@Override
protected void doPost(HttpServletRequest servletRequest, HttpServletResponse servletResponse)
        throws IOException {
    VoiceResponse response = new VoiceResponse.Builder()
            .gather(new Gather.Builder()
                    .action("/menu/show")
                    .numDigits(1)
                    .build())
            .say(new Say.Builder("Привет")
                  .voice(Say.Voice.ALICE)
                  .language(Say.Language.RU_RU)
                  .build())
            .build();

    servletResponse.setContentType("text/xml");
    try {
        servletResponse.getWriter().write(response.toXml());
    } catch (TwiMLException e) {
        throw new RuntimeException(e);
    }
}