restconf/sal-rest-connector/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.netconf.sal.restconf.impl.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.JSONCodecFactory;
  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 String streamName;
  52     private final SchemaPath path;
  53     private final String outputType;
  54
  55     private SchemaContext schemaContext;
  56     private DOMNotification notification;
  57
  58     /**
  59      * Set path of listener and stream name, register event bus.
  60      *
  61      * @param path
  62      *             path of notification
  63      * @param streamName
  64      *             stream name of listener
  65      * @param outputType
  66      *             type of output on notification (JSON, XML)
  67      */
  68     NotificationListenerAdapter(final SchemaPath path, final String streamName, final String outputType) {
  69         super();
  70         register(this);
  71         setLocalNameOfPath(path.getLastComponent().getLocalName());
  72
  73         this.outputType = Preconditions.checkNotNull(outputType);
  74         this.path = Preconditions.checkNotNull(path);
  75         Preconditions.checkArgument(streamName != null && !streamName.isEmpty());
  76         this.streamName = streamName;
  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     public void onNotification(final DOMNotification notification) {
  91         this.schemaContext = ControllerContext.getInstance().getGlobalSchema();
  92         this.notification = notification;
  93
  94         final String xml = prepareXml();
  95         if (checkQueryParams(xml, this)) {
  96             prepareAndPostData(xml);
  97         }
  98     }
  99
 100     /**
 101      * Get stream name of this listener.
 102      *
 103      * @return {@link String}
 104      */
 105     @Override
 106     public String getStreamName() {
 107         return this.streamName;
 108     }
 109
 110     /**
 111      * Get schema path of notification.
 112      *
 113      * @return {@link SchemaPath}
 114      */
 115     public SchemaPath getSchemaPath() {
 116         return this.path;
 117     }
 118
 119     /**
 120      * Prepare data of notification and data to client.
 121      *
 122      * @param xml   data
 123      */
 124     private void prepareAndPostData(final String xml) {
 125         final Event event = new Event(EventType.NOTIFY);
 126         if (this.outputType.equals("JSON")) {
 127             event.setData(prepareJson());
 128         } else {
 129             event.setData(xml);
 130         }
 131         post(event);
 132     }
 133
 134     /**
 135      * Prepare json from notification data.
 136      *
 137      * @return json as {@link String}
 138      */
 139     @VisibleForTesting
 140     String prepareJson() {
 141         JsonParser jsonParser = new JsonParser();
 142         JsonObject json = new JsonObject();
 143         json.add("ietf-restconf:notification", jsonParser.parse(writeBodyToString()));
 144         json.addProperty("event-time", ListenerAdapter.toRFC3339(Instant.now()));
 145         return json.toString();
 146     }
 147
 148     @VisibleForTesting
 149     void setNotification(final DOMNotification notification) {
 150         this.notification = Preconditions.checkNotNull(notification);
 151     }
 152
 153     @VisibleForTesting
 154     void setSchemaContext(final SchemaContext schemaContext) {
 155         this.schemaContext = Preconditions.checkNotNull(schemaContext);
 156     }
 157
 158     private String writeBodyToString() {
 159         final Writer writer = new StringWriter();
 160         final NormalizedNodeStreamWriter jsonStream =
 161                 JSONNormalizedNodeStreamWriter.createExclusiveWriter(JSONCodecFactory.getShared(this.schemaContext),
 162                         this.notification.getType(), null, JsonWriterFactory.createJsonWriter(writer));
 163         final NormalizedNodeWriter nodeWriter = NormalizedNodeWriter.forStreamWriter(jsonStream);
 164         try {
 165             nodeWriter.write(this.notification.getBody());
 166             nodeWriter.close();
 167         } catch (final IOException e) {
 168             throw new RestconfDocumentedException("Problem while writing body of notification to JSON. ", e);
 169         }
 170         return writer.toString();
 171     }
 172
 173     private String prepareXml() {
 174         final Document doc = createDocument();
 175         final Element notificationElement = basePartDoc(doc);
 176
 177         final Element notificationEventElement = doc.createElementNS(
 178                 "urn:opendaylight:params:xml:ns:yang:controller:md:sal:remote", "create-notification-stream");
 179         addValuesToNotificationEventElement(doc, notificationEventElement, this.notification, this.schemaContext);
 180         notificationElement.appendChild(notificationEventElement);
 181
 182         return transformDoc(doc);
 183     }
 184
 185     private void addValuesToNotificationEventElement(final Document doc, final Element element,
 186             final DOMNotification notification, final SchemaContext schemaContext) {
 187         if (notification == null) {
 188             return;
 189         }
 190
 191         final NormalizedNode<NodeIdentifier, Collection<DataContainerChild<? extends PathArgument, ?>>> body =
 192                 notification.getBody();
 193         try {
 194
 195             final DOMResult domResult = writeNormalizedNode(body, schemaContext, this.path);
 196             final Node result = doc.importNode(domResult.getNode().getFirstChild(), true);
 197             final Element dataElement = doc.createElement("notification");
 198             dataElement.appendChild(result);
 199             element.appendChild(dataElement);
 200         } catch (final IOException e) {
 201             LOG.error("Error in writer ", e);
 202         } catch (final XMLStreamException e) {
 203             LOG.error("Error processing stream", e);
 204         }
 205     }
 206 }