Java tutorial
/******************************************************************************* * Copyright (c) 2015 Eclipse RDF4J contributors, Aduna, and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Distribution License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/org/documents/edl-v10.php. *******************************************************************************/ package org.eclipse.rdf4j.http.server.repository.statements; import static javax.servlet.http.HttpServletResponse.SC_BAD_REQUEST; import static javax.servlet.http.HttpServletResponse.SC_SERVICE_UNAVAILABLE; import static javax.servlet.http.HttpServletResponse.SC_UNSUPPORTED_MEDIA_TYPE; import static org.eclipse.rdf4j.http.protocol.Protocol.BASEURI_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.BINDING_PREFIX; import static org.eclipse.rdf4j.http.protocol.Protocol.CONTEXT_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.INCLUDE_INFERRED_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.INSERT_GRAPH_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.OBJECT_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.PREDICATE_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.QUERY_LANGUAGE_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.REMOVE_GRAPH_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.SUBJECT_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.USING_GRAPH_PARAM_NAME; import static org.eclipse.rdf4j.http.protocol.Protocol.USING_NAMED_GRAPH_PARAM_NAME; import java.io.IOException; import java.io.InputStream; import java.util.Enumeration; import java.util.HashMap; import java.util.Map; import java.util.Objects; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.io.IOUtils; import org.eclipse.rdf4j.common.webapp.util.HttpServerUtil; import org.eclipse.rdf4j.common.webapp.views.EmptySuccessView; import org.eclipse.rdf4j.http.protocol.Protocol; import org.eclipse.rdf4j.http.protocol.error.ErrorInfo; import org.eclipse.rdf4j.http.protocol.error.ErrorType; import org.eclipse.rdf4j.http.protocol.transaction.TransactionReader; import org.eclipse.rdf4j.http.protocol.transaction.operations.TransactionOperation; import org.eclipse.rdf4j.http.server.ClientHTTPException; import org.eclipse.rdf4j.http.server.HTTPException; import org.eclipse.rdf4j.http.server.ProtocolUtil; import org.eclipse.rdf4j.http.server.ServerHTTPException; import org.eclipse.rdf4j.http.server.repository.RepositoryInterceptor; import org.eclipse.rdf4j.model.IRI; import org.eclipse.rdf4j.model.Resource; import org.eclipse.rdf4j.model.Value; import org.eclipse.rdf4j.model.ValueFactory; import org.eclipse.rdf4j.query.MalformedQueryException; import org.eclipse.rdf4j.query.QueryInterruptedException; import org.eclipse.rdf4j.query.QueryLanguage; import org.eclipse.rdf4j.query.Update; import org.eclipse.rdf4j.query.UpdateExecutionException; import org.eclipse.rdf4j.query.impl.SimpleDataset; import org.eclipse.rdf4j.repository.Repository; import org.eclipse.rdf4j.repository.RepositoryConnection; import org.eclipse.rdf4j.repository.RepositoryException; import org.eclipse.rdf4j.rio.RDFFormat; import org.eclipse.rdf4j.rio.RDFParseException; import org.eclipse.rdf4j.rio.RDFWriterFactory; import org.eclipse.rdf4j.rio.RDFWriterRegistry; import org.eclipse.rdf4j.rio.Rio; import org.eclipse.rdf4j.rio.UnsupportedRDFormatException; import org.eclipse.rdf4j.rio.helpers.BasicParserSettings; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.context.ApplicationContextException; import org.springframework.web.servlet.ModelAndView; import org.springframework.web.servlet.mvc.AbstractController; import org.xml.sax.SAXException; import org.xml.sax.SAXParseException; /** * Handles requests for manipulating the statements in a repository. * * @author Herko ter Horst * @author Arjohn Kampman */ public class StatementsController extends AbstractController { private Logger logger = LoggerFactory.getLogger(this.getClass()); public StatementsController() throws ApplicationContextException { setSupportedMethods(new String[] { METHOD_GET, METHOD_POST, METHOD_HEAD, "PUT", "DELETE" }); } @Override protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response) throws Exception { ModelAndView result; Repository repository = RepositoryInterceptor.getRepository(request); String reqMethod = request.getMethod(); if (METHOD_GET.equals(reqMethod)) { logger.info("GET