restconf/restconf-nb-rfc8040/src/main/java/org/opendaylight/restconf/nb/rfc8040/rests/services/impl/RestconfDataServiceImpl.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.restconf.nb.rfc8040.rests.services.impl;
   9
  10 import static java.util.Objects.requireNonNull;
  11 import static org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfDataServiceConstant.PostPutQueryParameters.INSERT;
  12 import static org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfDataServiceConstant.PostPutQueryParameters.POINT;
  13 import static org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants.NOTIFICATION_STREAM;
  14 import static org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants.STREAMS_PATH;
  15 import static org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants.STREAM_ACCESS_PATH_PART;
  16 import static org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants.STREAM_LOCATION_PATH_PART;
  17 import static org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants.STREAM_PATH;
  18 import static org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfStreamsConstants.STREAM_PATH_PART;
  19
  20 import com.google.common.collect.ImmutableList;
  21 import java.net.URI;
  22 import java.time.Clock;
  23 import java.time.LocalDateTime;
  24 import java.time.format.DateTimeFormatter;
  25 import java.util.List;
  26 import java.util.Map.Entry;
  27 import java.util.Optional;
  28 import java.util.concurrent.ExecutionException;
  29 import javax.ws.rs.Path;
  30 import javax.ws.rs.WebApplicationException;
  31 import javax.ws.rs.core.Response;
  32 import javax.ws.rs.core.UriInfo;
  33 import org.eclipse.jdt.annotation.Nullable;
  34 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  35 import org.opendaylight.mdsal.dom.api.DOMActionResult;
  36 import org.opendaylight.mdsal.dom.api.DOMActionService;
  37 import org.opendaylight.mdsal.dom.api.DOMDataBroker;
  38 import org.opendaylight.mdsal.dom.api.DOMMountPoint;
  39 import org.opendaylight.mdsal.dom.api.DOMMountPointService;
  40 import org.opendaylight.mdsal.dom.api.DOMSchemaService;
  41 import org.opendaylight.restconf.common.context.InstanceIdentifierContext;
  42 import org.opendaylight.restconf.common.context.NormalizedNodeContext;
  43 import org.opendaylight.restconf.common.context.WriterParameters;
  44 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  45 import org.opendaylight.restconf.common.errors.RestconfError;
  46 import org.opendaylight.restconf.common.errors.RestconfError.ErrorTag;
  47 import org.opendaylight.restconf.common.errors.RestconfError.ErrorType;
  48 import org.opendaylight.restconf.common.patch.PatchContext;
  49 import org.opendaylight.restconf.common.patch.PatchStatusContext;
  50 import org.opendaylight.restconf.nb.rfc8040.Rfc8040;
  51 import org.opendaylight.restconf.nb.rfc8040.handlers.SchemaContextHandler;
  52 import org.opendaylight.restconf.nb.rfc8040.rests.services.api.RestconfDataService;
  53 import org.opendaylight.restconf.nb.rfc8040.rests.services.api.RestconfStreamsSubscriptionService;
  54 import org.opendaylight.restconf.nb.rfc8040.rests.transactions.MdsalRestconfStrategy;
  55 import org.opendaylight.restconf.nb.rfc8040.rests.transactions.RestconfStrategy;
  56 import org.opendaylight.restconf.nb.rfc8040.rests.transactions.RestconfTransaction;
  57 import org.opendaylight.restconf.nb.rfc8040.rests.utils.DeleteDataTransactionUtil;
  58 import org.opendaylight.restconf.nb.rfc8040.rests.utils.PatchDataTransactionUtil;
  59 import org.opendaylight.restconf.nb.rfc8040.rests.utils.PlainPatchDataTransactionUtil;
  60 import org.opendaylight.restconf.nb.rfc8040.rests.utils.PostDataTransactionUtil;
  61 import org.opendaylight.restconf.nb.rfc8040.rests.utils.PutDataTransactionUtil;
  62 import org.opendaylight.restconf.nb.rfc8040.rests.utils.ReadDataTransactionUtil;
  63 import org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfDataServiceConstant;
  64 import org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfDataServiceConstant.PostPutQueryParameters.Insert;
  65 import org.opendaylight.restconf.nb.rfc8040.rests.utils.RestconfInvokeOperationsUtil;
  66 import org.opendaylight.restconf.nb.rfc8040.streams.Configuration;
  67 import org.opendaylight.restconf.nb.rfc8040.streams.listeners.NotificationListenerAdapter;
  68 import org.opendaylight.restconf.nb.rfc8040.utils.mapping.RestconfMappingNodeUtil;
  69 import org.opendaylight.restconf.nb.rfc8040.utils.parser.ParserIdentifier;
