Java Code Examples for com.hp.hpl.jena.query.QueryExecution#close()

/**
 * Executes a given SELECT query against a given dataset.
 * 
 * @param data the mistery guest containing test data (query and dataset)
 * @throws Exception never, otherwise the test fails.
 */
protected void selectTest(final MisteryGuest data) throws Exception {
	load(data);
	
	try {
		assertTrue(
				Arrays.toString(data.datasets) + ", " + data.query,
				ResultSetCompare.isomorphic(
						SOLRDF_CLIENT.select(queryString(data.query)),
						(inMemoryExecution = QueryExecutionFactory.create(
								QueryFactory.create(queryString(data.query)), 
								memoryDataset)).execSelect()));
	} catch (final Throwable error) {
		log.debug("JNS\n" + ResultSetFormatter.asText(SOLRDF_CLIENT.select(queryString(data.query))));
		
		QueryExecution debugExecution = null;
		log.debug("MEM\n" + ResultSetFormatter.asText(
				(debugExecution = (QueryExecutionFactory.create(
						QueryFactory.create(queryString(data.query)), 
						memoryDataset))).execSelect()));
		
		debugExecution.close();
		throw error;
	} 
}
 

/**
 * It executes a SELECT SPARQL query on the SPARQL endpoint.
 *
 * @param sparqlEndpointURI		the SPARQL endpoint URI.  
 * @param user					the user name for the SPARQl endpoint.
 * @param password				the password for the SPARQl endpoint.
 * @param query					the query to use to look for the resources.
 * @return the {@link com.hp.hpl.jena.query.ResultSet} of the SELECT SPARQL query.
 * @since 2.0
 */
public ResultSet executeSelect(final String sparqlEndpointURI, final String user, final String password, final String query) {
	ResultSet results = null;
 	try {
        // Execute the query and obtain results
        final QueryExecution qexec = QueryExecutionFactory.sparqlService(
        		sparqlEndpointURI, 
        		QueryFactory.create(query), 
				auth(sparqlEndpointURI, user, password));
        qexec.setTimeout(2000, 5000);
           results = qexec.execSelect() ;
        qexec.close() ;
      } catch (Exception exception) {
		LOGGER.error(MessageCatalog._00035_SPARQL_FAILED, exception, query);
	}
 	return results;
}
 

public List<? super PropertyResource> getPropertiesOfContext(
		String contextURI) {
	List<PropertyResource> propertyList = new ArrayList<PropertyResource>();
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_RDFS).append("SELECT ?property FROM <")
			.append(MDRDatabase.BASE_URI).append("> WHERE {")
			.append("?property rdfs:subClassOf mdr:Property .")
			.append("?property mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextContext <")
			.append(contextURI).append("> .").append("}");
	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			PropertyResource prop = new PropertyImpl(
					qs.getResource("property"), mdrDatabase);
			propertyList.add(prop);
		}
	} finally {
		qexec.close();
	}
	return propertyList;
}
 

/**
 * @param uri
 *            URI of the Context
 * @return total number of Data Element's on specified Context
 */
public int getNumberOfDataElementsOfContext(String uri) {
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_RDFS)
			.append("SELECT (COUNT(DISTINCT ?de) as ?count) FROM <")
			.append(MDRDatabase.BASE_URI).append("> WHERE {")
			.append("?de rdfs:subClassOf mdr:DataElement .")
			.append("?de mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextContext <")
			.append(uri).append("> .").append("}");
	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	int size = 0;
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			size = qs.getLiteral("count").getInt();
		}
	} finally {
		qexec.close();
	}
	return size;
}
 

public int getNumberOfDEC(String objectClassURI) {
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_RDFS)
			.append("SELECT (COUNT (DISTINCT ?dec) as ?count) FROM <")
			.append(MDRDatabase.BASE_URI).append("> WHERE {")
			.append("?dec rdfs:subClassOf mdr:DataElementConcept .")
			.append("?dec mdr:dataElementConceptObjectClass <")
			.append(objectClassURI).append("> .").append("}");
	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	int size = 0;
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			size = qs.getLiteral("count").getInt();
		}
	} finally {
		qexec.close();
	}

