`/*
* (c) Copyright 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
* All rights reserved.
* [See end of file]
*/
package arq.examples;
// The ARQ application API.
import com.hp.hpl.jena.sparql.util.IndentedWriter;
import com.hp.hpl.jena.query.*;
import com.hp.hpl.jena.rdf.model.*;
import com.hp.hpl.jena.vocabulary.DC;
/** Example 1 : Execute a simple SELECT query on a model
* to find the DC titles contained in a model.
*
* @author Andy Seaborne
*/
public class Ex1
{
static public final String NL = System.getProperty("line.separator") ;
public static void main(String[] args)
{
// Create the data.
// This wil be the background (unnamed) graph in the dataset.
Model model = createModel() ;
// First part or the query string
String prolog = "PREFIX dc: <"+DC.getURI()+">" ;
// Query string.
String queryString = prolog + NL +
"SELECT ?title WHERE {?x dc:title ?title}" ;
Query query = QueryFactory.create(queryString) ;
// Print with line numbers
query.serialize(new IndentedWriter(System.out,true)) ;
System.out.println() ;
// Create a single execution of this query, apply to a model
// which is wrapped up as a Dataset
QueryExecution qexec = QueryExecutionFactory.create(query, model) ;
// Or QueryExecutionFactory.create(queryString, model) ;
System.out.println("Titles: ") ;
try {
// Assumption: it's a SELECT query.
ResultSet rs = qexec.execSelect() ;
// The order of results is undefined.
for ( ; rs.hasNext() ; )
{
QuerySolution rb = rs.nextSolution() ;
// Get title - variable names do not include the '?' (or '$')
RDFNode x = rb.get("title") ;
// Check the type of the result value
if ( x.isLiteral() )
{
Literal titleStr = (Literal)x ;
System.out.println(" "+titleStr) ;
}
else
System.out.println("Strange - not a literal: "+x) ;
}
}
finally
{
// QueryExecution objects should be closed to free any system resources
qexec.close() ;
}
}
public static Model createModel()
{
Model m = ModelFactory.createDefaultModel() ;
Resource r1 = m.createResource("http://example.org/book#1") ;
Resource r2 = m.createResource("http://example.org/book#2") ;
r1.addProperty(DC.title, "SPARQL - the book")
.addProperty(DC.description, "A book about SPARQL") ;
r2.addProperty(DC.title, "Advanced techniques for SPARQL") ;
return m ;
}
}
/*
* (c) Copyright 2005, 2006, 2007, 2008 Hewlett-Packard Development Company, LP
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/`