  70 import org.opendaylight.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  71 import org.opendaylight.yangtools.concepts.Immutable;
  72 import org.opendaylight.yangtools.yang.common.QName;
  73 import org.opendaylight.yangtools.yang.common.Revision;
  74 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  75 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  76 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  77 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  78 import org.opendaylight.yangtools.yang.model.api.ActionDefinition;
  79 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  80 import org.opendaylight.yangtools.yang.model.api.NotificationDefinition;
  81 import org.opendaylight.yangtools.yang.model.api.SchemaNode;
  82 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
  83 import org.slf4j.Logger;
  84 import org.slf4j.LoggerFactory;
  85
  86 /**
  87  * Implementation of {@link RestconfDataService}.
  88  */
  89 @Path("/")
  90 public class RestconfDataServiceImpl implements RestconfDataService {
  91     // FIXME: we should be able to interpret 'point' and refactor this class into a behavior
  92     private static final class QueryParams implements Immutable {
  93         final @Nullable String point;
  94         final @Nullable Insert insert;
  95
  96         QueryParams(final @Nullable Insert insert, final @Nullable String point) {
  97             this.insert = insert;
  98             this.point = point;
  99         }
 100     }
 101
 102     private static final Logger LOG = LoggerFactory.getLogger(RestconfDataServiceImpl.class);
 103     private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("yyyy-MMM-dd HH:mm:ss");
 104
 105     private final RestconfStreamsSubscriptionService delegRestconfSubscrService;
 106     private final SchemaContextHandler schemaContextHandler;
 107     private final MdsalRestconfStrategy restconfStrategy;
 108     private final DOMMountPointService mountPointService;
 109     private final SubscribeToStreamUtil streamUtils;
 110     private final DOMActionService actionService;
 111
 112     public RestconfDataServiceImpl(final SchemaContextHandler schemaContextHandler,
 113             final DOMDataBroker dataBroker, final DOMMountPointService  mountPointService,
 114             final RestconfStreamsSubscriptionService delegRestconfSubscrService,
 115             final DOMActionService actionService, final Configuration configuration) {
 116         this.schemaContextHandler = requireNonNull(schemaContextHandler);
 117         this.restconfStrategy = new MdsalRestconfStrategy(dataBroker);
 118         this.mountPointService = requireNonNull(mountPointService);
 119         this.delegRestconfSubscrService = requireNonNull(delegRestconfSubscrService);
 120         this.actionService = requireNonNull(actionService);
 121         streamUtils = configuration.isUseSSE() ? SubscribeToStreamUtil.serverSentEvents()
 122                 : SubscribeToStreamUtil.webSockets();
 123     }
 124
 125     @Override
 126     public Response readData(final UriInfo uriInfo) {
 127         return readData(null, uriInfo);
 128     }
 129
 130     @Override
 131     public Response readData(final String identifier, final UriInfo uriInfo) {
 132         final EffectiveModelContext schemaContextRef = this.schemaContextHandler.get();
 133         final InstanceIdentifierContext<?> instanceIdentifier = ParserIdentifier.toInstanceIdentifier(
 134                 identifier, schemaContextRef, Optional.of(mountPointService));
 135         final WriterParameters parameters = ReadDataTransactionUtil.parseUriParameters(instanceIdentifier, uriInfo);
 136
 137         final DOMMountPoint mountPoint = instanceIdentifier.getMountPoint();
 138         final RestconfStrategy strategy = getRestconfStrategy(mountPoint);
 139         final NormalizedNode node;
 140         if (parameters.getFieldPaths() != null && !parameters.getFieldPaths().isEmpty()) {
 141             node = ReadDataTransactionUtil.readData(parameters.getContent(), instanceIdentifier.getInstanceIdentifier(),
 142                     strategy, parameters.getWithDefault(), schemaContextRef, parameters.getFieldPaths());
 143         } else {
 144             node = readData(identifier, parameters.getContent(), instanceIdentifier.getInstanceIdentifier(), strategy,
 145                     parameters.getWithDefault(), schemaContextRef, uriInfo);
 146         }
 147         // FIXME: this is utter craziness, refactor it properly!