statements"); result = getExportStatementsResult(repository, request, response); } else if (METHOD_HEAD.equals(reqMethod)) { logger.info("HEAD statements"); result = getExportStatementsResult(repository, request, response); } else if (METHOD_POST.equals(reqMethod)) { String mimeType = HttpServerUtil.getMIMEType(request.getContentType()); if (Protocol.TXN_MIME_TYPE.equals(mimeType)) { logger.info("POST transaction to repository"); result = getTransactionResultResult(repository, request, response); } else if (Protocol.SPARQL_UPDATE_MIME_TYPE.equals(mimeType) || request.getParameterMap().containsKey(Protocol.UPDATE_PARAM_NAME)) { logger.info("POST SPARQL update request to repository"); result = getSparqlUpdateResult(repository, request, response); } else { logger.info("POST data to repository"); result = getAddDataResult(repository, request, response, false); } } else if ("PUT".equals(reqMethod)) { logger.info("PUT data in repository"); result = getAddDataResult(repository, request, response, true); } else if ("DELETE".equals(reqMethod)) { logger.info("DELETE data from repository"); result = getDeleteDataResult(repository, request, response); } else { throw new ClientHTTPException(HttpServletResponse.SC_METHOD_NOT_ALLOWED, "Method not allowed: " + reqMethod); } return result; } private ModelAndView getSparqlUpdateResult(Repository repository, HttpServletRequest request, HttpServletResponse response) throws ServerHTTPException, ClientHTTPException, HTTPException { ProtocolUtil.logRequestParameters(request); String mimeType = HttpServerUtil.getMIMEType(request.getContentType()); String sparqlUpdateString; if (Protocol.SPARQL_UPDATE_MIME_TYPE.equals(mimeType)) { // The query should be the entire body try { sparqlUpdateString = IOUtils.toString(request.getReader()); } catch (IOException e) { throw new ClientHTTPException(SC_BAD_REQUEST, "Error reading request message body", e); } if (sparqlUpdateString.isEmpty()) sparqlUpdateString = null; } else { sparqlUpdateString = request.getParameterValues(Protocol.UPDATE_PARAM_NAME)[0]; } // default query language is SPARQL QueryLanguage queryLn = QueryLanguage.SPARQL; String queryLnStr = request.getParameter(QUERY_LANGUAGE_PARAM_NAME); logger.debug("query language param = {}", queryLnStr); if (queryLnStr != null) { queryLn = QueryLanguage.valueOf(queryLnStr); if (queryLn == null) { throw new ClientHTTPException(SC_BAD_REQUEST, "Unknown query language: " + queryLnStr); } } String baseURI = request.getParameter(Protocol.BASEURI_PARAM_NAME); // determine if inferred triples should be included in query evaluation boolean includeInferred = ProtocolUtil.parseBooleanParam(request, INCLUDE_INFERRED_PARAM_NAME, true); // build a dataset, if specified String[] defaultRemoveGraphURIs = request.getParameterValues(REMOVE_GRAPH_PARAM_NAME); String[] defaultInsertGraphURIs = request.getParameterValues(INSERT_GRAPH_PARAM_NAME); String[] defaultGraphURIs = request.getParameterValues(USING_GRAPH_PARAM_NAME); String[] namedGraphURIs = request.getParameterValues(USING_NAMED_GRAPH_PARAM_NAME); SimpleDataset dataset = null; if (defaultRemoveGraphURIs != null || defaultInsertGraphURIs != null || defaultGraphURIs != null || namedGraphURIs != null) { dataset = new SimpleDataset(); } if (defaultRemoveGraphURIs != null) { for (String graphURI : defaultRemoveGraphURIs) { try { IRI uri = createURIOrNull(repository, graphURI); dataset.addDefaultRemoveGraph(uri); } catch (IllegalArgumentException e) { throw new ClientHTTPException(SC_BAD_REQUEST, "Illegal URI for default remove graph: " + graphURI); } } } if (defaultInsertGraphURIs != null && defaultInsertGraphURIs.length > 0) { String graphURI = defaultInsertGraphURIs[0]; try { IRI uri = createURIOrNull(repository, graphURI); dataset.setDefaultInsertGraph(uri); } catch (IllegalArgumentException e) { throw new ClientHTTPException(SC_BAD_REQUEST, "Illegal URI for default insert graph: " + graphURI); } } if (defaultGraphURIs != null) { for (String defaultGraphURI : defaultGraphURIs) { try { IRI uri = createURIOrNull(repository, defaultGraphURI); dataset.addDefaultGraph(uri); } catch (IllegalArgumentException e) { throw new ClientHTTPException(SC_BAD_REQUEST, "Illegal URI for default graph: " + defaultGraphURI); } } } if (namedGraphURIs != null) { for (String namedGraphURI : namedGraphURIs) { try { IRI uri = createURIOrNull(repository, namedGraphURI); dataset.addNamedGraph(uri); } catch (IllegalArgumentException e) { throw new ClientHTTPException(SC_BAD_REQUEST, "Illegal URI for named graph: " + namedGraphURI); } } } final int maxQueryTime = ProtocolUtil.parseTimeoutParam(request); try (RepositoryConnection repositoryCon = RepositoryInterceptor.getRepositoryConnection(request)) { Update update = repositoryCon.prepareUpdate(queryLn, sparqlUpdateString, baseURI); update.setIncludeInferred(includeInferred); update.setMaxExecutionTime(maxQueryTime); if (dataset != null) { update.setDataset(dataset); } // determine if any variable bindings have been set on this // update. @SuppressWarnings("unchecked") Enumeration<String> parameterNames = request.getParameterNames(); while (parameterNames.hasMoreElements()) { String parameterName = parameterNames.nextElement(); if (parameterName.startsWith(BINDING_PREFIX) && parameterName.length() > BINDING_PREFIX.length()) { String bindingName = parameterName.substring(BINDING_PREFIX.length()); Value bindingValue = ProtocolUtil.parseValueParam(request, parameterName, repository.getValueFactory()); update.setBinding(bindingName, bindingValue); } } update.execute(); return new ModelAndView(EmptySuccessView.getInstance()); } catch (QueryInterruptedException e) { throw new ServerHTTPException(SC_SERVICE_UNAVAILABLE, "update execution took too long"); } catch (UpdateExecutionException e) { if (e.getCause() != null && e.getCause() instanceof HTTPException) { // custom signal from the backend, throw as HTTPException // directly // (see SES-1016). throw (HTTPException) e.getCause(); } else { throw new ServerHTTPException("Repository update error: " + e.getMessage(), e); } } catch (RepositoryException e) { if (e.getCause() != null && e.getCause() instanceof HTTPException) { // custom signal from the backend, throw as HTTPException // directly // (see SES-1016). throw (HTTPException) e.getCause(); } else { throw new ServerHTTPException("Repository update error: " + e.getMessage(), e); } } catch (MalformedQueryException e) { ErrorInfo errInfo = new ErrorInfo(ErrorType.MALFORMED_QUERY, e.getMessage()); throw new ClientHTTPException(SC_BAD_REQUEST, errInfo.toString()); } } private IRI createURIOrNull(Repository repository, String graphURI) { if ("null".equals(graphURI)) return null; return repository.getValueFactory().createIRI(graphURI); } /** * Get all statements and export them as RDF. * * @return a model and view for exporting the statements. */ private ModelAndView getExportStatementsResult(Repository repository, HttpServletRequest request, HttpServletResponse response) throws ClientHTTPException { ProtocolUtil.logRequestParameters(request); ValueFactory vf = repository.getValueFactory(); Resource subj = ProtocolUtil.parseResourceParam(request, SUBJECT_PARAM_NAME, vf); IRI pred = ProtocolUtil.parseURIParam(request, PREDICATE_PARAM_NAME, vf); Value obj = ProtocolUtil.parseValueParam(request, OBJECT_PARAM_NAME, vf); Resource[] contexts = ProtocolUtil.parseContextParam(request, CONTEXT_PARAM_NAME, vf); boolean useInferencing = ProtocolUtil.parseBooleanParam(request, INCLUDE_INFERRED_PARAM_NAME, true); RDFWriterFactory rdfWriterFactory = ProtocolUtil.getAcceptableService(request, response, RDFWriterRegistry.getInstance()); Map<String, Object> model = new HashMap<String, Object>(); model.put(ExportStatementsView.SUBJECT_KEY, subj); model.put(ExportStatementsView.PREDICATE_KEY, pred); model.put(ExportStatementsView.OBJECT_KEY, obj); model.put(ExportStatementsView.CONTEXTS_KEY, contexts); model.put(ExportStatementsView.USE_INFERENCING_KEY, Boolean.valueOf(useInferencing)); model.put(ExportStatementsView.FACTORY_KEY, rdfWriterFactory); model.put(ExportStatementsView.HEADERS_ONLY, METHOD_HEAD.equals(request.getMethod())); return new ModelAndView(ExportStatementsView.getInstance(), model); } /** * Process several actions as a transaction. */ private ModelAndView getTransactionResultResult(Repository repository, HttpServletRequest request, HttpServletResponse response) throws IOException, ClientHTTPException, ServerHTTPException, HTTPException { InputStream in = request.getInputStream(); try (RepositoryConnection repositoryCon = RepositoryInterceptor.getRepositoryConnection(request)) { logger.debug("Processing transaction..."); TransactionReader reader = new TransactionReader(); Iterable<? extends