Java Dataset.begin方法代碼示例

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
/**
 * Import the data into the data set. When a new data set is imported the old data is deleted. 
 * @param dataset
 * @param file
 */
public void loadData(Dataset dataset, String file){
    log.info("Start loading") ;
    long startTime = System.nanoTime() ;
    dataset.begin(ReadWrite.WRITE) ;
    try {
        Model m = dataset.getDefaultModel() ;
        log.info("Number of triples before loading: " + m.size());
        RDFDataMgr.read(m, file) ;
        log.info("Number of triples after loading: " + m.size());
        dataset.commit() ;
    } 
    finally { 
        dataset.end() ;
    }
    long finishTime = System.nanoTime() ;
    double time = (finishTime-startTime)/1.0e6 ;
    log.info(String.format("Finish loading - %.2fms", time)) ;
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
/**
 * Load jena TDB
 */
private void TDBloading(){

	logger.info("TDB loading");

	// create model from tdb
	Dataset dataset = TDBFactory.createDataset(tdbDirectory);

	// assume we want the default model, or we could get a named model here
	dataset.begin(ReadWrite.READ);
	model = dataset.getDefaultModel();
	dataset.end() ;

	// if model is null load local dataset into jena TDB
	if(model == null)
		TDBloading(datasetFile);

}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
private static void demoOfReadTransaction(Dataset dataset) {
	dataset.begin(ReadWrite.READ);

	// Get model inside the transaction
	Model model = dataset.getDefaultModel();

	// query the inserted facts
	StringBuilder query = SPARQLUtils.getRegualrSPARQLPREFIX();
	query.append("PREFIX foaf: <http://xmlns.com/foaf/0.1/>").append(Constants.NEWLINE);
	query.append("SELECT DISTINCT ?person WHERE {?person rdf:type foaf:Person}");
	SPARQLUtils.query(model, query.toString(), "?person");

	model.close();// closing the model to flush

	dataset.end();
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
private static void demoOfWriteTransaction(Dataset dataset) {
	dataset.begin(ReadWrite.WRITE);

	Model model = dataset.getDefaultModel();

	ModelUtils.fillModel(model, FOAF_BASE_URI, FOAF_SCHEMA_FilePath);

	// insert foaf:me rdf:type foaf:Person
	Resource me = model.createResource(FOAF_BASE_URI + "me");
	Property rdfType = model.getProperty(Constants.RDF_TYPE_URL);
	Resource FOAFPersonClass = model.getResource(FOAF_BASE_URI + "Person");
	model.add(me, rdfType, FOAFPersonClass);
	// model.write(System.out);// for debug

	model.close();// closing the model to flush

	dataset.commit();

	dataset.end();
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
@Test
public void addModel() throws Exception {
  final Dataset ds = TDBFactory.createDataset();
  final DatasetPopulator dsp = new DatasetPopulator(ds);

  final Model model = ModelFactory.createDefaultModel();
  final Resource s = model.createResource();
  final Property p = model.createProperty("urn:example:prop", "foo");
  final Resource o = model.createResource();
  model.add(s, p, o);

  dsp.addModel(model);

  ds.begin(ReadWrite.READ);

  try {
    assertTrue(ds.getDefaultModel().containsAll(model));
  } finally {
    ds.end();
  }
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
@Test
public void inferMissingPropertyNames() throws Exception {
  final Dataset ds = TDBFactory.createDataset();
  final DatasetPopulator dsp = new DatasetPopulator(ds);
  dsp.addModel(loadModel("infer-property-names/data.ttl"));

  final Model x = loadModel("infer-property-names/expected.ttl");

  ds.begin(ReadWrite.READ);

  try {
    final Model m = ds.getDefaultModel();
    assertTrue(m.containsAll(x));
  } finally {
    ds.end();
  }
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
@Test
public void test_rdfcreation_fb() throws SAXException, IOException, ParserConfigurationException, Exception {

    Document dataDoc = parser.parse(RdfFactoryTest.class.getResourceAsStream(
            "/data/fb-20121231.xml"), -1);

    RdfFactory factory = new RdfFactory(new RunConfig(domain));
    factory.createRdfs(dataDoc, testTdbDir);

    Dataset dataset = TDBFactory.createDataset(testTdbDir);
    dataset.begin(ReadWrite.READ);
    Model model = dataset.getDefaultModel();
    Assert.assertFalse("No RDF was generated. TDB directory: " + testTdbDir, model.isEmpty());

    dataset.end();
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
@Test
public void test_rdfcreation_msft() throws SAXException, IOException, ParserConfigurationException, Exception {