	return size;
}
 

@Override
public void write(
		final Writer writer, 
		final SolrQueryRequest request, 
		final SolrQueryResponse response) throws IOException {		
	final NamedList<?> values = response.getValues();
	final Query query = (Query)request.getContext().get(Names.QUERY);
	final QueryExecution execution = (QueryExecution)response.getValues().get(Names.QUERY_EXECUTION);
	try {
		final boolean isHybridMode = Boolean.TRUE.equals(request.getContext().get(Names.HYBRID_MODE));
		if (isHybridMode) {
			response.add(Names.SOLR_REQUEST, request);
			response.add(Names.SOLR_RESPONSE, response);
			
			final String contentType = contentTypeRewrites.get(getContentType(request, false));
			WriterStrategy strategy = compositeWriters.get(contentType);
			strategy = strategy != null ? strategy : compositeWriters.get("text/xml");
			strategy.doWrite(values, writer, contentType);
		} else {
			if (query == null || execution == null) {
				LOGGER.error(MessageCatalog._00091_NULL_QUERY_OR_EXECUTION);
				return;
			}
			writers.get(query.getQueryType()).doWrite(values, writer, getContentType(request, false));
		}
	} finally {
		if (execution != null) {
			// CHECKSTYLE:OFF
			try { execution.close();} catch (final Exception ignore) {}
			// CHECKSTYLE:ON
		}			
	}			
}
 

/**
 * Executes a given CONSTRUCT query against a given dataset.
 * 
 * @param data the mistery guest containing test data (query and dataset)
 * @throws Exception never, otherwise the test fails.
 */
protected void constructTest(final MisteryGuest data) throws Exception {
	load(data);
	
	try {
		inMemoryExecution = QueryExecutionFactory.create(
				QueryFactory.create(queryString(data.query)), memoryDataset);
		
		assertTrue(
				Arrays.toString(data.datasets) + ", " + data.query,
				inMemoryExecution.execConstruct().isIsomorphicWith(
						SOLRDF_CLIENT.construct(queryString(data.query))));
	} catch (final Throwable error) {
		StringWriter writer = new StringWriter();
		RDFDataMgr.write(writer, SOLRDF_CLIENT.construct(queryString(data.query)), RDFFormat.NTRIPLES);
		log.debug("JNS\n" + writer);
		
		QueryExecution debugExecution = QueryExecutionFactory.create(
				QueryFactory.create(queryString(data.query)), memoryDataset);
		
		writer = new StringWriter();
		RDFDataMgr.write(writer, debugExecution.execConstruct(), RDFFormat.NTRIPLES);
		
		log.debug("MEM\n" + writer);
		
		debugExecution.close();
		throw error;
	} 
}
 

/**
 * Executes a SPARQL CONSTRUCT.
 * 
 * @param query the SPARQL CONSTRUCT Query.
 * @return the {@link Model} that includes the CONSTRUCT result.
 * @throws UnableToExecuteQueryException in case of failure before, during or after the query execution.
 */
public Model construct(final String constructQuery) throws UnableToExecuteQueryException {
	QueryExecution execution = null;
	try {
		return (execution = execution(constructQuery)).execConstruct();
	} catch (final Exception exception) {
		throw new UnableToExecuteQueryException(exception);
	} finally {
		execution.close();
	}
}
 

/**
 * With given objectClassURI, tihs method returns a list of all
 * {@link DataElementConcept}s whose {@link ObjectClass} is given
 * 
 * @param objectClassURI
 *            Unique URI of the ObjectClass
 * @return {@link DataElementConcept}s created with given ObjectClass
 */
public List<? super DataElementConceptResource> getDECSofOC(
		String objectClassURI, Integer limit, Integer offset) {
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_RDFS).append("SELECT ?dec FROM <")
			.append(MDRDatabase.BASE_URI).append("> WHERE {")
			.append("?dec rdfs:subClassOf mdr:DataElementConcept .")
			.append("?dec mdr:dataElementConceptObjectClass <")
			.append(objectClassURI).append("> .").append("}");
	if (limit != null && offset != null) {
		queryString.append(" LIMIT ").append(limit).append(" OFFSET ")
				.append(offset);
	}
	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	List<DataElementConceptResource> decResourceList = new ArrayList<DataElementConceptResource>();
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			DataElementConceptResource ctx = new DataElementConceptImpl(
					qs.getResource("dec"), this.mdrDatabase);
			decResourceList.add(ctx);
		}
	} finally {
		qexec.close();
	}
	return decResourceList;
}
 

public List<? super DataElementResource> getDataElementsOfContext(
		String contextURI, Integer limit, Integer offset) {
	List<DataElementResource> dataElementResourceList = new ArrayList<DataElementResource>();