 148         if (identifier != null && identifier.contains(STREAM_PATH) && identifier.contains(STREAM_ACCESS_PATH_PART)
 149                 && identifier.contains(STREAM_LOCATION_PATH_PART)) {
 150             final String value = (String) node.body();
 151             final String streamName = value.substring(value.indexOf(NOTIFICATION_STREAM + '/'));
 152             this.delegRestconfSubscrService.subscribeToStream(streamName, uriInfo);
 153         }
 154         if (node == null) {
 155             throw new RestconfDocumentedException(
 156                     "Request could not be completed because the relevant data model content does not exist",
 157                     RestconfError.ErrorType.PROTOCOL,
 158                     RestconfError.ErrorTag.DATA_MISSING);
 159         }
 160
 161         if (parameters.getContent().equals(RestconfDataServiceConstant.ReadData.ALL)
 162                     || parameters.getContent().equals(RestconfDataServiceConstant.ReadData.CONFIG)) {
 163             final QName type = node.getIdentifier().getNodeType();
 164             return Response.status(200)
 165                     .entity(new NormalizedNodeContext(instanceIdentifier, node, parameters))
 166                     .header("ETag", '"' + type.getModule().getRevision().map(Revision::toString).orElse(null)
 167                         + "-" + type.getLocalName() + '"')
 168                     .header("Last-Modified", FORMATTER.format(LocalDateTime.now(Clock.systemUTC())))
 169                     .build();
 170         }
 171
 172         return Response.status(200).entity(new NormalizedNodeContext(instanceIdentifier, node, parameters)).build();
 173     }
 174
 175     /**
 176      * Read specific type of data from data store via transaction and if identifier read data from
 177      * streams then put streams from actual schema context to datastore.
 178      *
 179      * @param identifier    identifier of data to read
 180      * @param content       type of data to read (config, state, all)
 181      * @param strategy      {@link RestconfStrategy} - object that perform the actual DS operations
 182      * @param withDefa      value of with-defaults parameter
 183      * @param schemaContext schema context
 184      * @param uriInfo       uri info
 185      * @return {@link NormalizedNode}
 186      */
 187     private NormalizedNode readData(final String identifier, final String content,
 188             final YangInstanceIdentifier path, final RestconfStrategy strategy, final String withDefa,
 189             final EffectiveModelContext schemaContext, final UriInfo uriInfo) {
 190         if (identifier != null && identifier.contains(STREAMS_PATH) && !identifier.contains(STREAM_PATH_PART)) {
 191             createAllYangNotificationStreams(strategy, schemaContext, uriInfo);
 192         }
 193         return ReadDataTransactionUtil.readData(content, path, strategy, withDefa, schemaContext);
 194     }
 195
 196     private void createAllYangNotificationStreams(final RestconfStrategy strategy,
 197             final EffectiveModelContext schemaContext, final UriInfo uriInfo) {
 198         final RestconfTransaction transaction = strategy.prepareWriteExecution();
 199
 200         for (final NotificationDefinition notificationDefinition : schemaContext.getNotifications()) {
 201             final NotificationListenerAdapter notifiStreamXML =
 202                 CreateStreamUtil.createYangNotifiStream(notificationDefinition, schemaContext,
 203                     NotificationOutputType.XML);
 204             final NotificationListenerAdapter notifiStreamJSON =
 205                 CreateStreamUtil.createYangNotifiStream(notificationDefinition, schemaContext,
 206                     NotificationOutputType.JSON);
 207             writeNotificationStreamToDatastore(schemaContext, uriInfo, transaction, notifiStreamXML);
 208             writeNotificationStreamToDatastore(schemaContext, uriInfo, transaction, notifiStreamJSON);
 209         }
 210         try {
 211             transaction.commit().get();
 212         } catch (final InterruptedException | ExecutionException e) {
