/**
   * Set our own caps version.
   *
   * @param discoverInfo the {@link DiscoverInfo} that we'd like to map to the <tt>capsVersion</tt>.
   * @param capsVersion the new caps version
   */
  public void setCurrentCapsVersion(DiscoverInfo discoverInfo, String capsVersion) {
    Caps caps = new Caps(getNode(), CapsPacketExtension.HASH_METHOD, capsVersion, null);

    /*
     * DiscoverInfo carries the node and the ver and we're now setting a new
     * ver so we should update the DiscoveryInfo.
     */
    discoverInfo.setNode(caps.getNodeVer());

    if (!caps.isValid(discoverInfo)) {
      throw new IllegalArgumentException(
          "The specified discoverInfo must be valid with respect"
              + " to the specified capsVersion");
    }

    currentCapsVersion = capsVersion;
    addDiscoverInfoByCaps(caps, discoverInfo);
    fireCapsVerChanged();
  }
  /**
   * Retrieve DiscoverInfo for a specific node.
   *
   * @param caps the <tt>Caps</tt> i.e. the node, the hash and the ver
   * @return The corresponding DiscoverInfo or null if none is known.
   */
  public static DiscoverInfo getDiscoverInfoByCaps(Caps caps) {
    synchronized (caps2discoverInfo) {
      DiscoverInfo discoverInfo = caps2discoverInfo.get(caps);

      /*
       * If we don't have the discoverInfo in the runtime cache yet, we
       * may have it remembered in a previous application instance.
       */
      if (discoverInfo == null) {
        ConfigurationService configurationService = getConfigService();
        String capsPropertyName = getCapsPropertyName(caps);
        String xml = configurationService.getString(capsPropertyName);

        if ((xml != null) && (xml.length() != 0)) {
          IQProvider discoverInfoProvider =
              (IQProvider)
                  ProviderManager.getInstance()
                      .getIQProvider("query", "http://jabber.org/protocol/disco#info");

          if (discoverInfoProvider != null) {
            XmlPullParser parser = new MXParser();

            try {
              parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, true);
              parser.setInput(new StringReader(xml));
              // Start the parser.
              parser.next();
            } catch (XmlPullParserException xppex) {
              parser = null;
            } catch (IOException ioex) {
              parser = null;
            }

            if (parser != null) {
              try {
                discoverInfo = (DiscoverInfo) discoverInfoProvider.parseIQ(parser);
              } catch (Exception ex) {
              }

              if (discoverInfo != null) {
                if (caps.isValid(discoverInfo)) caps2discoverInfo.put(caps, discoverInfo);
                else {
                  logger.error(
                      "Invalid DiscoverInfo for " + caps.getNodeVer() + ": " + discoverInfo);
                  /*
                   * The discoverInfo doesn't seem valid
                   * according to the caps which means that we
                   * must have stored invalid information.
                   * Delete the invalid information in order
                   * to not try to validate it again.
                   */
                  configurationService.removeProperty(capsPropertyName);
                }
              }
            }
          }
        }
      }
      return discoverInfo;
    }
  }