restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/rest/impl/RestconfDocumentedExceptionMapper.java

   1 /*
   2  * Copyright (c) 2014 Brocade Communications 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
   9 package org.opendaylight.netconf.sal.rest.impl;
  10
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.base.Throwables;
  13 import com.google.common.collect.Iterables;
  14 import com.google.gson.stream.JsonWriter;
  15 import java.io.ByteArrayOutputStream;
  16 import java.io.IOException;
  17 import java.io.OutputStreamWriter;
  18 import java.io.UnsupportedEncodingException;
  19 import java.net.URI;
  20 import java.nio.charset.StandardCharsets;
  21 import java.util.Iterator;
  22 import java.util.List;
  23 import javax.ws.rs.core.Context;
  24 import javax.ws.rs.core.HttpHeaders;
  25 import javax.ws.rs.core.MediaType;
  26 import javax.ws.rs.core.Response;
  27 import javax.ws.rs.ext.ExceptionMapper;
  28 import javax.ws.rs.ext.Provider;
  29 import javax.xml.XMLConstants;
  30 import javax.xml.stream.FactoryConfigurationError;
  31 import javax.xml.stream.XMLOutputFactory;
  32 import javax.xml.stream.XMLStreamException;
  33 import javax.xml.stream.XMLStreamWriter;
  34 import org.opendaylight.netconf.sal.rest.api.Draft02;
  35 import org.opendaylight.netconf.sal.restconf.impl.ControllerContext;
  36 import org.opendaylight.restconf.common.context.InstanceIdentifierContext;
  37 import org.opendaylight.restconf.common.context.NormalizedNodeContext;
  38 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  39 import org.opendaylight.restconf.common.errors.RestconfError;
  40 import org.opendaylight.yangtools.yang.common.QName;
  41 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  42 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifierWithPredicates;
  43 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  44 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  45 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  46 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  47 import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
  48 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  49 import org.opendaylight.yangtools.yang.data.api.schema.stream.ForwardingNormalizedNodeStreamWriter;
  50 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  51 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  52 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
  53 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  54 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  55 import org.opendaylight.yangtools.yang.data.codec.xml.XMLStreamNormalizedNodeStreamWriter;
  56 import org.opendaylight.yangtools.yang.data.impl.schema.Builders;
  57 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
  58 import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.CollectionNodeBuilder;
  59 import org.opendaylight.yangtools.yang.data.impl.schema.builder.api.DataContainerNodeAttrBuilder;
  60 import org.opendaylight.yangtools.yang.model.api.ContainerSchemaNode;
  61 import org.opendaylight.yangtools.yang.model.api.DataNodeContainer;
  62 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
  63 import org.opendaylight.yangtools.yang.model.api.LeafSchemaNode;
  64 import org.opendaylight.yangtools.yang.model.api.ListSchemaNode;
  65 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  66 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  67 import org.slf4j.Logger;
  68 import org.slf4j.LoggerFactory;
  69
  70 /**
  71  * This class defines an ExceptionMapper that handles RestconfDocumentedExceptions thrown by resource implementations
  72  * and translates appropriately to restconf error response as defined in the RESTCONF RFC draft.
  73  *
  74  * @author Thomas Pantelis
  75  */
  76 @Provider
  77 public class RestconfDocumentedExceptionMapper implements ExceptionMapper<RestconfDocumentedException> {
  78
  79     private static final Logger LOG = LoggerFactory.getLogger(RestconfDocumentedExceptionMapper.class);
  80
  81     private static final XMLOutputFactory XML_FACTORY;
  82
  83     static {
  84         XML_FACTORY = XMLOutputFactory.newFactory();
  85         XML_FACTORY.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, true);
  86     }
  87
  88     @Context
  89     private HttpHeaders headers;
  90
  91     @Override
  92     public Response toResponse(final RestconfDocumentedException exception) {
  93
  94         LOG.debug("In toResponse: {}", exception.getMessage());
  95
  96         final List<MediaType> accepts = headers.getAcceptableMediaTypes();
  97         if (accepts != null) {
  98             accepts.remove(MediaType.WILDCARD_TYPE);
  99         }
 100
 101         LOG.debug("Accept headers: {}", accepts);
 102
 103         final MediaType mediaType;
 104         if (accepts != null && accepts.size() > 0) {
 105             mediaType = accepts.get(0); // just pick the first one
 106         } else {
 107             // Default to the content type if there's no Accept header
 108             mediaType = MediaType.APPLICATION_JSON_TYPE;
 109         }
 110
 111         LOG.debug("Using MediaType: {}", mediaType);
 112
 113         final List<RestconfError> errors = exception.getErrors();
 114         if (errors.isEmpty()) {
 115             // We don't actually want to send any content but, if we don't set any content here,
 116             // the tomcat front-end will send back an html error report. To prevent that, set a
 117             // single space char in the entity.
