Examples with Dataset org.apache.jena.query.Dataset used on opensource projects

Example 71 with Dataset

use of org.apache.jena.query.Dataset in project jena by apache.

the class ExTDB4 method main.

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);
    QueryExecution qexec = QueryExecutionFactory.create(query, dataset);
    ResultSet results = qexec.execSelect();
    ResultSetFormatter.out(results);
    qexec.close();
    dataset.close();
}

Example 72 with Dataset

use of org.apache.jena.query.Dataset in project jena by apache.

the class ExTDB_Txn1 method main.

public static void main(String... argv) {
    String directory = "MyDatabases/DB1";
    Dataset dataset = TDBFactory.createDataset(directory);
    // Start READ transaction. 
    //   No updates or changes to the dataset are possible while this
    //   dataset is used for a read transaction.
    //   An application can have other Datasets, in the same JVM, 
    //   tied to the same TDB database performing read or write
    //   transactions concurrently.
    dataset.begin(ReadWrite.READ);
    try {
        // Do some queries
        String sparqlQueryString1 = "SELECT (count(*) AS ?count) { ?s ?p ?o }";
        execQuery(sparqlQueryString1, dataset);
        String sparqlQueryString2 = "SELECT * { ?s ?p ?o }";
        execQuery(sparqlQueryString2, dataset);
    // Can also call dataset.abort() or dataset.commit() here 
    } finally {
        // Notify the end of the READ transaction.
        // Any use of dataset.abort() or dataset.commit() or dataset.end()
        // .end() can be called multiple times for the same .begin(READ)
        dataset.end();
    }
}

Example 73 with Dataset

use of org.apache.jena.query.Dataset in project jena by apache.

the class TDBBackup method backup.

public static void backup(Location location, OutputStream backupfile) {
    Dataset ds = TDBFactory.createDataset(location);
    StoreConnection sConn = StoreConnection.make(location);
    DatasetGraphTxn dsg = sConn.begin(ReadWrite.READ, "backup");
    RDFDataMgr.write(backupfile, dsg, Lang.NQUADS);
    dsg.end();
}

Example 74 with Dataset

use of org.apache.jena.query.Dataset in project jena by apache.

the class SpatialSearchUtil method joinDataset.

private static Dataset joinDataset(Dataset baseDataset, File indexDir) throws IOException {
    EntityDefinition entDef = new EntityDefinition("uri", "geo");
    // Lucene, index in File system.
    Directory dir = FSDirectory.open(indexDir.toPath());
    // Join together into a dataset
    Dataset ds = SpatialDatasetFactory.createLucene(baseDataset, dir, entDef);
    return ds;
}

Example 75 with Dataset

use of org.apache.jena.query.Dataset in project jena by apache.

the class TestTransactionTDB method transaction_50.

@Test
public void transaction_50() {
    // This assumes you have two datasets on the same location.
    // That's not necessarily true for uncached memory datasets, 
    // where you get two separate datasets so changes to one are
    // not seen by the other at all.
    Dataset ds1 = create();
    Dataset ds2 = create();
    ds1.begin(WRITE);
    ds1.getDefaultModel().getGraph().add(triple1);
    ds2.begin(READ);
    assertTrue(ds2.getDefaultModel().isEmpty());
    ds2.commit();
    ds1.commit();
    ds2.begin(READ);
    // See ds1 updates
    Graph g = ds2.getDefaultModel().getGraph();
    DatasetGraph dsg = ds2.asDatasetGraph();
    g = dsg.getDefaultGraph();
    boolean b0 = g.isEmpty();
    boolean b1 = ds2.getDefaultModel().isEmpty();
    assertFalse(ds2.getDefaultModel().isEmpty());
    assertEquals(1, ds2.getDefaultModel().size());
    ds2.commit();
}