    Document dataDoc = parser.parse(RdfFactoryTest.class.getResourceAsStream(
            "/data/msft-20130630.xml"), -1);

    RdfFactory factory = new RdfFactory(new RunConfig(domain));
    factory.createRdfs(dataDoc, testTdbDir);

    Dataset dataset = TDBFactory.createDataset(testTdbDir);
    dataset.begin(ReadWrite.READ);
    Model model = dataset.getDefaultModel();
    Assert.assertFalse("No RDF was generated. TDB directory: " + testTdbDir, model.isEmpty());

    dataset.end();
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
public boolean isCachedGraph(Dataset dataset, String graphName){
    boolean isCached = false;
    dataset.begin(ReadWrite.READ);
    try {
        Iterator<String> inames = getDataset().listNames();
        while(inames.hasNext()){
            if( graphName.equals( inames.next() )) {
                 isCached = true;  
            }
        }
    }
    finally {
        dataset.end();
    }
    return isCached;
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
private int queryData(Dataset dataset, String toponym){
    int addressCounter = 0;
    log.info("START") ;
    
    long startTime = System.nanoTime() ;
    
    String pre = StrUtils.strjoinNL( 
        "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>" ,
        "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>" ,
        "PREFIX schema: <http://schema.org/>" ,
        "PREFIX text: <http://jena.apache.org/text#>" ,
        "PREFIX ogc: <http://www.opengis.net/ont/geosparql#>") ;
    String qs = StrUtils.strjoinNL( "SELECT DISTINCT ?s ?address ?wkt " ,
                                " { ?s text:query (schema:streetAddress '" + toponym + "') ;" ,
                                "      schema:streetAddress ?address ;" ,
                                "      ogc:geometry ?geo ." ,
                                "   ?geo ogc:asWKT ?wkt ." ,
                                " }") ;
    
    dataset.begin(ReadWrite.READ) ;
    try {
        Query q = QueryFactory.create(pre + "\n" + qs) ;
        QueryExecution qexec = QueryExecutionFactory.create(q , dataset) ;
        //QueryExecUtils.executeQuery(q, qexec) ;
        ResultSet results = qexec.execSelect();            
        for( ; results.hasNext(); ){
            addressCounter++;
            QuerySolution sol = results.nextSolution();
            System.out.println( sol.get("s") );
            
        }
    } 
    finally { 
        dataset.end() ; 
    }
    long finishTime = System.nanoTime() ;
    double time = (finishTime-startTime)/1.0e6 ;
    log.info(String.format("FINISH - %.2fms", time)) ;
    return addressCounter;
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
/**
 * Create a transactional in-memory dataset and load data from a given URI.
 * <p/>
 * The dataset returned by {@link RDFDataMgr#loadDataset(String)} is not transactional.
 *
 * @param uri URI of data to load
 *
 * @return a new dataset
 */
public static Dataset loadDataset(final String uri) {
  final Dataset ds = TDBFactory.createDataset();
  ds.begin(ReadWrite.WRITE);
  try {
    RDFDataMgr.read(ds, uri);
    ds.commit();
  } finally {
    ds.end();
  }
  return ds;
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
private void copyFromTdb( Dataset dataset ) throws RepositoryException {
	ValueFactory vf = rc.getValueFactory();

	if ( dataset.supportsTransactions() ) {
		dataset.begin( ReadWrite.READ );
	}

	// Get model inside the transaction
	Model model = dataset.getDefaultModel();
	StmtIterator si = model.listStatements();

	try {
		rc.begin();
		while ( si.hasNext() ) {
			Statement stmt = si.next();
			com.hp.hpl.jena.rdf.model.Resource rsr = stmt.getSubject();
			Property pred = stmt.getPredicate();
			RDFNode val = stmt.getObject();
			Node valnode = val.asNode();
			
			Resource sub;
			try {
				sub = ( rsr.isAnon()
						? vf.createBNode( valnode.getBlankNodeLabel() )
						: vf.createURI( rsr.toString() ) );
			}
			catch ( UnsupportedOperationException uoo ) {
				log.warn( uoo, uoo );
				continue;
			}
			
