opendaylight/netconf/netconf-util/src/main/java/org/opendaylight/controller/netconf/util/messages/NetconfHelloMessage.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.util.messages;
  10
  11 import org.opendaylight.controller.netconf.api.NetconfMessage;
  12
  13 import java.util.Set;
  14
  15 import org.opendaylight.controller.netconf.api.NetconfDocumentedException;
  16 import org.opendaylight.controller.netconf.util.exception.MissingNameSpaceException;
  17 import org.opendaylight.controller.netconf.util.xml.XmlElement;
  18 import org.opendaylight.controller.netconf.util.xml.XmlNetconfConstants;
  19 import org.opendaylight.controller.netconf.util.xml.XmlUtil;
  20 import org.w3c.dom.Document;
  21 import org.w3c.dom.Element;
  22
  23 import com.google.common.base.Optional;
  24 import com.google.common.base.Preconditions;
  25 import com.google.common.collect.Sets;
  26
  27 /**
  28  * NetconfMessage that can carry additional header with session metadata. See {@link org.opendaylight.controller.netconf.util.messages.NetconfHelloMessageAdditionalHeader}
  29  */
  30 public final class NetconfHelloMessage extends NetconfMessage {
  31
  32     public static final String HELLO_TAG = "hello";
  33
  34     private final NetconfHelloMessageAdditionalHeader additionalHeader;
  35
  36     public NetconfHelloMessage(Document doc, NetconfHelloMessageAdditionalHeader additionalHeader) throws NetconfDocumentedException {
  37         super(doc);
  38         checkHelloMessage(doc);
  39         this.additionalHeader = additionalHeader;
  40     }
  41
  42     public NetconfHelloMessage(Document doc) throws NetconfDocumentedException {
  43         this(doc, null);
  44     }
  45
  46     public Optional<NetconfHelloMessageAdditionalHeader> getAdditionalHeader() {
  47         return additionalHeader== null ? Optional.<NetconfHelloMessageAdditionalHeader>absent() : Optional.of(additionalHeader);
  48     }
  49
  50     private static void checkHelloMessage(Document doc) {
  51         Preconditions.checkArgument(isHelloMessage(doc),
  52                 "Hello message invalid format, should contain %s tag from namespace %s, but is: %s", HELLO_TAG,
  53                 XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0, XmlUtil.toString(doc));
  54     }
  55
  56     public static NetconfHelloMessage createClientHello(Iterable<String> capabilities,
  57                                                         Optional<NetconfHelloMessageAdditionalHeader> additionalHeaderOptional) throws NetconfDocumentedException {
  58         Document doc = createHelloMessageDoc(capabilities);
  59         return additionalHeaderOptional.isPresent() ? new NetconfHelloMessage(doc, additionalHeaderOptional.get())
  60                 : new NetconfHelloMessage(doc);
  61     }
  62
  63     private static Document createHelloMessageDoc(Iterable<String> capabilities) {
  64         Document doc = XmlUtil.newDocument();
  65         Element helloElement = doc.createElementNS(XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0,
  66                 HELLO_TAG);
  67         Element capabilitiesElement = doc.createElement(XmlNetconfConstants.CAPABILITIES);
  68
  69         for (String capability : Sets.newHashSet(capabilities)) {
  70             Element capElement = doc.createElement(XmlNetconfConstants.CAPABILITY);
  71             capElement.setTextContent(capability);
  72             capabilitiesElement.appendChild(capElement);
  73         }
  74
  75         helloElement.appendChild(capabilitiesElement);
  76
  77         doc.appendChild(helloElement);
  78         return doc;
  79     }
  80
  81     public static NetconfHelloMessage createServerHello(Set<String> capabilities, long sessionId) throws NetconfDocumentedException {
  82         Document doc = createHelloMessageDoc(capabilities);
  83         Element sessionIdElement = doc.createElement(XmlNetconfConstants.SESSION_ID);
  84         sessionIdElement.setTextContent(Long.toString(sessionId));
  85         doc.getDocumentElement().appendChild(sessionIdElement);
  86         return new NetconfHelloMessage(doc);
  87     }
  88
  89     public static boolean isHelloMessage(final NetconfMessage msg) {
  90         Document document = msg.getDocument();
  91         return isHelloMessage(document);
  92     }
  93
  94     private static boolean isHelloMessage(final Document document) {
  95         XmlElement element = XmlElement.fromDomElement(document.getDocumentElement());
  96         try {
  97             return element.getName().equals(HELLO_TAG) &&
  98                    element.hasNamespace() &&
  99                    element.getNamespace().equals(XmlNetconfConstants.URN_IETF_PARAMS_XML_NS_NETCONF_BASE_1_0);
 100         } catch (MissingNameSpaceException e) {
 101             // Cannot happen, since we check for hasNamespace
 102             throw new IllegalStateException(e);
 103         }
 104     }
 105 }