restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/streams/listeners/NotificationListenerAdapter.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.netconf.sal.streams.listeners;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import com.google.common.base.Preconditions;
  12 import com.google.gson.JsonObject;
  13 import com.google.gson.JsonParser;
  14 import java.io.IOException;
  15 import java.io.StringWriter;
  16 import java.io.Writer;
  17 import java.time.Instant;
  18 import java.util.Collection;
  19 import javax.xml.stream.XMLStreamException;
  20 import javax.xml.transform.dom.DOMResult;
  21 import org.opendaylight.controller.md.sal.dom.api.DOMNotification;
  22 import org.opendaylight.controller.md.sal.dom.api.DOMNotificationListener;
  23 import org.opendaylight.netconf.sal.restconf.impl.ControllerContext;
  24 import org.opendaylight.restconf.common.errors.RestconfDocumentedException;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  27 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  28 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  29 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  30 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  31 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  32 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  33 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  34 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  35 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38 import org.w3c.dom.Document;
  39 import org.w3c.dom.Element;
  40 import org.w3c.dom.Node;
  41
  42 /**
  43  * {@link NotificationListenerAdapter} is responsible to track events on
  44  * notifications.
  45  *
  46  */
  47 public class NotificationListenerAdapter extends AbstractCommonSubscriber implements DOMNotificationListener {
  48
  49     private static final Logger LOG = LoggerFactory.getLogger(NotificationListenerAdapter.class);
  50
  51     private final ControllerContext controllerContext;
  52     private final String streamName;
  53     private final SchemaPath path;
  54     private final String outputType;
  55
  56     private SchemaContext schemaContext;
  57     private DOMNotification notification;
  58
  59     /**
  60      * Set path of listener and stream name, register event bus.
  61      *
  62      * @param path
  63      *             path of notification
  64      * @param streamName
  65      *             stream name of listener
  66      * @param outputType
  67      *             type of output on notification (JSON, XML)
  68      */
  69     NotificationListenerAdapter(final SchemaPath path, final String streamName, final String outputType,
  70             final ControllerContext controllerContext) {
  71         register(this);
  72         this.outputType = Preconditions.checkNotNull(outputType);
  73         this.path = Preconditions.checkNotNull(path);
  74         Preconditions.checkArgument(streamName != null && !streamName.isEmpty());
  75         this.streamName = streamName;
  76         this.controllerContext = controllerContext;
  77     }
  78
  79     /**
  80      * Get outputType of listener.
  81      *
  82      * @return the outputType
  83      */
  84     @Override
  85     public String getOutputType() {
  86         return this.outputType;
  87     }
  88
  89     @Override
  90     @SuppressWarnings("checkstyle:hiddenField")
  91     public void onNotification(final DOMNotification notification) {
  92         this.schemaContext = controllerContext.getGlobalSchema();
  93         this.notification = notification;
  94
  95         final String xml = prepareXml();
  96         if (checkQueryParams(xml, this)) {
  97             prepareAndPostData(xml);
  98         }
  99     }
 100
 101     /**
 102      * Get stream name of this listener.
 103      *
 104      * @return {@link String}
 105      */
 106     @Override
 107     public String getStreamName() {
 108         return this.streamName;
 109     }
 110
 111     /**
 112      * Get schema path of notification.
 113      *
 114      * @return {@link SchemaPath}
 115      */
 116     public SchemaPath getSchemaPath() {
 117         return this.path;
 118     }
 119
 120     /**
 121      * Prepare data of notification and data to client.
 122      *
 123      * @param xml   data
 124      */
 125     private void prepareAndPostData(final String xml) {
 126         final Event event = new Event(EventType.NOTIFY);
 127         if (this.outputType.equals("JSON")) {
 128             event.setData(prepareJson());
 129         } else {
 130             event.setData(xml);
 131         }
 132         post(event);
 133     }
 134
 135     /**
 136      * Prepare json from notification data.
 137      *
 138      * @return json as {@link String}
 139      */
 140     @VisibleForTesting
 141     String prepareJson() {
 142         final JsonParser jsonParser = new JsonParser();
 143         final JsonObject json = new JsonObject();
 144         json.add("ietf-restconf:notification", jsonParser.parse(writeBodyToString()));
 145         json.addProperty("event-time", ListenerAdapter.toRFC3339(Instant.now()));
 146         return json.toString();
 147     }
 148
 149     @VisibleForTesting
 150     void setNotification(final DOMNotification notification) {
 151         this.notification = Preconditions.checkNotNull(notification);
 152     }
 153
 154     @VisibleForTesting
 155     void setSchemaContext(final SchemaContext schemaContext) {
 156         this.schemaContext = Preconditions.checkNotNull(schemaContext);
 157     }
 158
 159     private String writeBodyToString() {
 160         final Writer writer = new StringWriter();
 161         final NormalizedNodeStreamWriter jsonStream = JSONNormalizedNodeStreamWriter.createExclusiveWriter(
 162             JSONCodecFactorySupplier.DRAFT_LHOTKA_NETMOD_YANG_JSON_02.getShared(this.schemaContext),
 163             this.notification.getType(), null, JsonWriterFactory.createJsonWriter(writer));
 164         final NormalizedNodeWriter nodeWriter = NormalizedNodeWriter.forStreamWriter(jsonStream);
 165         try {
 166             nodeWriter.write(this.notification.getBody());
 167             nodeWriter.close();
 168         } catch (final IOException e) {
 169             throw new RestconfDocumentedException("Problem while writing body of notification to JSON. ", e);
 170         }
 171         return writer.toString();
 172     }
 173
 174     private String prepareXml() {
 175         final Document doc = createDocument();
 176         final Element notificationElement = basePartDoc(doc);
 177
 178         final Element notificationEventElement = doc.createElementNS(
 179                 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "create-notification-stream");
 180         addValuesToNotificationEventElement(doc, notificationEventElement);
 181         notificationElement.appendChild(notificationEventElement);
 182
 183         return transformDoc(doc);
 184     }
 185
 186     private void addValuesToNotificationEventElement(final Document doc, final Element element) {
 187         final NormalizedNode<NodeIdentifier, Collection<DataContainerChild<? extends PathArgument, ?>>> body =
 188                 notification.getBody();
 189         try {
 190
 191             final DOMResult domResult = writeNormalizedNode(body, schemaContext, this.path);
 192             final Node result = doc.importNode(domResult.getNode().getFirstChild(), true);
 193             final Element dataElement = doc.createElement("notification");
 194             dataElement.appendChild(result);
 195             element.appendChild(dataElement);
 196         } catch (final IOException e) {
 197             LOG.error("Error in writer ", e);
 198         } catch (final XMLStreamException e) {
 199             LOG.error("Error processing stream", e);
 200         }
 201     }
 202 }