| /* |
| * 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 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.QuerySolution; |
| import org.apache.jena.query.ResultSet; |
| 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. |
| * See also ExTDB_Txn1 for use with transactions. |
| */ |
| |
| public class ExTDB5 { |
| 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(); |
| for ( ; results.hasNext() ; ) { |
| QuerySolution soln = results.nextSolution(); |
| int count = soln.getLiteral("count").getInt(); |
| System.out.println("count = " + count); |
| } |
| } |
| } |
| } |