 118
 119             return Response.status(exception.getStatus()).type(MediaType.TEXT_PLAIN_TYPE).entity(" ").build();
 120         }
 121
 122         final int status = errors.iterator().next().getErrorTag().getStatusCode();
 123
 124         final ControllerContext context = ControllerContext.getInstance();
 125         final DataNodeContainer errorsSchemaNode = (DataNodeContainer) context.getRestconfModuleErrorsSchemaNode();
 126
 127         if (errorsSchemaNode == null) {
 128             return Response.status(status).type(MediaType.TEXT_PLAIN_TYPE).entity(exception.getMessage()).build();
 129         }
 130
 131         Preconditions.checkState(errorsSchemaNode instanceof ContainerSchemaNode,
 132                 "Found Errors SchemaNode isn't ContainerNode");
 133         final DataContainerNodeAttrBuilder<NodeIdentifier, ContainerNode> errContBuild =
 134                 Builders.containerBuilder((ContainerSchemaNode) errorsSchemaNode);
 135
 136         final List<DataSchemaNode> schemaList = ControllerContext.findInstanceDataChildrenByName(errorsSchemaNode,
 137                 Draft02.RestConfModule.ERROR_LIST_SCHEMA_NODE);
 138         final DataSchemaNode errListSchemaNode = Iterables.getFirst(schemaList, null);
 139         Preconditions.checkState(
 140                 errListSchemaNode instanceof ListSchemaNode, "Found Error SchemaNode isn't ListSchemaNode");
 141         final CollectionNodeBuilder<MapEntryNode, MapNode> listErorsBuilder = Builders
 142                 .mapBuilder((ListSchemaNode) errListSchemaNode);
 143
 144
 145         for (final RestconfError error : errors) {
 146             listErorsBuilder.withChild(toErrorEntryNode(error, errListSchemaNode));
 147         }
 148         errContBuild.withChild(listErorsBuilder.build());
 149
 150         final NormalizedNodeContext errContext =  new NormalizedNodeContext(new InstanceIdentifierContext<>(null,
 151                 (DataSchemaNode) errorsSchemaNode, null, context.getGlobalSchema()), errContBuild.build());
 152
 153         Object responseBody;
 154         if (mediaType.getSubtype().endsWith("json")) {
 155             responseBody = toJsonResponseBody(errContext, errorsSchemaNode);
 156         } else {
 157             responseBody = toXMLResponseBody(errContext, errorsSchemaNode);
 158         }
 159
 160         return Response.status(status).type(mediaType).entity(responseBody).build();
 161     }
 162
 163     private static MapEntryNode toErrorEntryNode(final RestconfError error, final DataSchemaNode errListSchemaNode) {
 164         Preconditions.checkArgument(errListSchemaNode instanceof ListSchemaNode,
 165                 "errListSchemaNode has to be of type ListSchemaNode");
 166         final ListSchemaNode listStreamSchemaNode = (ListSchemaNode) errListSchemaNode;
 167         final DataContainerNodeAttrBuilder<NodeIdentifierWithPredicates, MapEntryNode> errNodeValues = Builders
 168                 .mapEntryBuilder(listStreamSchemaNode);
 169
 170         List<DataSchemaNode> lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 171                 listStreamSchemaNode, "error-type");
 172         final DataSchemaNode errTypSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 173         Preconditions.checkState(errTypSchemaNode instanceof LeafSchemaNode);
 174         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errTypSchemaNode)
 175                 .withValue(error.getErrorType().getErrorTypeTag()).build());
 176
 177         lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 178                 listStreamSchemaNode, "error-tag");
 179         final DataSchemaNode errTagSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 180         Preconditions.checkState(errTagSchemaNode instanceof LeafSchemaNode);
 181         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errTagSchemaNode)
 182                 .withValue(error.getErrorTag().getTagValue()).build());
 183
 184         if (error.getErrorAppTag() != null) {
 185             lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 186                     listStreamSchemaNode, "error-app-tag");
 187             final DataSchemaNode errAppTagSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 188             Preconditions.checkState(errAppTagSchemaNode instanceof LeafSchemaNode);
 189             errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errAppTagSchemaNode)
 190                     .withValue(error.getErrorAppTag()).build());
 191         }
 192
 193         lsChildDataSchemaNode = ControllerContext.findInstanceDataChildrenByName(
 194                 listStreamSchemaNode, "error-message");
 195         final DataSchemaNode errMsgSchemaNode = Iterables.getFirst(lsChildDataSchemaNode, null);
 196         Preconditions.checkState(errMsgSchemaNode instanceof LeafSchemaNode);
 197         errNodeValues.withChild(Builders.leafBuilder((LeafSchemaNode) errMsgSchemaNode)
 198                 .withValue(error.getErrorMessage()).build());
 199
 200         if (error.getErrorInfo() != null) {
 201             // Oddly, error-info is defined as an empty container in the restconf yang. Apparently the
 202             // intention is for implementors to define their own data content so we'll just treat it as a leaf
 203             // with string data.