TransactionOperation> txn = reader.parse(in); repositoryCon.begin(); for (TransactionOperation op : txn) { op.execute(repositoryCon); } repositoryCon.commit(); logger.debug("Transaction processed "); return new ModelAndView(EmptySuccessView.getInstance()); } catch (SAXParseException e) { ErrorInfo errInfo = new ErrorInfo(ErrorType.MALFORMED_DATA, e.getMessage()); throw new ClientHTTPException(SC_BAD_REQUEST, errInfo.toString()); } catch (SAXException e) { throw new ServerHTTPException("Failed to parse transaction data: " + e.getMessage(), e); } catch (IOException e) { throw new ServerHTTPException("Failed to read data: " + e.getMessage(), e); } catch (RepositoryException e) { if (e.getCause() != null && e.getCause() instanceof HTTPException) { // custom signal from the backend, throw as HTTPException // directly // (see SES-1016). throw (HTTPException) e.getCause(); } else { throw new ServerHTTPException("Repository update error: " + e.getMessage(), e); } } } /** * Upload data to the repository. */ private ModelAndView getAddDataResult(Repository repository, HttpServletRequest request, HttpServletResponse response, boolean replaceCurrent) throws IOException, ServerHTTPException, ClientHTTPException, HTTPException { ProtocolUtil.logRequestParameters(request); String mimeType = HttpServerUtil.getMIMEType(request.getContentType()); RDFFormat rdfFormat = Rio.getParserFormatForMIMEType(mimeType).orElseThrow( () -> new ClientHTTPException(SC_UNSUPPORTED_MEDIA_TYPE, "Unsupported MIME type: " + mimeType)); ValueFactory vf = repository.getValueFactory(); Resource[] contexts = ProtocolUtil.parseContextParam(request, CONTEXT_PARAM_NAME, vf); IRI baseURI = ProtocolUtil.parseURIParam(request, BASEURI_PARAM_NAME, vf); final boolean preserveNodeIds = ProtocolUtil.parseBooleanParam(request, Protocol.PRESERVE_BNODE_ID_PARAM_NAME, false); if (baseURI == null) { baseURI = vf.createIRI("foo:bar"); logger.info("no base URI specified, using dummy '{}'", baseURI); } InputStream in = request.getInputStream(); try (RepositoryConnection repositoryCon = RepositoryInterceptor.getRepositoryConnection(request)) { repositoryCon.begin(); if (preserveNodeIds) { repositoryCon.getParserConfig().set(BasicParserSettings.PRESERVE_BNODE_IDS, true); } if (replaceCurrent) { repositoryCon.clear(contexts); } repositoryCon.add(in, baseURI.toString(), rdfFormat, contexts); repositoryCon.commit(); return new ModelAndView(EmptySuccessView.getInstance()); } catch (UnsupportedRDFormatException e) { throw new ClientHTTPException(SC_UNSUPPORTED_MEDIA_TYPE, "No RDF parser available for format " + rdfFormat.getName()); } catch (RDFParseException e) { ErrorInfo errInfo = new ErrorInfo(ErrorType.MALFORMED_DATA, e.getMessage()); throw new ClientHTTPException(SC_BAD_REQUEST, errInfo.toString()); } catch (IOException e) { throw new ServerHTTPException("Failed to read data: " + e.getMessage(), e); } catch (RepositoryException e) { if (e.getCause() != null && e.getCause() instanceof HTTPException) { // custom signal from the backend, throw as HTTPException // directly // (see SES-1016). throw (HTTPException) e.getCause(); } else { throw new ServerHTTPException("Repository update error: " + e.getMessage(), e); } } } /** * Delete data from the repository. */ private ModelAndView getDeleteDataResult(Repository repository, HttpServletRequest request, HttpServletResponse response) throws ServerHTTPException, ClientHTTPException, HTTPException { ProtocolUtil.logRequestParameters(request); ValueFactory vf = repository.getValueFactory(); Resource subj = ProtocolUtil.parseResourceParam(request, SUBJECT_PARAM_NAME, vf); IRI pred = ProtocolUtil.parseURIParam(request, PREDICATE_PARAM_NAME, vf); Value obj = ProtocolUtil.parseValueParam(request, OBJECT_PARAM_NAME, vf); Resource[] contexts = ProtocolUtil.parseContextParam(request, CONTEXT_PARAM_NAME, vf); try (RepositoryConnection repositoryCon = RepositoryInterceptor.getRepositoryConnection(request)) { repositoryCon.remove(subj, pred, obj, contexts); return new ModelAndView(EmptySuccessView.getInstance()); } catch (RepositoryException e) { if (e.getCause() != null && e.getCause() instanceof HTTPException) { // custom signal from the backend, throw as HTTPException // directly // (see SES-1016). throw (HTTPException) e.getCause(); } else { throw new ServerHTTPException("Repository update error: " + e.getMessage(), e); } } } }