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