Java tutorial
package com.linkedpipes.plugin.loader.dcatAp11ToCkanBatch; import java.io.IOException; import java.nio.charset.Charset; import java.text.Normalizer; import java.util.HashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Map.Entry; import com.linkedpipes.etl.component.api.service.ProgressReport; import org.apache.http.client.methods.CloseableHttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.CloseableHttpClient; import org.apache.http.impl.client.HttpClientBuilder; import org.apache.http.impl.client.HttpClients; import org.apache.http.impl.client.LaxRedirectStrategy; import org.apache.http.message.BasicHeader; import org.apache.http.util.EntityUtils; import org.json.JSONArray; import org.json.JSONObject; import org.openrdf.model.Value; import org.openrdf.model.vocabulary.DCTERMS; import org.openrdf.model.vocabulary.FOAF; import org.openrdf.model.vocabulary.SKOS; import org.openrdf.query.BindingSet; import org.openrdf.query.QueryLanguage; import org.openrdf.query.QueryResults; import org.openrdf.query.TupleQuery; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.linkedpipes.etl.dataunit.sesame.api.rdf.SingleGraphDataUnit; import org.openrdf.query.TupleQueryResult; import com.linkedpipes.etl.component.api.Component; import com.linkedpipes.etl.component.api.service.ExceptionFactory; import com.linkedpipes.etl.executor.api.v1.exception.LpException; import org.openrdf.query.impl.SimpleDataset; /** * * @author Klmek Jakub */ public final class DcatAp11ToCkanBatch implements Component.Sequential { private static final Logger LOG = LoggerFactory.getLogger(DcatAp11ToCkanBatch.class); @Component.InputPort(id = "Metadata") public SingleGraphDataUnit metadata; @Component.InputPort(id = "Codelists", optional = true) public SingleGraphDataUnit codelists; @Component.Configuration public DcatAp11ToCkanBatchConfiguration configuration; @Component.Inject public ExceptionFactory exceptionFactory; @Component.Inject public ProgressReport progressReport; private CloseableHttpClient queryClient = HttpClientBuilder.create() .setRedirectStrategy(new LaxRedirectStrategy()).build(); private CloseableHttpClient createClient = HttpClientBuilder.create() .setRedirectStrategy(new LaxRedirectStrategy()).build(); private CloseableHttpClient postClient = HttpClients.createDefault(); private String apiURI; private String fixKeyword(String keyword) { return keyword.replace(",", "").replace(".", "").replace("/", "-").replace(":", "-").replace(";", "-") .replace("", "paragraf"); } private Map<String, String> getOrganizations() { CloseableHttpResponse queryResponse = null; List<String> organizationList = new LinkedList<>(); Map<String, String> organizations = new HashMap<>(); HttpGet httpGetOrg = new HttpGet(apiURI + "/organization_list"); LOG.debug("Querying CKAN for organizations"); try { queryResponse = queryClient.execute(httpGetOrg); if (queryResponse.getStatusLine().getStatusCode() == 200) { JSONArray response = new JSONObject(EntityUtils.toString(queryResponse.getEntity())) .getJSONArray("result"); for (Object o : response) { organizationList.add(o.toString()); } LOG.info("Organization list downloaded, found " + organizationList.size() + " organizations."); } else { String ent = EntityUtils.toString(queryResponse.getEntity()); LOG.info("Organizations not downloaded: " + ent); } } catch (Exception e) { LOG.error(e.getLocalizedMessage(), e); } finally { if (queryResponse != null) { try { queryResponse.close(); } catch (IOException e) { LOG.error(e.getLocalizedMessage(), e); } } } LOG.debug("Querying for organization details."); for (String organization : organizationList) { HttpGet httpGetOrgDetail = new HttpGet(apiURI + "/organization_show?id=" + organization); try { queryResponse = queryClient.execute(httpGetOrgDetail); if (queryResponse.getStatusLine().getStatusCode() == 