restconf/restconf-nb-rfc8040/src/main/java/org/opendaylight/restconf/nb/rfc8040/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.restconf.nb.rfc8040.streams.listeners;
   9
  10 import static com.google.common.base.Preconditions.checkArgument;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import com.google.common.annotations.VisibleForTesting;
  14 import com.google.common.base.MoreObjects;
  15 import java.time.Instant;
  16 import java.util.Optional;
  17 import javax.xml.xpath.XPathExpressionException;
  18 import org.eclipse.jdt.annotation.Nullable;
  19 import org.opendaylight.mdsal.dom.api.DOMNotification;
  20 import org.opendaylight.mdsal.dom.api.DOMNotificationListener;
  21 import org.opendaylight.mdsal.dom.api.DOMNotificationService;
  22 import org.opendaylight.restconf.common.formatters.JSONNotificationFormatter;
  23 import org.opendaylight.restconf.common.formatters.NotificationFormatter;
  24 import org.opendaylight.restconf.common.formatters.NotificationFormatterFactory;
  25 import org.opendaylight.restconf.common.formatters.XMLNotificationFormatter;
  26 import org.opendaylight.yang.gen.v1.urn.sal.restconf.event.subscription.rev140708.NotificationOutputTypeGrouping.NotificationOutputType;
  27 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  28 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
  29 import org.slf4j.Logger;
  30 import org.slf4j.LoggerFactory;
  31
  32 /**
  33  * {@link NotificationListenerAdapter} is responsible to track events on notifications.
  34  */
  35 public class NotificationListenerAdapter extends AbstractCommonSubscriber implements DOMNotificationListener {
  36
  37     private static final Logger LOG = LoggerFactory.getLogger(NotificationListenerAdapter.class);
  38     private static final NotificationFormatterFactory JSON_FORMATTER_FACTORY = JSONNotificationFormatter.createFactory(
  39             JSONCodecFactorySupplier.RFC7951);
  40
  41     private final String streamName;
  42     private final Absolute path;
  43     private final NotificationOutputType outputType;
  44
  45     @VisibleForTesting NotificationFormatter formatter;
  46
  47
  48     /**
  49      * Set path of listener and stream name.
  50      *
  51      * @param path       Schema path of YANG notification.
  52      * @param streamName Name of the stream.
  53      * @param outputType Type of output on notification (JSON or XML).
  54      */
  55     NotificationListenerAdapter(final Absolute path, final String streamName, final String outputType) {
  56         setLocalNameOfPath(path.lastNodeIdentifier().getLocalName());
  57
  58         this.outputType = NotificationOutputType.forName(requireNonNull(outputType)).get();
  59         this.path = requireNonNull(path);
  60         this.streamName = requireNonNull(streamName);
  61         checkArgument(!streamName.isEmpty());
  62         formatter = getFormatterFactory().getFormatter();
  63
  64         LOG.debug("output type: {}, {}", outputType, this.outputType);
  65     }
  66
  67     private NotificationFormatterFactory getFormatterFactory() {
  68         switch (outputType) {
  69             case JSON:
  70                 return JSON_FORMATTER_FACTORY;
  71             case XML:
  72                 return XMLNotificationFormatter.FACTORY;
  73             default:
  74                 throw new IllegalArgumentException("Unsupported outputType " + outputType);
  75         }
  76     }
  77
  78     @Override
  79     final void setFilter(final @Nullable String filter) throws XPathExpressionException {
  80         final NotificationFormatterFactory factory = getFormatterFactory();
  81         formatter = filter == null || filter.isEmpty() ? factory.getFormatter() : factory.getFormatter(filter);
  82     }
  83
  84     /**
  85      * Get output type of this listener.
  86      *
  87      * @return The configured output type (JSON or XML).
  88      */
  89     @Override
  90     public String getOutputType() {
  91         return outputType.getName();
  92     }
  93
  94     @Override
  95     @SuppressWarnings("checkstyle:IllegalCatch")
  96     public void onNotification(final DOMNotification notification) {
  97         final Instant now = Instant.now();
  98         if (!checkStartStop(now, this)) {
  99             return;
 100         }
 101
 102         final Optional<String> maybeOutput;
 103         try {
 104             maybeOutput = formatter.eventData(schemaHandler.get(), notification, now, getLeafNodesOnly(),
 105                     isSkipNotificationData());
 106         } catch (Exception e) {
 107             LOG.error("Failed to process notification {}", notification, e);
 108             return;
 109         }
 110         if (maybeOutput.isPresent()) {
 111             post(maybeOutput.get());
 112         }
 113     }
 114
 115     /**
 116      * Get stream name of this listener.
 117      *
 118      * @return The configured stream name.
 119      */
 120     @Override
 121     public String getStreamName() {
 122         return streamName;
 123     }
 124
 125     /**
 126      * Get schema path of notification.
 127      *
 128      * @return The configured schema path that points to observing YANG notification schema node.
 129      */
 130     public Absolute getSchemaPath() {
 131         return path;
 132     }
 133
 134     public final synchronized void listen(final DOMNotificationService notificationService) {
 135         if (!isListening()) {
 136             setRegistration(notificationService.registerNotificationListener(this, getSchemaPath()));
 137         }
 138     }
 139
 140     @Override
 141     public String toString() {
 142         return MoreObjects.toStringHelper(this)
 143                 .add("path", path)
 144                 .add("stream-name", streamName)
 145                 .add("output-type", outputType)
 146                 .toString();
 147     }
 148 }