	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_RDFS).append("SELECT ?de FROM <")
			.append(MDRDatabase.BASE_URI).append("> WHERE {")
			.append("?de rdfs:subClassOf mdr:DataElement .")
			.append("?de mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextContext <")
			.append(contextURI).append("> .").append("}");
	if (limit != null && offset != null) {
		queryString.append(" ORDER BY ?de ").append(" LIMIT ")
				.append(limit).append(" OFFSET ").append(offset);
	}
	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());

	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			DataElementResource ctx = new DataElementImpl(
					qs.getResource("de"), this.mdrDatabase);
			dataElementResourceList.add(ctx);
		}
	} finally {
		qexec.close();
	}
	return dataElementResourceList;

}
 

/**
 * It executes a SELECT SPARQL query on the SPARQL endpoint, 
 * to get the discovered links.
 *
 * @param sparqlEndpointURI		the SPARQL endpoint URI.  
 * @param graphName 			the graphName, null in case of default graph.
 * @param user					the user name for the SPARQl endpoint.
 * @param password				the password for the SPARQl endpoint.
 * @param offset				causes the solutions generated to start after 
 *                              the specified number of solutions.
 * @param limit					upper bound on the number of solutions returned.
 * @return a list of triples with the discovered links.
 * @since 2.0
 */
public Triple[] getDiscoveredLinks(final String sparqlEndpointURI, final String graphName, final String user, final String password, final int offset, final int limit) {
	final String query = "select * FROM <" + graphName + "> " + 
					"where {?source ?rel ?target }" +
					" ORDER BY ?source ?target" +
					" OFFSET " + offset + " LIMIT " + limit;
  	ArrayList<Triple> linksList = new ArrayList<Triple>();
 	try {
        // Execute the query and obtain results
        final QueryExecution qexec = QueryExecutionFactory.sparqlService(
        		sparqlEndpointURI, 
        		QueryFactory.create(query), 
				auth(sparqlEndpointURI, user, password));
        qexec.setTimeout(2000, 5000);
           final ResultSet results = qexec.execSelect() ;
           while (results.hasNext())
           {
           	final QuerySolution soln = results.nextSolution() ;
           	final Resource sourceResType = soln.getResource("source");
           	final Resource targetResType = soln.getResource("target");
           	final Resource relResType = soln.getResource("rel");
       		final Triple triple = new Triple(sourceResType.asNode(), relResType.asNode(), targetResType.asNode());
       		linksList.add(triple);
           }
        qexec.close() ;
      } catch (Exception exception) {
		LOGGER.error(MessageCatalog._00035_SPARQL_FAILED, exception, query);
	}
	if (linksList.isEmpty()) {
		return new Triple[0];
	}
	return (Triple[]) linksList.toArray(new Triple[linksList.size()]);
}
 

@Override
public List<? super PropertyResource> searchProperty(String keyword,
		String contextURI, TextSearchType searchType) {
	List<PropertyResource> propertyList = new ArrayList<PropertyResource>();
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_RDFS)
			.append("SELECT ?property FROM <")
			.append(MDRDatabase.BASE_URI)
			.append("> WHERE {")
			.append("?property rdfs:subClassOf mdr:Property .")
			.append("?property mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextTerminologicalEntry ?te .")
			.append("?te mdr:containingTerminologicalEntryLanguage ?ls .")
			.append("?ls mdr:containingNameEntry ?designation .")
			.append("?designation mdr:name ?name .");
	if (!Util.isNull(contextURI)) {
		queryString.append("?aic mdr:administeredItemContextContext <")
				.append(contextURI).append("> .");
	}
	if (keyword.matches("\\s*")) {
		return propertyList;
	}
	if (searchType == null || searchType.equals(TextSearchType.Exact)) {
		queryString.append(exactMatchKeyword(keyword));
	}

	else if (searchType.equals(TextSearchType.WildCard)) {
		queryString.append(atLeastOneKeyword(keyword));
	}

	else {
		queryString.append(allWordsKeyword(keyword));
	}
	queryString.append(" .}");

	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			PropertyResource prop = new PropertyImpl(
					qs.getResource("property"), mdrDatabase);
			propertyList.add(prop);
		}
	} finally {
		qexec.close();
	}
	return propertyList;
}
 