200) { LOG.info("Organization " + organization + " downloaded"); JSONObject response = new JSONObject(EntityUtils.toString(queryResponse.getEntity())) .getJSONObject("result"); JSONArray org_extras = response.getJSONArray("extras"); for (Object extra : org_extras) { String extraKey = ((JSONObject) extra).getString("key"); String extraValue = ((JSONObject) extra).getString("value"); if (extraKey.equals("uri")) { organizations.put(extraValue, organization); break; } } } else { String ent = EntityUtils.toString(queryResponse.getEntity()); LOG.info("Organization " + organization + " not downloaded: " + ent); } } catch (Exception e) { LOG.error(e.getLocalizedMessage(), e); } finally { if (queryResponse != null) { try { queryResponse.close(); } catch (IOException e) { LOG.error(e.getLocalizedMessage(), e); } } } } return organizations; } @Override public void execute() throws LpException { apiURI = configuration.getApiUri(); if (apiURI == null || apiURI.isEmpty() || configuration.getApiKey() == null || configuration.getApiKey().isEmpty()) { throw exceptionFactory.failure("Missing required settings."); } Map<String, String> organizations = getOrganizations(); LOG.debug("Querying metadata for datasets"); LinkedList<String> datasets = new LinkedList<>(); for (Map<String, Value> map : executeSelectQuery( "SELECT ?d WHERE {?d a <" + DcatAp11ToCkanBatchVocabulary.DCAT_DATASET_CLASS + ">}")) { datasets.add(map.get("d").stringValue()); } int current = 0; int total = datasets.size(); LOG.info("Found " + total + " datasets"); progressReport.start(total); for (String datasetURI : datasets) { current++; CloseableHttpResponse queryResponse = null; LOG.info("Processing dataset " + current + "/" + total + ": " + datasetURI); String datasetID = executeSimpleSelectQuery("SELECT ?did WHERE {<" + datasetURI + "> <" + DcatAp11ToCkanBatchVocabulary.LODCZCKAN_DATASET_ID + "> ?did }", "did"); if (datasetID.isEmpty()) { LOG.warn("Dataset " + datasetURI + " has missing CKAN ID"); continue; } boolean datasetExists = false; Map<String, String> resUrlIdMap = new HashMap<>(); Map<String, String> resDistroIdMap = new HashMap<>(); Map<String, JSONObject> resourceList = new HashMap<>(); LOG.debug("Querying for the dataset " + datasetID + " in CKAN"); HttpGet httpGet = new HttpGet(apiURI + "/package_show?id=" + datasetID); try { queryResponse = queryClient.execute(httpGet); if (queryResponse.getStatusLine().getStatusCode() == 200) { LOG.debug("Dataset found"); datasetExists = true; JSONObject response = new JSONObject(EntityUtils.toString(queryResponse.getEntity())) .getJSONObject("result"); JSONArray resourcesArray = response.getJSONArray("resources"); for (int i = 0; i < resourcesArray.length(); i++) { String id = resourcesArray.getJSONObject(i).getString("id"); resourceList.put(id, resourcesArray.getJSONObject(i)); String url = resourcesArray.getJSONObject(i).getString("url"); resUrlIdMap.put(url, id); if (resourcesArray.getJSONObject(i).has("distro_url")) { String distro = resourcesArray.getJSONObject(i).getString("distro_url"); resDistroIdMap.put(distro, id); } } } else { String ent = EntityUtils.toString(queryResponse.getEntity()); LOG.debug("Dataset not found: " + ent); } } catch (Exception e) { LOG.error(e.getLocalizedMessage(), e); } finally { if (queryResponse != null) { try { queryResponse.close(); } catch (IOException e) { LOG.error(e.getLocalizedMessage(), e); } } } LinkedList<String> keywords = new LinkedList<>(); for (Map<String, Value> map : executeSelectQuery( "SELECT ?keyword WHERE {<" + datasetURI + "> <" + DcatAp11ToCkanBatchVocabulary.DCAT_KEYWORD + "> ?keyword FILTER(LANGMATCHES(LANG(?keyword), \"" + configuration.getLoadLanguage() + "\"))}")) { keywords.add(map.get("keyword").stringValue()); } String publisher_uri = executeSimpleSelectQuery("SELECT ?publisher_uri