 213             throw new RestconfDocumentedException("Problem while putting data to DS.", e);
 214         }
 215     }
 216
 217     private void writeNotificationStreamToDatastore(final EffectiveModelContext schemaContext,
 218             final UriInfo uriInfo, final RestconfTransaction transaction, final NotificationListenerAdapter listener) {
 219         final URI uri = streamUtils.prepareUriByStreamName(uriInfo, listener.getStreamName());
 220         final MapEntryNode mapToStreams = RestconfMappingNodeUtil.mapYangNotificationStreamByIetfRestconfMonitoring(
 221                 listener.getSchemaPath().lastNodeIdentifier(), schemaContext.getNotifications(), null,
 222                 listener.getOutputType(), uri);
 223
 224         transaction.merge(LogicalDatastoreType.OPERATIONAL,
 225             Rfc8040.restconfStateStreamPath(mapToStreams.getIdentifier()), mapToStreams);
 226     }
 227
 228     @Override
 229     public Response putData(final String identifier, final NormalizedNodeContext payload, final UriInfo uriInfo) {
 230         requireNonNull(payload);
 231
 232         final QueryParams checkedParms = checkQueryParameters(uriInfo);
 233
 234         final InstanceIdentifierContext<? extends SchemaNode> iid = payload.getInstanceIdentifierContext();
 235
 236         PutDataTransactionUtil.validInputData(iid.getSchemaNode(), payload);
 237         PutDataTransactionUtil.validTopLevelNodeName(iid.getInstanceIdentifier(), payload);
 238         PutDataTransactionUtil.validateListKeysEqualityInPayloadAndUri(payload);
 239
 240         final DOMMountPoint mountPoint = payload.getInstanceIdentifierContext().getMountPoint();
 241         final EffectiveModelContext ref = mountPoint == null
 242                 ? this.schemaContextHandler.get() : modelContext(mountPoint);
 243
 244         final RestconfStrategy strategy = getRestconfStrategy(mountPoint);
 245         return PutDataTransactionUtil.putData(payload, ref, strategy, checkedParms.insert, checkedParms.point);
 246     }
 247
 248     private static QueryParams checkQueryParameters(final UriInfo uriInfo) {
 249         boolean insertUsed = false;
 250         boolean pointUsed = false;
 251         Insert insert = null;
 252         String point = null;
 253
 254         for (final Entry<String, List<String>> entry : uriInfo.getQueryParameters().entrySet()) {
 255             switch (entry.getKey()) {
 256                 case INSERT:
 257                     if (insertUsed) {
 258                         throw new RestconfDocumentedException("Insert parameter can be used only once.",
 259                             RestconfError.ErrorType.PROTOCOL, RestconfError.ErrorTag.BAD_ELEMENT);
 260                     }
 261
 262                     insertUsed = true;
 263                     final String str = entry.getValue().get(0);
 264                     insert = Insert.forValue(str);
 265                     if (insert == null) {
 266                         throw new RestconfDocumentedException("Unrecognized insert parameter value '" + str + "'",
 267                             RestconfError.ErrorType.PROTOCOL, RestconfError.ErrorTag.BAD_ELEMENT);
 268                     }
 269                     break;
 270                 case POINT:
 271                     if (pointUsed) {
 272                         throw new RestconfDocumentedException("Point parameter can be used only once.",
 273                             RestconfError.ErrorType.PROTOCOL, RestconfError.ErrorTag.BAD_ELEMENT);
 274                     }
 275
 276                     pointUsed = true;
 277                     point = entry.getValue().get(0);
 278                     break;
 279                 default:
 280                     throw new RestconfDocumentedException("Bad parameter for post: " + entry.getKey(),
 281                             RestconfError.ErrorType.PROTOCOL, RestconfError.ErrorTag.BAD_ELEMENT);
 282             }
 283         }
 284
 285         checkQueryParams(insertUsed, pointUsed, insert);
 286         return new QueryParams(insert, point);
 287     }
 288
 289     private static void checkQueryParams(final boolean insertUsed, final boolean pointUsed, final Insert insert) {