@Override
public List<? super PropertyResource> searchProperty(String keyword,
		String contextURI, TextSearchType searchType) {
	List<PropertyResource> propertyList = new ArrayList<PropertyResource>();
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_PF)
			.append(PREFIX_RDFS)
			.append("SELECT ?property FROM <")
			.append(MDRDatabase.BASE_URI)
			.append("> WHERE {")
			.append("?property rdfs:subClassOf mdr:Property .")
			.append("?property mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextTerminologicalEntry ?te .")
			.append("?te mdr:containingTerminologicalEntryLanguage ?ls .")
			.append("?ls mdr:containingNameEntry ?designation .")
			.append("?designation mdr:name ?name .");
	if (!Util.isNull(contextURI)) {
		queryString.append("?aic mdr:administeredItemContextContext <")
				.append(contextURI).append("> . ");
	}
	if (keyword.matches("\\s*")) {
		return propertyList;
	}
	if (searchType == null || searchType.equals(TextSearchType.Exact)) {
		queryString.append(exactMatchKeyword(keyword));
	}

	else if (searchType.equals(TextSearchType.WildCard)) {
		queryString.append(atLeastOneKeyword(keyword));
	}

	else {
		queryString.append(allWordsKeyword(keyword));
	}
	queryString.append(" .}");
	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			PropertyResource prop = new PropertyImpl(
					qs.getResource("property"), mdrDatabase);
			propertyList.add(prop);
		}
	} finally {
		qexec.close();
	}
	return propertyList;
}
 

@Override
public int getNumberOfDataElementSearch(String keyword, String contextURI,
		TextSearchType searchType) {
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_RDFS)
			.append("SELECT (COUNT (DISTINCT ?de) as ?count) FROM <")
			.append(MDRDatabase.BASE_URI)
			.append("> WHERE {")
			.append("?de rdfs:subClassOf mdr:DataElement .")
			.append("?de mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextTerminologicalEntry ?te .")
			.append("?te mdr:containingTerminologicalEntryLanguage ?ls .")
			.append("?ls mdr:containingNameEntry ?designation .")
			.append("?designation mdr:name ?name .");
	if (!Util.isNull(contextURI)) {
		queryString.append("?aic mdr:administeredItemContextContext <")
				.append(contextURI).append("> .");
	}
	// checks if keyword is empty
	if (keyword.matches("\\s*")) {
		return 0;
	}
	if (searchType == null || searchType.equals(TextSearchType.Exact)) {
		queryString.append(exactMatchKeyword(keyword));
	}

	else if (searchType.equals(TextSearchType.WildCard)) {
		queryString.append(atLeastOneKeyword(keyword));
	}

	else {
		queryString.append(allWordsKeyword(keyword));
	}
	queryString.append(" .}");

	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	int size = 0;
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			size = qs.getLiteral("count").getInt();
		}
	} finally {
		qexec.close();
	}
	return size;
}
 

/**
 * It executes a SELECT SPARQL query on the SPARQL endpoint, to get the 
 * URIs of a type from ALIADA ontology.
 *
 * @param sparqlEndpointURI		the SPARQL endpoint URI.  
 * @param user					the user name for the SPARQl endpoint.
 * @param password				the password for the SPARQl endpoint.
 * @param typeLabel				the label value of the type to search for.
 * @return a list of URIs with the matched types.
 * @since 1.0
 */
public String[] getOntologyTypeURI(final String sparqlEndpointURI, final String user, final String password, final String typeLabel) {
	final String query = "select distinct ?type FROM <http://aliada-project.eu/2014/aliada-ontology#> " + 
					"where {?type a <http://www.w3.org/2004/02/skos/core#Concept> . " +
					"?type <http://www.w3.org/2004/02/skos/core#prefLabel> ?label . " +
					"FILTER regex(str(?label), \"^" + typeLabel + "$\")}";
	final ArrayList<String> typesList = new ArrayList<String>();
	QueryExecution qexec = null;
	try {
        // Execute the query and obtain results
  		qexec = QueryExecutionFactory.sparqlService(
  				sparqlEndpointURI, 
        		QueryFactory.create(query), 
				auth(sparqlEndpointURI, user, password));
           
        if (qexec instanceof QueryEngineHTTP) {
        	((QueryEngineHTTP)qexec).setTimeout(2000L, 5000L);
        }
        
        final ResultSet results = qexec.execSelect() ;
           while (results.hasNext()) {
           	final QuerySolution soln = results.nextSolution() ;
           	final Resource resType = soln.getResource("type");
       		final String type = resType.getURI();
       		typesList.add(type);
           }
  	} catch (Exception exception) {
  		LOGGER.error(MessageCatalog._00035_SPARQL_FAILED, exception, query);
  	} finally {
  		try {
			qexec.close();
		} catch (Exception e) {
			// Ignore
		}
  	}
 	
	if (typesList.isEmpty()) {
		return new String[0];
	}
	return (String[]) typesList.toArray(new String[typesList.size()]);
}
 