			URI pred2 = vf.createURI( pred.toString() );
			Value val2;

			if ( val.isLiteral() ) {
				Literal lit = val.asLiteral();
				String dtstr = lit.getDatatypeURI();
				URI dt = ( null == dtstr ? null : vf.createURI( dtstr ) );
				String langstr = lit.getLanguage();

				if ( null == dt ) {
					if ( langstr.isEmpty() ) {
						val2 = vf.createLiteral( lit.toString() );
					}
					else {
						val2 = vf.createLiteral( lit.toString(), langstr );
					}
				}
				else {
					val2 = vf.createLiteral( lit.toString(), dt );
				}
			}
			else {
				if ( val.isAnon() ) {
					val2 = vf.createBNode( valnode.getBlankNodeLabel() );
				}
				else {
					val2 = vf.createURI( val.toString() );
				}
			}
			rc.add( sub, pred2, val2 );
		}
		rc.commit();
	}
	catch ( RepositoryException re ) {
		rc.rollback();
		throw re;
	}
	finally {
		if ( dataset.supportsTransactions() ) {
			dataset.end();
		}
	}
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
/**
 * Search for an address (a node in OSM).
 * @param graph The input graph contains a schema:streetAddress with the name of the street, the locality and the country code .
 * @return Returns the geocoordinates of the street that has been found. 
 */
private TripleCollection geocodeAddress(Dataset ds, Address address){
    TripleCollection geoCodeRdf = new SimpleMGraph();
    
    String pre = StrUtils.strjoinNL( 
        "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>" ,
        "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>" ,
        "PREFIX schema: <http://schema.org/>" ,
        "PREFIX text: <http://jena.apache.org/text#>" ,
        "PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>" ,
        "PREFIX ogc: <http://www.opengis.net/ont/geosparql#>") ;
    
    String qs = StrUtils.strjoinNL( "SELECT ?s ?street ?lat ?lon" ,
                                " { ?s text:query (schema:streetAddress '" + address.getStreetAddress() + "') ;" ,
                                "      schema:streetAddress ?street ;" ,
                                "      schema:addressLocality \"" + address.getLocality() + "\" ;" ,
                                "      schema:addressCountry \"" + address.getCountryCode() + "\" ;" ,
                                "      geo:lat ?lat ;" ,
                                "      geo:long ?lon ." ,                                                                       
                                " }") ;
    
    log.info(pre + "\n" + qs);
    
    ds.begin(ReadWrite.READ) ;
    try {
        Query q = QueryFactory.create(pre + "\n" + qs) ;
        QueryExecution qexec = QueryExecutionFactory.create(q , ds) ;
        //QueryExecUtils.executeQuery(q, qexec) ;
        ResultSet results = qexec.execSelect();   
        int numberOfAddresses = 0;
        for( ; results.hasNext(); ){
            QuerySolution sol = results.nextSolution();
            String streetUriName = sol.getResource("s").getURI();
            String streetName = sol.getLiteral("?street").getString();  
            String latitude = sol.getLiteral("?lat").getLexicalForm();
            String longitude = sol.getLiteral("?lon").getLexicalForm();
            UriRef addressRef = new UriRef(streetUriName);                
            geoCodeRdf.add(new TripleImpl(addressRef, schema_streetAddress, new PlainLiteralImpl(streetName)));
            geoCodeRdf.add(new TripleImpl(addressRef, schema_addressLocality, new PlainLiteralImpl( address.getLocality())) );
            geoCodeRdf.add(new TripleImpl(addressRef, schema_addressCountry, new PlainLiteralImpl( address.getCountryCode())) );
            geoCodeRdf.add(new TripleImpl(addressRef, geo_lat, new PlainLiteralImpl( latitude )) );
            geoCodeRdf.add(new TripleImpl(addressRef, geo_lon, new PlainLiteralImpl( longitude )) );
            numberOfAddresses++;
        }
        log.info("Number of addresses like " + address.getStreetAddress() + " found: " + numberOfAddresses);
    } 
    finally { 
        ds.end() ; 
    }
    
    return geoCodeRdf;
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
/**
 * Search for a street (way in OSM) 
 * @param graph The input graph contain a schema:streetAddress with the name of the street.
 * @return Returns the geometry of the street that has been found with the coordinates serialized as WKT. 
 */
private TripleCollection geocodeStreet(Dataset ds, Address address){
    TripleCollection geoCodeRdf = new SimpleMGraph();
    
    String pre = StrUtils.strjoinNL( 
        "PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>" ,
        "PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>" ,
        "PREFIX schema: <http://schema.org/>" ,
        "PREFIX text: <http://jena.apache.org/text#>" ,
        "PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>" ,
        "PREFIX ogc: <http://www.opengis.net/ont/geosparql#>") ;
    