 290         if (pointUsed) {
 291             if (!insertUsed) {
 292                 throw new RestconfDocumentedException("Point parameter can't be used without Insert parameter.",
 293                     RestconfError.ErrorType.PROTOCOL, RestconfError.ErrorTag.BAD_ELEMENT);
 294             }
 295
 296             if (insert != Insert.BEFORE && insert != Insert.AFTER) {
 297                 throw new RestconfDocumentedException(
 298                     "Point parameter can be used only with 'after' or 'before' values of Insert parameter.",
 299                     RestconfError.ErrorType.PROTOCOL, RestconfError.ErrorTag.BAD_ELEMENT);
 300             }
 301         }
 302     }
 303
 304     @Override
 305     public Response postData(final String identifier, final NormalizedNodeContext payload, final UriInfo uriInfo) {
 306         return postData(payload, uriInfo);
 307     }
 308
 309     @Override
 310     public Response postData(final NormalizedNodeContext payload, final UriInfo uriInfo) {
 311         requireNonNull(payload);
 312         if (payload.getInstanceIdentifierContext().getSchemaNode() instanceof ActionDefinition) {
 313             return invokeAction(payload);
 314         }
 315
 316         final QueryParams checkedParms = checkQueryParameters(uriInfo);
 317         final DOMMountPoint mountPoint = payload.getInstanceIdentifierContext().getMountPoint();
 318         final RestconfStrategy strategy = getRestconfStrategy(mountPoint);
 319         return PostDataTransactionUtil.postData(uriInfo, payload, strategy,
 320                 getSchemaContext(mountPoint), checkedParms.insert, checkedParms.point);
 321     }
 322
 323     @Override
 324     public Response deleteData(final String identifier) {
 325         final InstanceIdentifierContext<?> instanceIdentifier = ParserIdentifier.toInstanceIdentifier(
 326                 identifier, this.schemaContextHandler.get(), Optional.of(mountPointService));
 327
 328         final DOMMountPoint mountPoint = instanceIdentifier.getMountPoint();
 329         final RestconfStrategy strategy = getRestconfStrategy(mountPoint);
 330         return DeleteDataTransactionUtil.deleteData(strategy, instanceIdentifier.getInstanceIdentifier());
 331     }
 332
 333     @Override
 334     public PatchStatusContext patchData(final String identifier, final PatchContext context, final UriInfo uriInfo) {
 335         return patchData(context, uriInfo);
 336     }
 337
 338     @Override
 339     public PatchStatusContext patchData(final PatchContext context, final UriInfo uriInfo) {
 340         final DOMMountPoint mountPoint = requireNonNull(context).getInstanceIdentifierContext().getMountPoint();
 341         final RestconfStrategy strategy = getRestconfStrategy(mountPoint);
 342         return PatchDataTransactionUtil.patchData(context, strategy, getSchemaContext(mountPoint));
 343     }
 344
 345     @Override
 346     public Response patchData(final String identifier, final NormalizedNodeContext payload, final UriInfo uriInfo) {
 347         requireNonNull(payload);
 348
 349         final InstanceIdentifierContext<? extends SchemaNode> iid = payload
 350                 .getInstanceIdentifierContext();
 351
 352         PutDataTransactionUtil.validInputData(iid.getSchemaNode(), payload);
 353         PutDataTransactionUtil.validTopLevelNodeName(iid.getInstanceIdentifier(), payload);
 354         PutDataTransactionUtil.validateListKeysEqualityInPayloadAndUri(payload);
 355
 356         final DOMMountPoint mountPoint = payload.getInstanceIdentifierContext().getMountPoint();
 357         final EffectiveModelContext ref = mountPoint == null
 358                 ? this.schemaContextHandler.get() : modelContext(mountPoint);
 359         final RestconfStrategy strategy = getRestconfStrategy(mountPoint);
 360
 361         return PlainPatchDataTransactionUtil.patchData(payload, strategy, ref);
 362     }
 363
 364     private EffectiveModelContext getSchemaContext(final DOMMountPoint mountPoint) {
 365         return mountPoint == null ? schemaContextHandler.get() : modelContext(mountPoint);
 366     }
 367
 368     // FIXME: why is this synchronized?