@Override
public List<? super ConceptualDomainResource> searchConceptualDomain(
		String keyword, String contextURI, TextSearchType searchType) {
	List<ConceptualDomainResource> cdList = new ArrayList<ConceptualDomainResource>();
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_PF)
			.append(PREFIX_RDFS)
			.append("SELECT ?cd FROM <")
			.append(MDRDatabase.BASE_URI)
			.append("> WHERE {")
			.append("?cdClass rdfs:subClassOf mdr:ConceptualDomain .")
			.append("?cd rdfs:subClassOf ?cdClass .")
			.append("?cd mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextTerminologicalEntry ?te .")
			.append("?te mdr:containingTerminologicalEntryLanguage ?ls .")
			.append("?ls mdr:containingNameEntry ?designation .")
			.append("?designation mdr:name ?name .");
	if (!Util.isNull(contextURI)) {
		queryString.append("?aic mdr:administeredItemContextContext <")
				.append(contextURI).append("> .");
	}
	if (keyword.matches("\\s*")) {
		return cdList;
	}
	if (searchType == null || searchType.equals(TextSearchType.Exact)) {
		queryString.append(exactMatchKeyword(keyword));
	}

	else if (searchType.equals(TextSearchType.WildCard)) {
		queryString.append(atLeastOneKeyword(keyword));
	}

	else {
		queryString.append(allWordsKeyword(keyword));
	}
	queryString.append(" .}");

	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			// here conceptualDomain is checked whether its enumerated or
			// not, proper instantiation is done
			OntClass res = qs.getResource("cd").as(OntClass.class);
			if (res.hasSuperClass(mdrDatabase.getVocabulary().EnumeratedConceptualDomain)) {
				cdList.add(new EnumeratedConceptualDomainImpl(res,
						mdrDatabase));
			} else {
				cdList.add(new NonEnumeratedConceptualDomainImpl(res,
						mdrDatabase));
			}

		}
	} finally {
		qexec.close();
	}
	return cdList;
}
 

@Override
public List<? super DataElementResource> searchDataElement(String keyword,
		String contextURI, TextSearchType searchType, int limit, int offset) {
	List<DataElementResource> dataElementList = new ArrayList<DataElementResource>();
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_PF)
			.append(PREFIX_RDFS)
			.append("SELECT ?de FROM <")
			.append(MDRDatabase.BASE_URI)
			.append("> WHERE {")
			.append("?de rdfs:subClassOf mdr:DataElement .")
			.append("?de mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextTerminologicalEntry ?te .")
			.append("?te mdr:containingTerminologicalEntryLanguage ?ls .")
			.append("?ls mdr:containingNameEntry ?designation .")
			.append("?designation mdr:name ?name .");
	if (!Util.isNull(contextURI)) {
		queryString.append("?aic mdr:administeredItemContextContext <")
				.append(contextURI).append("> .");
	}
	if (keyword.matches("\\s*")) {
		return dataElementList;
	}
	if (searchType == null || searchType.equals(TextSearchType.Exact)) {
		queryString.append(exactMatchKeyword(keyword));
	}

	else if (searchType.equals(TextSearchType.WildCard)) {
		queryString.append(atLeastOneKeyword(keyword));
	}

	else {
		queryString.append(allWordsKeyword(keyword));
	}
	queryString.append(" .} ORDER BY ?score LIMIT ").append(limit)
			.append(" OFFSET ").append(offset);

	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			DataElementResource de = new DataElementImpl(
					qs.getResource("de"), mdrDatabase);
			dataElementList.add(de);
		}
	} finally {
		qexec.close();
	}
	return dataElementList;
}
 

