Java tutorial
/* * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.netconf.notifications.impl.ops; import com.google.common.base.Optional; import com.google.common.base.Preconditions; import com.google.common.collect.Lists; import java.util.Date; import java.util.List; import org.opendaylight.controller.config.util.xml.DocumentedException; import org.opendaylight.controller.config.util.xml.XmlElement; import org.opendaylight.controller.config.util.xml.XmlUtil; import org.opendaylight.netconf.api.NetconfSession; import org.opendaylight.netconf.api.xml.XmlNetconfConstants; import org.opendaylight.netconf.mapping.api.SessionAwareNetconfOperation; import org.opendaylight.netconf.notifications.NetconfNotification; import org.opendaylight.netconf.notifications.NetconfNotificationListener; import org.opendaylight.netconf.notifications.NetconfNotificationRegistry; import org.opendaylight.netconf.notifications.NotificationListenerRegistration; import org.opendaylight.netconf.notifications.impl.NetconfNotificationManager; import org.opendaylight.netconf.util.mapping.AbstractSingletonNetconfOperation; import org.opendaylight.netconf.util.messages.SubtreeFilter; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.CreateSubscriptionInput; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.netconf.notification._1._0.rev080714.StreamNameType; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; /** * Create subscription listens for create subscription requests and registers notification listeners into notification registry. * Received notifications are sent to the client right away */ public class CreateSubscription extends AbstractSingletonNetconfOperation implements SessionAwareNetconfOperation, AutoCloseable { private static final Logger LOG = LoggerFactory.getLogger(CreateSubscription.class); static final String CREATE_SUBSCRIPTION = "create-subscription"; private final NetconfNotificationRegistry notifications; private final List<NotificationListenerRegistration> subscriptions = Lists.newArrayList(); private NetconfSession netconfSession; public CreateSubscription(final String netconfSessionIdForReporting, final NetconfNotificationRegistry notifications) { super(netconfSessionIdForReporting); this.notifications = notifications; } @Override protected Element handleWithNoSubsequentOperations(final Document document, final XmlElement operationElement) throws DocumentedException { operationElement.checkName(CREATE_SUBSCRIPTION); operationElement.checkNamespace(CreateSubscriptionInput.QNAME.getNamespace().toString()); // FIXME reimplement using CODEC_REGISTRY and parse everything into generated class instance // Binding doesn't support anyxml nodes yet, so filter could not be retrieved // xml -> normalized node -> CreateSubscriptionInput conversion could be slower than current approach final Optional<XmlElement> filter = operationElement .getOnlyChildElementWithSameNamespaceOptionally("filter"); // Replay not supported final Optional<XmlElement> startTime = operationElement .getOnlyChildElementWithSameNamespaceOptionally("startTime"); Preconditions.checkArgument(startTime.isPresent() == false, "StartTime element not yet supported"); // Stop time not supported final Optional<XmlElement> stopTime = operationElement .getOnlyChildElementWithSameNamespaceOptionally("stopTime"); Preconditions.checkArgument(stopTime.isPresent() == false, "StopTime element not yet supported"); final StreamNameType streamNameType = parseStreamIfPresent(operationElement); Preconditions.checkNotNull(netconfSession); // Premature streams are allowed (meaning listener can register even if no provider is available yet) if (notifications.isStreamAvailable(streamNameType) == false) { LOG.warn("Registering premature stream {}. No publisher available yet for session {}", streamNameType, getNetconfSessionIdForReporting()); } final NotificationListenerRegistration notificationListenerRegistration = notifications .registerNotificationListener(streamNameType, new NotificationSubscription(netconfSession, filter)); subscriptions.add(notificationListenerRegistration); return XmlUtil.createElement(document, XmlNetconfConstants.OK, Optional.<String>absent()); } private static StreamNameType parseStreamIfPresent(final XmlElement operationElement) throws DocumentedException { final Optional<XmlElement> stream = operationElement .getOnlyChildElementWithSameNamespaceOptionally("stream"); return stream.isPresent() ? new StreamNameType(stream.get().getTextContent()) : NetconfNotificationManager.BASE_STREAM_NAME; } @Override protected String getOperationName() { return CREATE_SUBSCRIPTION; } @Override protected String getOperationNamespace() { return CreateSubscriptionInput.QNAME.getNamespace().toString(); } @Override public void setSession(final NetconfSession session) { this.netconfSession = session; } @Override public void close() { netconfSession = null; // Unregister from notification streams for (final NotificationListenerRegistration subscription : subscriptions) { subscription.close(); } } private static class NotificationSubscription implements NetconfNotificationListener { private final NetconfSession currentSession; private final Optional<XmlElement> filter; public NotificationSubscription(final NetconfSession currentSession, final Optional<XmlElement> filter) { this.currentSession = currentSession; this.filter = filter; } @Override public void onNotification(final StreamNameType stream, final NetconfNotification notification) { if (filter.isPresent()) { try { final Optional<Document> filtered = SubtreeFilter .applySubtreeNotificationFilter(this.filter.get(), notification.getDocument()); if (filtered.isPresent()) { final Date eventTime = notification.getEventTime(); currentSession.sendMessage(new NetconfNotification(filtered.get(), eventTime)); } } catch (DocumentedException e) { LOG.warn(e.toString()); currentSession.sendMessage(notification); } } else { currentSession.sendMessage(notification); } } } }