 369     public synchronized RestconfStrategy getRestconfStrategy(final DOMMountPoint mountPoint) {
 370         if (mountPoint == null) {
 371             return restconfStrategy;
 372         }
 373
 374         return RestconfStrategy.forMountPoint(mountPoint).orElseThrow(() -> {
 375             LOG.warn("Mount point {} does not expose a suitable access interface", mountPoint.getIdentifier());
 376             return new RestconfDocumentedException("Could not find a supported access interface in mount point "
 377                 + mountPoint.getIdentifier());
 378         });
 379     }
 380
 381     /**
 382      * Invoke Action operation.
 383      *
 384      * @param payload {@link NormalizedNodeContext} - the body of the operation
 385      * @return {@link NormalizedNodeContext} wrapped in {@link Response}
 386      */
 387     public Response invokeAction(final NormalizedNodeContext payload) {
 388         final InstanceIdentifierContext<?> context = payload.getInstanceIdentifierContext();
 389         final DOMMountPoint mountPoint = context.getMountPoint();
 390         final Absolute schemaPath = Absolute.of(ImmutableList.copyOf(context.getSchemaNode().getPath()
 391             .getPathFromRoot()));
 392         final YangInstanceIdentifier yangIIdContext = context.getInstanceIdentifier();
 393         final NormalizedNode data = payload.getData();
 394
 395         if (yangIIdContext.isEmpty()
 396             && !RestconfDataServiceConstant.NETCONF_BASE_QNAME.equals(data.getIdentifier().getNodeType())) {
 397             throw new RestconfDocumentedException("Instance identifier need to contain at least one path argument",
 398                 ErrorType.PROTOCOL, ErrorTag.MALFORMED_MESSAGE);
 399         }
 400
 401         final DOMActionResult response;
 402         final EffectiveModelContext schemaContextRef;
 403         if (mountPoint != null) {
 404             response = RestconfInvokeOperationsUtil.invokeActionViaMountPoint(mountPoint, (ContainerNode) data,
 405                 schemaPath, yangIIdContext);
 406             schemaContextRef = modelContext(mountPoint);
 407         } else {
 408             response = RestconfInvokeOperationsUtil.invokeAction((ContainerNode) data, schemaPath,
 409                 this.actionService, yangIIdContext);
 410             schemaContextRef = this.schemaContextHandler.get();
 411         }
 412         final DOMActionResult result = RestconfInvokeOperationsUtil.checkActionResponse(response);
 413
 414         ActionDefinition resultNodeSchema = null;
 415         ContainerNode resultData = null;
 416         if (result != null) {
 417             final Optional<ContainerNode> optOutput = result.getOutput();
 418             if (optOutput.isPresent()) {
 419                 resultData = optOutput.get();
 420                 resultNodeSchema = (ActionDefinition) context.getSchemaNode();
 421             }
 422         }
 423
 424         if (resultData != null && resultData.isEmpty()) {
 425             throw new WebApplicationException(Response.Status.NO_CONTENT);
 426         }
 427
 428         return Response.status(200).entity(new NormalizedNodeContext(new InstanceIdentifierContext<>(yangIIdContext,
 429                 resultNodeSchema, mountPoint, schemaContextRef), resultData)).build();
 430     }
 431
 432     private static EffectiveModelContext modelContext(final DOMMountPoint mountPoint) {
 433         return mountPoint.getService(DOMSchemaService.class)
 434             .flatMap(svc -> Optional.ofNullable(svc.getGlobalContext()))
 435             .orElse(null);
 436     }
 437 }