@Override
public int getNumberOfDataElementSearch(String keyword, String contextURI,
		TextSearchType searchType) {
	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_PF)
			.append(PREFIX_RDFS)
			.append("SELECT (COUNT (DISTINCT ?de) as ?count) FROM <")
			.append(MDRDatabase.BASE_URI)
			.append("> WHERE {")
			.append("?de rdfs:subClassOf mdr:DataElement .")
			.append("?de mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextTerminologicalEntry ?te .")
			.append("?te mdr:containingTerminologicalEntryLanguage ?ls .")
			.append("?ls mdr:containingNameEntry ?designation .")
			.append("?designation mdr:name ?name .");
	if (!Util.isNull(contextURI)) {
		queryString.append("?aic mdr:administeredItemContextContext <")
				.append(contextURI).append("> .");
	}
	if (keyword.matches("\\s*")) {
		return 0;
	}
	if (searchType == null || searchType.equals(TextSearchType.Exact)) {
		queryString.append(exactMatchKeyword(keyword));
	}

	else if (searchType.equals(TextSearchType.WildCard)) {
		queryString.append(atLeastOneKeyword(keyword));
	}

	else {
		queryString.append(allWordsKeyword(keyword));
	}
	queryString.append(" .}");

	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());
	int size = 0;
	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			size = qs.getLiteral("count").getInt();
		}
	} finally {
		qexec.close();
	}
	return size;
}
 

public List<? super ValueDomainResource> getValueDomainsOfContext(
		String contextURI, Integer limit, Integer offset) {
	List<ValueDomainResource> valueDomainResourceList = new ArrayList<ValueDomainResource>();

	StringBuilder queryString = new StringBuilder(PREFIX_MDR)
			.append(PREFIX_RDFS).append("SELECT ?vd FROM <")
			.append(MDRDatabase.BASE_URI).append("> WHERE {")
			.append("?vdClass rdfs:subClassOf mdr:ValueDomain .")
			.append("?vd rdfs:subClassOf mdr:vdClass . ")
			.append("?vd mdr:having ?aic .")
			.append("?aic mdr:administeredItemContextContext <")
			.append(contextURI).append("> .").append("}");
	if (limit != null && offset != null) {
		queryString.append(" ORDER BY ?de ").append(" LIMIT ")
				.append(limit).append(" OFFSET ").append(offset);
	}
	QueryExecution qexec = this.createQueryExecution(
			queryString.toString(), this.mdrDatabase.getOntModel());

	try {
		ResultSet rs = qexec.execSelect();
		while (rs.hasNext()) {
			QuerySolution qs = rs.next();
			// here conceptualDomain is checked whether its enumerated or
			// not, proper instantiation is done
			OntClass res = mdrDatabase.getOntModel().getOntClass(
					qs.getResource("cd").getURI());
			if (res.hasSuperClass(mdrDatabase.getVocabulary().EnumeratedValueDomain)) {
				valueDomainResourceList.add(new EnumeratedValueDomainImpl(
						res, mdrDatabase));
			} else {
				valueDomainResourceList
						.add(new NonEnumeratedValueDomainImpl(res,
								mdrDatabase));
			}
		}
	} finally {
		qexec.close();
	}
	return valueDomainResourceList;
}
 

@Override
public Object execute(Map<String, EdmLiteral> parameters) throws ODataException
{
   EdmLiteral query_lit = parameters.remove("query");
   // Olingo2 checks for presence of non-nullable parameters for us!
   String query_s = query_lit.getLiteral();
   Query query = QueryFactory.create(query_s);
   if (!(query.isSelectType() || query.isDescribeType()))
   {
      throw new InvalidOperationException(query.getQueryType());
   }

   DrbCortexModel cortexmodel;
   try
   {
      cortexmodel = DrbCortexModel.getDefaultModel();
   }
   catch (IOException ex)
   {
      throw new RuntimeException(ex);
   }

   Model model = cortexmodel.getCortexModel().getOntModel();

   QueryExecution qexec = null;
   // FIXME: QueryExecution in newer versions of Jena (post apache incubation) implement AutoClosable.
   try
   {
      qexec = QueryExecutionFactory.create(query, model);
      if (query.isSelectType())
      {
         ResultSet results = qexec.execSelect();
         return ResultSetFormatter.asXMLString(results);
      }
      else
      {
         Model description = qexec.execDescribe();
         // newer version of Jena have the RIOT package for I/O
         StringWriter strwrt = new StringWriter();
         Abbreviated abb = new Abbreviated();
         abb.write(description, strwrt, null);
         return strwrt.toString();
      }
   }
   finally
   {
      if (qexec != null)
      {
         qexec.close();
      }
   }
}