Another version of extractTitle for TitleHelper - not tested.

TitleHelper

  public static String getTitle(WaveId waveId, WaveletId waveletId, WaveMap waveMap,
      ConversationUtil conversationUtil) {
    String title = "";
    WaveViewData wave =
        AbstractSearchProviderImpl.buildWaveViewData(waveId, Lists.newArrayList(waveletId),
            SolrSearchProviderImpl.matchesFunction, waveMap);


    OpBasedWavelet wavelet = OpBasedWavelet.createReadOnly(wave.getWavelet(waveletId));
    if (WaveletBasedConversation.waveletHasConversation(wavelet)) {
      ObservableConversationView conversations = conversationUtil.buildConversation(wavelet);

      ObservableConversation rootConversation = conversations.getRoot();
      ObservableConversationBlip firstBlip = null;
      if (rootConversation != null && rootConversation.getRootThread() != null
          && rootConversation.getRootThread().getFirstBlip() != null) {
        firstBlip = rootConversation.getRootThread().getFirstBlip();
      }
      if (firstBlip != null) {
        Document firstBlipContents = firstBlip.getContent();
        title = TitleHelper.extractTitle(firstBlipContents).trim();
      }
    }
    return title;
  }