    String qs = StrUtils.strjoinNL( "SELECT ?s ?street ?geometry ?wkt " ,
                                " { ?s text:query (schema:streetAddress '" + address.getStreetAddress() + "') ;" ,
                                "      schema:streetAddress ?street ;" ,
                                "      schema:addressLocality " + address.getLocality() + " ;" ,
                                "      schema:addressCountry " + address.getCountryCode() + " ;" ,
                                "      ogc:geometry ?geometry ." ,
                                "   ?geo ogc:asWKT ?wkt ." ,
                                " }") ;
    
    System.out.println(pre + "\n" + qs);
    
    ds.begin(ReadWrite.READ) ;
    try {
        Query q = QueryFactory.create(pre + "\n" + qs) ;
        QueryExecution qexec = QueryExecutionFactory.create(q , ds) ;
        //QueryExecUtils.executeQuery(q, qexec) ;
        ResultSet results = qexec.execSelect();   
        int numberOfToponyms = 0;
        for( ; results.hasNext(); ){
            QuerySolution sol = results.nextSolution();
            String streetUriName = sol.getResource("s").getURI();
            String streetName = sol.getLiteral("?street").getString();
            Resource geo = sol.getResource("?geo");
            String geoUri = geo.getURI();
            String wkt = sol.getLiteral("?wkt").getString();
            UriRef streetRef = new UriRef(streetUriName);
            UriRef geometryRef = new UriRef(geoUri);
            geoCodeRdf.add(new TripleImpl(streetRef, schema_streetAddress, new PlainLiteralImpl(streetName) ));
            geoCodeRdf.add(new TripleImpl(streetRef, schema_addressLocality, new PlainLiteralImpl( address.getLocality())) );
            geoCodeRdf.add(new TripleImpl(streetRef, schema_addressCountry, new PlainLiteralImpl( address.getCountryCode())) );
            geoCodeRdf.add(new TripleImpl(streetRef, new UriRef("http://www.opengis.net/ont/geosparql#geometry"), geometryRef));
            geoCodeRdf.add(new TripleImpl(geometryRef, new UriRef("http://www.opengis.net/ont/geosparql#asWKT"), new PlainLiteralImpl(wkt)));
            numberOfToponyms++;
        }
        log.info("Number of toponymis like " + address.getStreetAddress() + " found: " + numberOfToponyms);
    } 
    finally { 
        ds.end() ; 
    }
    
    return geoCodeRdf;
}
 

import com.hp.hpl.jena.query.Dataset; //導入方法依賴的package包/類
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_rdfread_write);

    TextView textView = (TextView) findViewById(R.id.rdfTextView);
    textView.setMovementMethod(new ScrollingMovementMethod());

    // create tdb dataset
    File directory = new File(getFilesDir(), "tdb_dataset");
    directory.delete();
    directory.mkdir();
    Dataset dataset = TDBFactory.createDataset(directory.getAbsolutePath()) ;
    dataset.begin(ReadWrite.WRITE);
    Model model = dataset.getDefaultModel();

    // read a turtle file from assets and write them into a tdb backed model
    try {
        InputStream skos_ttl = getAssets().open("skos.ttl");
        RDFDataMgr.read(model, skos_ttl, Lang.TURTLE);
        skos_ttl.close();
        InputStream geosparql_rdf_xml = getAssets().open("geosparql_vocab_all.rdf");
        RDFDataMgr.read(model, geosparql_rdf_xml, Lang.RDFXML);
        geosparql_rdf_xml.close();
    } catch (IOException e) {
        Log.e(TAG, e.toString());
        e.printStackTrace();
    }

    // add some example data
    String personURI    = "http://somewhere/JohnSmith";
    String fullName     = "John Smith";
    Resource johnSmith = model.createResource(personURI);
    johnSmith.addProperty(VCARD.FN, fullName);

    dataset.commit();
    dataset.end();

    // read from tdb and print triples
    dataset.begin(ReadWrite.READ);
    Query query = QueryFactory.create("SELECT * WHERE { ?s ?p ?o } LIMIT 2");
    QueryExecution qexec = QueryExecutionFactory.create(query, model);
    ResultSet results = qexec.execSelect();
    String resultString = ResultSetFormatter.asText(results);
    Log.d(TAG, resultString);

    StringWriter dump = new StringWriter();
    RDFDataMgr.write(dump, dataset, RDFFormat.JSONLD_PRETTY);

    dataset.end();
    dataset.close();

    textView.setText(dump.toString());

}