public void sendBye(String localSipURL, String remoteSipURL, ChatSession chatSession) {
    // Send a Bye only if there were exchanged messages!!!
    if (chatSession.isEstablishedSession()) {
      try {
        logger.debug("Sending a BYE in progress to " + remoteSipURL);

        SipProvider sipProvider = imUA.getSipProvider();

        javax.sip.Dialog dialog = chatSession.getDialog();

        Request request = dialog.createRequest(Request.BYE);

        // ProxyAuthorization header if not null:
        ProxyAuthorizationHeader proxyAuthHeader = imUA.getProxyAuthorizationHeader();
        if (proxyAuthHeader != null) request.setHeader(proxyAuthHeader);

        ClientTransaction clientTransaction = sipProvider.getNewClientTransaction(request);

        dialog.sendRequest(clientTransaction);
        logger.debug("BYE sent:\n" + request);

      } catch (Exception ex) {
        ex.printStackTrace();
      }
    } else {
      logger.debug("BYE not sent because of no exchanged messages!!!");
    }
  }
  public void sendSubscribe(String localURL, String buddyURI, boolean EXPIRED) {
    try {
      logger.debug("Sending SUBSCRIBE in progress to the buddy: " + buddyURI);
      int proxyPort = imUA.getProxyPort();
      String proxyAddress = imUA.getProxyAddress();
      String imProtocol = imUA.getIMProtocol();
      SipStack sipStack = imUA.getSipStack();
      SipProvider sipProvider = imUA.getSipProvider();
      MessageFactory messageFactory = imUA.getMessageFactory();
      HeaderFactory headerFactory = imUA.getHeaderFactory();
      AddressFactory addressFactory = imUA.getAddressFactory();

      // Request-URI:
      // URI requestURI=addressFactory.createURI(buddyURI);
      SipURI requestURI = addressFactory.createSipURI(null, proxyAddress);
      requestURI.setPort(proxyPort);
      requestURI.setTransportParam(imProtocol);

      // Call-Id:
      CallIdHeader callIdHeader = null;

      // CSeq:
      CSeqHeader cseqHeader = null;

      // To header:
      ToHeader toHeader = null;

      // From Header:
      FromHeader fromHeader = null;

      // Via header
      String branchId = Utils.generateBranchId();
      ViaHeader viaHeader =
          headerFactory.createViaHeader(
              imUA.getIMAddress(), imUA.getIMPort(), imProtocol, branchId);
      Vector viaList = new Vector();
      viaList.addElement(viaHeader);

      PresenceManager presenceManager = imUA.getPresenceManager();
      Presentity presentity = presenceManager.getPresentity(buddyURI);
      Dialog dialog = null;
      if (presentity != null) dialog = presentity.getDialog();

      if (dialog != null) {

        // We have to remove the subscriber and the Presentity related
        // with this Buddy...
        presenceManager.removePresentity(buddyURI);
        Subscriber subscriber = presenceManager.getSubscriber(buddyURI);
        if (subscriber == null) {
          // It means that the guy does not have us in his buddy list
          // nothing to do!!!
        } else {
          presenceManager.removeSubscriber(buddyURI);
        }

        Address localAddress = dialog.getLocalParty();
        Address remoteAddress = dialog.getRemoteParty();

        fromHeader = headerFactory.createFromHeader(localAddress, dialog.getLocalTag());
        toHeader = headerFactory.createToHeader(remoteAddress, dialog.getRemoteTag());

        long cseq = dialog.getLocalSeqNumber();
        cseqHeader = headerFactory.createCSeqHeader(cseq, "MESSAGE");

        callIdHeader = dialog.getCallId();
      } else {
        String localTag = Utils.generateTag();

        Address toAddress = addressFactory.createAddress(buddyURI);
        Address fromAddress = addressFactory.createAddress(localURL);

        fromHeader = headerFactory.createFromHeader(fromAddress, localTag);
        toHeader = headerFactory.createToHeader(toAddress, null);

        // CSeq:
        cseqHeader = headerFactory.createCSeqHeader(1L, "SUBSCRIBE");

        callIdCounter++;
        // Call-ID:
        callIdHeader =
            (CallIdHeader)
                headerFactory.createCallIdHeader("nist-sip-im-subscribe-callId" + callIdCounter);
      }

      // MaxForwards header:
      MaxForwardsHeader maxForwardsHeader = headerFactory.createMaxForwardsHeader(70);

      Request request =
          messageFactory.createRequest(
              requestURI,
              "SUBSCRIBE",
              callIdHeader,
              cseqHeader,
              fromHeader,
              toHeader,
              viaList,
              maxForwardsHeader);

      RouteHeader rh = this.imUA.getRouteToProxy();
      request.setHeader(rh);

      // Contact header:
      SipURI sipURI = addressFactory.createSipURI(null, imUA.getIMAddress());
      sipURI.setPort(imUA.getIMPort());
      sipURI.setTransportParam(imUA.getIMProtocol());
      Address contactAddress = addressFactory.createAddress(sipURI);
      ContactHeader contactHeader = headerFactory.createContactHeader(contactAddress);
      request.setHeader(contactHeader);

      ExpiresHeader expiresHeader = null;
      if (EXPIRED) {
        expiresHeader = headerFactory.createExpiresHeader(0);
      } else {
        expiresHeader = headerFactory.createExpiresHeader(presenceManager.getExpiresTime());
      }
      request.setHeader(expiresHeader);

      // WE have to add a new Header: "Event"
      Header eventHeader = headerFactory.createHeader("Event", "presence");
      request.setHeader(eventHeader);

      // Add Acceptw Header
      Header acceptHeader = headerFactory.createHeader("Accept", "application/pidf+xml");
      request.setHeader(acceptHeader);

      // ProxyAuthorization header if not null:
      ProxyAuthorizationHeader proxyAuthHeader = imUA.getProxyAuthorizationHeader();
      if (proxyAuthHeader != null) request.setHeader(proxyAuthHeader);

      ClientTransaction clientTransaction = sipProvider.getNewClientTransaction(request);

      if (dialog != null) {
        dialog.sendRequest(clientTransaction);
      } else {
        clientTransaction.sendRequest();
      }

      logger.debug("IMSubscribeProcessing, sendSubscribe(), SUBSCRIBE sent:\n" + request);
    } catch (Exception ex) {
      ex.printStackTrace();
    }
  }