opendaylight/netconf/netconf-client/src/main/java/org/opendaylight/controller/netconf/client/NetconfClientSessionNegotiator.java

   1 /*
   2  * Copyright (c) 2013 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
   9 package org.opendaylight.controller.netconf.client;
  10
  11 import java.util.Collection;
  12 import java.util.List;
  13
  14 import javax.annotation.Nullable;
  15 import javax.xml.xpath.XPathConstants;
  16 import javax.xml.xpath.XPathExpression;
  17
  18 import org.opendaylight.controller.netconf.api.NetconfSessionPreferences;
  19 import org.opendaylight.controller.netconf.util.AbstractNetconfSessionNegotiator;
  20 import org.opendaylight.controller.netconf.util.messages.NetconfHelloMessage;
  21 import org.opendaylight.controller.netconf.util.xml.XMLNetconfUtil;
  22 import org.opendaylight.controller.netconf.util.xml.XmlElement;
  23 import org.opendaylight.controller.netconf.util.xml.XmlNetconfConstants;
  24 import org.opendaylight.controller.netconf.util.xml.XmlUtil;
  25 import org.w3c.dom.Document;
  26 import org.w3c.dom.Node;
  27
  28 import com.google.common.base.Function;
  29 import com.google.common.collect.Collections2;
  30
  31 import io.netty.channel.Channel;
  32 import io.netty.util.Timer;
  33 import io.netty.util.concurrent.Promise;
  34
  35 public class NetconfClientSessionNegotiator extends
  36         AbstractNetconfSessionNegotiator<NetconfSessionPreferences, NetconfClientSession, NetconfClientSessionListener> {
  37
  38     protected NetconfClientSessionNegotiator(NetconfSessionPreferences sessionPreferences,
  39             Promise<NetconfClientSession> promise, Channel channel, Timer timer, NetconfClientSessionListener sessionListener,
  40             long connectionTimeoutMillis) {
  41         super(sessionPreferences, promise, channel, timer, sessionListener, connectionTimeoutMillis);
  42     }
  43
  44     private static Collection<String> getCapabilities(Document doc) {
  45         XmlElement responseElement = XmlElement.fromDomDocument(doc);
  46         XmlElement capabilitiesElement = responseElement
  47                 .getOnlyChildElementWithSameNamespace(XmlNetconfConstants.CAPABILITIES);
  48         List<XmlElement> caps = capabilitiesElement.getChildElements(XmlNetconfConstants.CAPABILITY);
  49         return Collections2.transform(caps, new Function<XmlElement, String>() {
  50
  51             @Nullable
  52             @Override
  53             public String apply(@Nullable XmlElement input) {
  54                 // Trim possible leading/tailing whitespace
  55                 return input.getTextContent().trim();
  56             }
  57         });
  58     }
  59
  60     private static final XPathExpression sessionIdXPath = XMLNetconfUtil
  61             .compileXPath("/netconf:hello/netconf:session-id");
  62
  63     private long extractSessionId(Document doc) {
  64         final Node sessionIdNode = (Node) XmlUtil.evaluateXPath(sessionIdXPath, doc, XPathConstants.NODE);
  65         String textContent = sessionIdNode.getTextContent();
  66         if (textContent == null || textContent.equals("")) {
  67             throw new IllegalStateException("Session id not received from server");
  68         }
  69
  70         return Long.valueOf(textContent);
  71     }
  72
  73     @Override
  74     protected NetconfClientSession getSession(NetconfClientSessionListener sessionListener, Channel channel, NetconfHelloMessage message) {
  75         return new NetconfClientSession(sessionListener, channel, extractSessionId(message.getDocument()),
  76                 getCapabilities(message.getDocument()));
  77     }
  78 }