WHERE {<" + datasetURI + "> <" + DCTERMS.PUBLISHER + "> ?publisher_uri }", "publisher_uri"); String publisher_name = executeSimpleSelectQuery( "SELECT ?publisher_name WHERE {<" + datasetURI + "> <" + DCTERMS.PUBLISHER + ">/<" + FOAF.NAME + "> ?publisher_name FILTER(LANGMATCHES(LANG(?publisher_name), \"" + configuration.getLoadLanguage() + "\"))}", "publisher_name"); if (!organizations.containsKey(publisher_uri)) { LOG.debug("Creating organization " + publisher_uri); JSONObject root = new JSONObject(); if (publisher_name == null || publisher_name.isEmpty()) { throw exceptionFactory.failure("Organization has no name: " + publisher_uri); } root.put("title", publisher_name); String orgname = Normalizer.normalize(publisher_name, Normalizer.Form.NFD) .replaceAll("\\P{InBasic_Latin}", "").replace(' ', '-').replace('.', '-').toLowerCase(); root.put("name", orgname); JSONArray org_extras = new JSONArray(); org_extras.put(new JSONObject().put("key", "uri").put("value", publisher_uri)); root.put("extras", org_extras); HttpPost httpPost = new HttpPost(apiURI + "/organization_create"); httpPost.addHeader(new BasicHeader("Authorization", configuration.getApiKey())); String json = root.toString(); httpPost.setEntity(new StringEntity(json, Charset.forName("utf-8"))); CloseableHttpResponse response = null; try { response = postClient.execute(httpPost); if (response.getStatusLine().getStatusCode() == 200) { LOG.debug("Organization created OK"); //LOG.info("Response: " + EntityUtils.toString(response.getEntity())); organizations.put(publisher_uri, orgname); } else if (response.getStatusLine().getStatusCode() == 409) { String ent = EntityUtils.toString(response.getEntity()); LOG.error("Organization conflict: " + ent); throw exceptionFactory.failure("Organization conflict: " + ent); } else { String ent = EntityUtils.toString(response.getEntity()); LOG.error("Response:" + ent); throw exceptionFactory.failure("Error creating organization: " + ent); } } catch (Exception e) { LOG.error(e.getLocalizedMessage(), e); } finally { if (response != null) { try { response.close(); } catch (IOException e) { LOG.error(e.getLocalizedMessage(), e); throw exceptionFactory.failure("Error creating dataset"); } } } } LOG.debug("Creating JSON"); JSONObject root = new JSONObject(); JSONArray tags = new JSONArray(); for (String keyword : keywords) { String safekeyword = fixKeyword(keyword); if (safekeyword.length() >= 2) { tags.put(new JSONObject().put("name", safekeyword)); } } root.put("tags", tags); JSONArray resources = new JSONArray(); if (!datasetID.isEmpty()) { root.put("name", datasetID); } String title = executeSimpleSelectQuery("SELECT ?title WHERE {<" + datasetURI + "> <" + DCTERMS.TITLE + "> ?title FILTER(LANGMATCHES(LANG(?title), \"" + configuration.getLoadLanguage() + "\"))}", "title"); if (!title.isEmpty()) { root.put("title", title); } String description = executeSimpleSelectQuery("SELECT ?description WHERE {<" + datasetURI + "> <" + DCTERMS.DESCRIPTION + "> ?description FILTER(LANGMATCHES(LANG(?description), \"" + configuration.getLoadLanguage() + "\"))}", "description"); if (!description.isEmpty()) { root.put("notes", description); } String contactPoint = executeSimpleSelectQuery("SELECT ?contact WHERE {<" + datasetURI + "> <" + DcatAp11ToCkanBatchVocabulary.DCAT_CONTACT_POINT + ">/<" + DcatAp11ToCkanBatchVocabulary.VCARD_HAS_EMAIL + "> ?contact }", "contact"); if (!contactPoint.isEmpty()) { root.put("maintainer_email", contactPoint); } String curatorName = executeSimpleSelectQuery( "SELECT ?name WHERE {<" + datasetURI + "> <" + DcatAp11ToCkanBatchVocabulary.DCAT_CONTACT_POINT + ">/<" + DcatAp11ToCkanBatchVocabulary.VCARD_FN + "> ?name }", "name"); if (!curatorName.isEmpty()) { root.put("maintainer", curatorName); } String issued = executeSimpleSelectQuery( "SELECT ?issued