 204             errNodeValues.withChild(ImmutableNodes.leafNode(Draft02.RestConfModule.ERROR_INFO_QNAME,
 205                     error.getErrorInfo()));
 206         }
 207
 208         // TODO : find how could we add possible "error-path"
 209
 210         return errNodeValues.build();
 211     }
 212
 213     private static Object toJsonResponseBody(final NormalizedNodeContext errorsNode,
 214                                              final DataNodeContainer errorsSchemaNode) {
 215         final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
 216         NormalizedNode<?, ?> data = errorsNode.getData();
 217         final InstanceIdentifierContext<?> context = errorsNode.getInstanceIdentifierContext();
 218         final DataSchemaNode schema = (DataSchemaNode) context.getSchemaNode();
 219
 220         SchemaPath path = context.getSchemaNode().getPath();
 221         final OutputStreamWriter outputWriter = new OutputStreamWriter(outStream, StandardCharsets.UTF_8);
 222         if (data == null) {
 223             throw new RestconfDocumentedException(Response.Status.NOT_FOUND);
 224         }
 225
 226         boolean isDataRoot = false;
 227         URI initialNs = null;
 228         if (SchemaPath.ROOT.equals(path)) {
 229             isDataRoot = true;
 230         } else {
 231             path = path.getParent();
 232             // FIXME: Add proper handling of reading root.
 233         }
 234         if (!schema.isAugmenting() && !(schema instanceof SchemaContext)) {
 235             initialNs = schema.getQName().getNamespace();
 236         }
 237
 238         final JsonWriter jsonWriter = JsonWriterFactory.createJsonWriter(outputWriter);
 239         final NormalizedNodeStreamWriter jsonStreamWriter = JSONNormalizedNodeStreamWriter.createExclusiveWriter(
 240                 JSONCodecFactory.getShared(context.getSchemaContext()), path, initialNs, jsonWriter);
 241
 242         // We create a delegating writer to special-case error-info as error-info is defined as an empty
 243         // container in the restconf yang schema but we create a leaf node so we can output it. The delegate
 244         // stream writer validates the node type against the schema and thus will expect a LeafSchemaNode but
 245         // the schema has a ContainerSchemaNode so, to avoid an error, we override the leafNode behavior
 246         // for error-info.
 247         final NormalizedNodeStreamWriter streamWriter = new ForwardingNormalizedNodeStreamWriter() {
 248             @Override
 249             protected NormalizedNodeStreamWriter delegate() {
 250                 return jsonStreamWriter;
 251             }
 252
 253             @Override
 254             public void leafNode(final NodeIdentifier name, final Object value) throws IOException {
 255                 if (name.getNodeType().equals(Draft02.RestConfModule.ERROR_INFO_QNAME)) {
 256                     jsonWriter.name(Draft02.RestConfModule.ERROR_INFO_QNAME.getLocalName());
 257                     jsonWriter.value(value.toString());
 258                 } else {
 259                     super.leafNode(name, value);
 260                 }
 261             }
 262         };
 263
 264         final NormalizedNodeWriter nnWriter = NormalizedNodeWriter.forStreamWriter(streamWriter);
 265         try {
 266             if (isDataRoot) {
 267                 writeDataRoot(outputWriter,nnWriter,(ContainerNode) data);
 268             } else {
 269                 if (data instanceof MapEntryNode) {
 270                     data = ImmutableNodes.mapNodeBuilder(data.getNodeType()).withChild((MapEntryNode) data).build();
 271                 }
 272                 nnWriter.write(data);
 273             }
 274             nnWriter.flush();
 275             outputWriter.flush();
 276         } catch (final IOException e) {
 277             LOG.warn("Error writing error response body", e);
 278         }
 279
 280         try {
 281             return outStream.toString(StandardCharsets.UTF_8.name());
 282         } catch (UnsupportedEncodingException e) {
 283             // Shouldn't happen
 284             return "Failure encoding error response: " + e;
 285         }
 286     }
 287
 288     private static Object toXMLResponseBody(final NormalizedNodeContext errorsNode,
 289                                             final DataNodeContainer errorsSchemaNode) {
 290         final InstanceIdentifierContext<?> pathContext = errorsNode.getInstanceIdentifierContext();
 291         final ByteArrayOutputStream outStream = new ByteArrayOutputStream();
 292
 293         final XMLStreamWriter xmlWriter;
 294         try {
 295             xmlWriter = XML_FACTORY.createXMLStreamWriter(outStream, StandardCharsets.UTF_8.name());
 296         } catch (final XMLStreamException e) {
 297             throw new IllegalStateException(e);
 298         } catch (final FactoryConfigurationError e) {
 299             throw new IllegalStateException(e);
 300         }
 301         NormalizedNode<?, ?> data = errorsNode.getData();
 302         SchemaPath schemaPath = pathContext.getSchemaNode().getPath();
 303
 304         boolean isDataRoot = false;
 305         if (SchemaPath.ROOT.equals(schemaPath)) {
 306             isDataRoot = true;
 307         } else {
 308             schemaPath = schemaPath.getParent();
 309         }
 310
 311         final NormalizedNodeStreamWriter xmlStreamWriter = XMLStreamNormalizedNodeStreamWriter.create(xmlWriter,
 312                 pathContext.getSchemaContext(), schemaPath);
 313
 314         // We create a delegating writer to special-case error-info as error-info is defined as an empty
 315         // container in the restconf yang schema but we create a leaf node so we can output it. The delegate
 316         // stream writer validates the node type against the schema and thus will expect a LeafSchemaNode but
 317         // the schema has a ContainerSchemaNode so, to avoid an error, we override the leafNode behavior
 318         // for error-info.
