if (message == null && client.getListener().getUndeliveredMessages().size() == 0) {
                Continuation continuation = ContinuationSupport.getContinuation(request);

                // Add a listener to the continuation to make sure it actually
                // will expire (seems like a bug in Jetty Servlet 3 continuations,
                // see https://issues.apache.org/jira/browse/AMQ-3447
                continuation.addContinuationListener(new ContinuationListener() {
                    @Override
                    public void onTimeout(Continuation cont) {
                        if (LOG.isDebugEnabled()) {
                            LOG.debug("Continuation " + cont.toString() + " expired.");
                        }
                    }

                    @Override
                    public void onComplete(Continuation cont) {
                        if (LOG.isDebugEnabled()) {
                           LOG.debug("Continuation " + cont.toString() + " completed.");
                        }
                    }
                });

                if (continuation.isExpired()) {
                    response.setStatus(HttpServletResponse.SC_OK);
                    StringWriter swriter = new StringWriter();
                    PrintWriter writer = new PrintWriter(swriter);
                    writer.println("<ajax-response>");
                    writer.print("</ajax-response>");

                    writer.flush();
                    String m = swriter.toString();
                    response.getWriter().println(m);

                    return;
                }

                continuation.setTimeout(timeout);
                continuation.suspend();
                LOG.debug( "Suspending continuation " + continuation );

                // Fetch the listeners
                AjaxListener listener = client.getListener();
                listener.access();

                // register this continuation with our listener.
                listener.setContinuation(continuation);

                return;
            }