jena-tdb/src-examples/tdb/examples/ExTDB4.java

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 * distributed with this work for additional information
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 * 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
 *
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 */

package tdb.examples;

import org.apache.jena.query.Dataset ;
import org.apache.jena.query.Query ;
import org.apache.jena.query.QueryExecution ;
import org.apache.jena.query.QueryExecutionFactory ;
import org.apache.jena.query.QueryFactory ;
import org.apache.jena.query.ResultSet ;
import org.apache.jena.query.ResultSetFormatter ;
import org.apache.jena.tdb.TDBFactory ;

/** Example of creating a TDB-backed model.
 *  The preferred way is to create a dataset then get the mode required from the dataset.
 *  The dataset can be used for SPARQL query and update
 *  but the Model (or Graph) can also be used.
 *  
 *  All the Jena APIs work on the model.
 *   
 *  Calling TDBFactory is the only place TDB-specific code is needed.
 */

public class ExTDB4
{
    public static void main(String... argv)
    {
        // Direct way: Make a TDB-back Jena model in the named directory.
        String directory = "MyDatabases/DB1" ;
        Dataset dataset = TDBFactory.createDataset(directory) ;
        
        // Potentially expensive query.
        String sparqlQueryString = "SELECT (count(*) AS ?count) { ?s ?p ?o }" ;
        // See http://incubator.apache.org/jena/documentation/query/app_api.html
        
        Query query = QueryFactory.create(sparqlQueryString) ;
        try ( QueryExecution qexec = QueryExecutionFactory.create(query, dataset) ) {
            ResultSet results = qexec.execSelect() ;
            ResultSetFormatter.out(results) ;
        }
    }
}