 319         final NormalizedNodeStreamWriter streamWriter = new ForwardingNormalizedNodeStreamWriter() {
 320             @Override
 321             protected NormalizedNodeStreamWriter delegate() {
 322                 return xmlStreamWriter;
 323             }
 324
 325             @Override
 326             public void leafNode(final NodeIdentifier name, final Object value) throws IOException {
 327                 if (name.getNodeType().equals(Draft02.RestConfModule.ERROR_INFO_QNAME)) {
 328                     String ns = Draft02.RestConfModule.ERROR_INFO_QNAME.getNamespace().toString();
 329                     try {
 330                         xmlWriter.writeStartElement(XMLConstants.DEFAULT_NS_PREFIX,
 331                                 Draft02.RestConfModule.ERROR_INFO_QNAME.getLocalName(), ns);
 332                         xmlWriter.writeCharacters(value.toString());
 333                         xmlWriter.writeEndElement();
 334                     } catch (XMLStreamException e) {
 335                         throw new IOException("Error writing error-info", e);
 336                     }
 337                 } else {
 338                     super.leafNode(name, value);
 339                 }
 340             }
 341         };
 342
 343         final NormalizedNodeWriter nnWriter = NormalizedNodeWriter.forStreamWriter(streamWriter);
 344         try {
 345             if (isDataRoot) {
 346                 writeRootElement(xmlWriter, nnWriter, (ContainerNode) data);
 347             } else {
 348                 if (data instanceof MapEntryNode) {
 349                     // Restconf allows returning one list item. We need to wrap it
 350                     // in map node in order to serialize it properly
 351                     data = ImmutableNodes.mapNodeBuilder(data.getNodeType()).addChild((MapEntryNode) data).build();
 352                 }
 353                 nnWriter.write(data);
 354                 nnWriter.flush();
 355             }
 356         } catch (final IOException e) {
 357             LOG.warn("Error writing error response body.", e);
 358         }
 359
 360         try {
 361             return outStream.toString(StandardCharsets.UTF_8.name());
 362         } catch (UnsupportedEncodingException e) {
 363             // Shouldn't happen
 364             return "Failure encoding error response: " + e;
 365         }
 366     }
 367
 368     private static void writeRootElement(final XMLStreamWriter xmlWriter, final NormalizedNodeWriter nnWriter,
 369                                          final ContainerNode data)
 370             throws IOException {
 371         try {
 372             final QName name = SchemaContext.NAME;
 373             xmlWriter.writeStartElement(name.getNamespace().toString(), name.getLocalName());
 374             for (final DataContainerChild<? extends PathArgument, ?> child : data.getValue()) {
 375                 nnWriter.write(child);
 376             }
 377             nnWriter.flush();
 378             xmlWriter.writeEndElement();
 379             xmlWriter.flush();
 380         } catch (final XMLStreamException e) {
 381             Throwables.propagate(e);
 382         }
 383     }
 384
 385     private static void writeDataRoot(final OutputStreamWriter outputWriter, final NormalizedNodeWriter nnWriter,
 386                                       final ContainerNode data) throws IOException {
 387         final Iterator<DataContainerChild<? extends PathArgument, ?>> iterator = data.getValue().iterator();
 388         while (iterator.hasNext()) {
 389             final DataContainerChild<? extends PathArgument, ?> child = iterator.next();
 390             nnWriter.write(child);
 391             nnWriter.flush();
 392         }
 393     }
 394 }