WHERE {<" + datasetURI + "> <" + DCTERMS.ISSUED + "> ?issued }", "issued"); if (!issued.isEmpty()) { root.put("metadata_created", issued); } String modified = executeSimpleSelectQuery( "SELECT ?modified WHERE {<" + datasetURI + "> <" + DCTERMS.MODIFIED + "> ?modified }", "modified"); if (!modified.isEmpty()) { root.put("metadata_modified", modified); } if (configuration.getProfile().equals(DcatAp11ToCkanBatchVocabulary.PROFILES_NKOD.stringValue())) { if (!publisher_uri.isEmpty()) { root.put("publisher_uri", publisher_uri); } if (!publisher_name.isEmpty()) { root.put("publisher_name", publisher_name); } String periodicity = executeSimpleSelectQuery("SELECT ?periodicity WHERE {<" + datasetURI + "> <" + DCTERMS.ACCRUAL_PERIODICITY + "> ?periodicity }", "periodicity"); if (!periodicity.isEmpty()) { root.put("frequency", periodicity); } String temporalStart = executeSimpleSelectQuery( "SELECT ?temporalStart WHERE {<" + datasetURI + "> <" + DCTERMS.TEMPORAL + ">/<" + DcatAp11ToCkanBatchVocabulary.SCHEMA_STARTDATE + "> ?temporalStart }", "temporalStart"); if (!temporalStart.isEmpty()) { root.put("temporal_start", temporalStart); } String temporalEnd = executeSimpleSelectQuery( "SELECT ?temporalEnd WHERE {<" + datasetURI + "> <" + DCTERMS.TEMPORAL + ">/<" + DcatAp11ToCkanBatchVocabulary.SCHEMA_ENDDATE + "> ?temporalEnd }", "temporalEnd"); if (!temporalEnd.isEmpty()) { root.put("temporal_end", temporalEnd); } String schemaURL = executeSimpleSelectQuery( "SELECT ?schema WHERE {<" + datasetURI + "> <" + FOAF.PAGE + "> ?schema }", "schema"); if (!schemaURL.isEmpty()) { root.put("schema", schemaURL); } String spatial = executeSimpleSelectQuery( "SELECT ?spatial WHERE {<" + datasetURI + "> <" + DCTERMS.SPATIAL + "> ?spatial }", "spatial"); if (!spatial.isEmpty()) { root.put("spatial_uri", spatial); } LinkedList<String> themes = new LinkedList<>(); for (Map<String, Value> map : executeSelectQuery("SELECT ?theme WHERE {<" + datasetURI + "> <" + DcatAp11ToCkanBatchVocabulary.DCAT_THEME + "> ?theme }")) { themes.add(map.get("theme").stringValue()); } String concatThemes = ""; for (String theme : themes) { concatThemes += theme + " "; } if (!concatThemes.isEmpty()) root.put("theme", concatThemes); } //Distributions LinkedList<String> distributions = new LinkedList<>(); for (Map<String, Value> map : executeSelectQuery("SELECT ?distribution WHERE {<" + datasetURI + "> <" + DcatAp11ToCkanBatchVocabulary.DCAT_DISTRIBUTION + "> ?distribution }")) { distributions.add(map.get("distribution").stringValue()); } for (String distribution : distributions) { JSONObject distro = new JSONObject(); String dtitle = executeSimpleSelectQuery("SELECT ?title WHERE {<" + distribution + "> <" + DCTERMS.TITLE + "> ?title FILTER(LANGMATCHES(LANG(?title), \"" + configuration.getLoadLanguage() + "\"))}", "title"); if (!dtitle.isEmpty()) { distro.put("name", dtitle); } String ddescription = executeSimpleSelectQuery("SELECT ?description WHERE {<" + distribution + "> <" + DCTERMS.DESCRIPTION + "> ?description FILTER(LANGMATCHES(LANG(?description), \"" + configuration.getLoadLanguage() + "\"))}", "description"); if (!ddescription.isEmpty()) { distro.put("description", ddescription); } //DCAT-AP v1.1: has to be am IRI from http://publications.europa.eu/mdr/authority/file-type/index.html String dformat = executeSimpleSelectQuery( "SELECT ?format WHERE {<" + distribution + "> <" + DCTERMS.FORMAT + "> ?format }", "format"); if (!dformat.isEmpty() && codelists != null) { String formatlabel = executeSimpleCodelistSelectQuery( "SELECT ?formatlabel WHERE {<" + dformat + "> <" + SKOS.PREF_LABEL + "> ?formatlabel FILTER(LANGMATCHES(LANG(?formatlabel), \"en\"))}", "formatlabel"); if (!formatlabel.isEmpty()) { distro.put("format", formatlabel); } } String dwnld = executeSimpleSelectQuery("SELECT ?dwnld WHERE {<" + distribution + "> <" + DcatAp11ToCkanBatchVocabulary.DCAT_DOWNLOADURL + "> ?dwnld }", "dwnld"); String access = executeSimpleSelectQuery("SELECT ?acc WHERE {<" + distribution + "> <" + DcatAp11ToCkanBatchVocabulary.DCAT_ACCESSURL + "> ?acc }", "acc"); //we prefer downloadURL, but only accessURL is mandatory if (dwnld == null || dwnld.isEmpty()) { dwnld = access; if (dwnld == null || dwnld.isEmpty()) { LOG.warn("Empty download and access URLs: " + datasetURI); continue; } } if (!dwnld.isEmpty()) { distro.put("url", dwnld); } if (!distribution.isEmpty()) { distro.put("distro_url", distribution); } distro.put("resource_type", "file"); if (resDistroIdMap.containsKey(distribution)) { String id = resDistroIdMap.get(distribution); distro.put("id", id); resourceList.remove(id); } else if (resUrlIdMap.containsKey(dwnld)) { String id = resUrlIdMap.get(dwnld); distro.put("id", id); resourceList.remove(id); } String dissued = executeSimpleSelectQuery( "SELECT ?issued WHERE {<" + distribution + "> <" + DCTERMS.ISSUED + "> ?issued }", "issued"); if (!dissued.isEmpty()) { distro.put("created", dissued); } String dmodified = executeSimpleSelectQuery( "SELECT ?modified WHERE {<" + distribution + "> <" + DCTERMS.MODIFIED + "> ?modified }", "modified"); if (!dmodified.isEmpty()) { distro.put("last_modified", dmodified); } if (configuration.getProfile().equals(DcatAp11ToCkanBatchVocabulary.PROFILES_NKOD.stringValue())) { String dtemporalStart = executeSimpleSelectQuery( "SELECT ?temporalStart WHERE {<" + distribution + "> <" + DCTERMS.TEMPORAL + ">/<" + DcatAp11ToCkanBatchVocabulary.SCHEMA_STARTDATE + "> ?temporalStart }", "temporalStart"); if (!dtemporalStart.isEmpty()) { distro.put("temporal_start", dtemporalStart); } String dtemporalEnd = executeSimpleSelectQuery( "SELECT ?temporalEnd WHERE {<" + distribution + "> <" + DCTERMS.TEMPORAL + ">/<" + DcatAp11ToCkanBatchVocabulary.SCHEMA_ENDDATE + "> ?temporalEnd }", "temporalEnd"); if (!dtemporalEnd.isEmpty()) { distro.put("temporal_end", dtemporalEnd); } String dspatial = executeSimpleSelectQuery( "SELECT ?spatial WHERE {<" + distribution + "> <" + DCTERMS.SPATIAL + "> ?spatial }", "spatial"); if (!dspatial.isEmpty()) { root.put("spatial_uri", dspatial); } String dschemaURL = executeSimpleSelectQuery( "SELECT ?schema WHERE {<" + distribution + "> <" + DCTERMS.CONFORMS_TO + "> ?schema }", "schema"); if (!dschemaURL.isEmpty()) { distro.put("describedBy", dschemaURL); } String dlicense = executeSimpleSelectQuery( "SELECT ?license WHERE {<" + distribution + "> <" + DCTERMS.LICENSE + "> ?license }", "license"); if (!dlicense.isEmpty()) { distro.put("license_link", dlicense); } String dmimetype = executeSimpleSelectQuery("SELECT ?format WHERE {<" + distribution + "> <" + DcatAp11ToCkanBatchVocabulary.DCAT_MEDIATYPE + "> ?format }", "format"); if (!dmimetype.isEmpty()) { distro.put("mimetype", dmimetype.replaceAll(".*\\/([^\\/]+\\/[^\\/]+)", "$1")); } } resources.put(distro); } //Add the remaining distributions that were not updated but existed in the original dataset for (Entry<String, JSONObject> resource : resourceList.entrySet()) { resources.put(resource.getValue()); } root.put("resources", resources); //Create new dataset if (!datasetExists) { JSONObject createRoot = new JSONObject(); CloseableHttpResponse response = null; createRoot.put("name", datasetID); createRoot.put("title", title); createRoot.put("owner_org", organizations.get(publisher_uri)); LOG.debug("Creating dataset in CKAN"); HttpPost httpPost = new HttpPost(apiURI + "/package_create?id=" + datasetID); httpPost.addHeader(new BasicHeader("Authorization", configuration.getApiKey())); String json = createRoot.toString(); LOG.debug("Creating dataset with: " + json); httpPost.setEntity(new StringEntity(json, Charset.forName("utf-8"))); try { response = createClient.execute(httpPost); if (response.getStatusLine().getStatusCode() == 200) { LOG.debug("Dataset created OK"); //LOG.info("Response: " + EntityUtils.toString(response.getEntity())); } else if (response.getStatusLine().getStatusCode() == 409) { String ent = EntityUtils.toString(response.getEntity()); LOG.error("Dataset already exists: " + ent); throw exceptionFactory.failure("Dataset already exists"); } else { String ent = EntityUtils.toString(response.getEntity()); LOG.error("Response:" + ent); throw exceptionFactory.failure("Error creating dataset"); } } catch (Exception e) { LOG.error(e.getLocalizedMessage(), e); } finally { if (response != null) { try { response.close(); } catch (IOException e) { LOG.error(e.getLocalizedMessage(), e); throw exceptionFactory.failure("Error creating dataset"); } } } } //Update existing dataset String json = root.toString(); LOG.debug("Posting to CKAN"); HttpPost httpPost = new HttpPost(apiURI + "/package_update?id=" + datasetID); httpPost.addHeader(new BasicHeader("Authorization", configuration.getApiKey())); LOG.debug(json); httpPost.setEntity(new StringEntity(json, Charset.forName("utf-8"))); CloseableHttpResponse response = null; try { response = postClient.execute(httpPost); if (response.getStatusLine().getStatusCode() == 200) { //LOG.info("Response:" + EntityUtils.toString(response.getEntity())); } else { String ent = EntityUtils.toString(response.getEntity()); LOG.error("Response:" + ent); throw exceptionFactory.failure("Error updating dataset"); } } catch (Exception e) { LOG.error(e.getLocalizedMessage(), e); } finally { if (response != null) { try { response.close(); } catch (IOException e) { LOG.error(e.getLocalizedMessage(), e); throw exceptionFactory.failure("Error updating dataset"); } } } progressReport.entryProcessed(); } try { queryClient.close(); createClient.close(); postClient.close(); } catch (IOException e) { LOG.error(e.getLocalizedMessage(), e); } progressReport.done(); } private String executeSimpleSelectQuery(final String queryAsString, String bindingName) throws LpException { return metadata.execute((connection) -> { final TupleQuery preparedQuery = connection.prepareTupleQuery(QueryLanguage.SPARQL, queryAsString); final SimpleDataset dataset = new SimpleDataset(); dataset.addDefaultGraph(metadata.getGraph()); preparedQuery.setDataset(dataset); // final BindingSet binding = QueryResults.singleResult(preparedQuery.evaluate()); if (binding == null) { return ""; } else { return binding.getValue(bindingName).stringValue(); } }); } private String executeSimpleCodelistSelectQuery(final String queryAsString, String bindingName) throws LpException { return codelists.execute((connection) -> { final TupleQuery preparedQuery = connection.prepareTupleQuery(QueryLanguage.SPARQL, queryAsString); final SimpleDataset dataset = new SimpleDataset(); dataset.addDefaultGraph(codelists.getGraph()); preparedQuery.setDataset(dataset); // final BindingSet binding = QueryResults.singleResult(preparedQuery.evaluate()); if (binding == null) { return ""; } else { return binding.getValue(bindingName).stringValue(); } }); } private List<Map<String, Value>> executeSelectQuery(final String queryAsString) throws LpException { return metadata.execute((connection) -> { final List<Map<String, Value>> output = new LinkedList<>(); final TupleQuery preparedQuery = connection.prepareTupleQuery(QueryLanguage.SPARQL, queryAsString); final SimpleDataset dataset = new SimpleDataset(); dataset.addDefaultGraph(metadata.getGraph()); preparedQuery.setDataset(dataset); // TupleQueryResult result = preparedQuery.evaluate(); while (result.hasNext()) { final BindingSet binding = result.next(); final Map<String, Value> row = new HashMap<>(); binding.forEach((item) -> { row.put(item.getName(), item.getValue()); }); output.add(row); } return output; }); } }