luebeck
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this list of conditions and the following
* disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* - Neither the name of the University of Luebeck nor the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package lupos.event.producer.rsssemantics;
import lupos.datastructures.bindings.Bindings;
import lupos.datastructures.bindings.BindingsMap;
import lupos.datastructures.items.literal.LiteralFactory;
import lupos.datastructures.items.literal.URILiteral;
import lupos.datastructures.queryresult.QueryResult;
import lupos.engine.evaluators.MemoryIndexQueryEvaluator;
import java.util.LinkedList;
import lupos.sparql1_1.operatorgraph.ServiceApproaches;
/**
* Establishes a connection to the database and sends queries.
*/
public class QueryDB {
static {
/**
* Define Literal type
*/
LiteralFactory.setType(LiteralFactory.MapType.HASHMAP);
Bindings.instanceClass = BindingsMap.class;
/**
* Initialize JoinApproach
*/
ServiceApproaches.Semijoin_Approach.setup();
}
private String query;
public QueryDB(String query) {
this.query = query;
}
public QueryResult query() {
try {
MemoryIndexQueryEvaluator evaluator = new MemoryIndexQueryEvaluator();
evaluator.prepareInputData(new LinkedList<URILiteral>(),
new LinkedList<URILiteral>());
/**
* Query database
*/
QueryResult qr = evaluator.getResult(this.query);
return qr;
} catch (Exception e) {
System.out
.println("Connection to database could not be established.");
e.printStackTrace();
return null;
}
}
}