<div class="form-group">
   <label class="control-label col-sm-2" >FMA:</label>
     <div class="col-sm-4">
        <input required type="text" id="txtFMA" name="txtFMA" pattern="[0-9]{9}" maxlength="9" minlength="9"class="form-control"
        placeholder="FMA"
       value="">
  </div>
  <section id="DatoFMA">
 </section>
</div>

function validar(){
       $('#txtFMA').keyup(function(){
    var _this = $('#txtFMA');
    var _user = $('#txtFMA').val();
                  if(_user.length == 9){
                         var res = $.ajax({
                             url: 'traslado',
                             dataType: 'json',
                             data: { miPostVar: _user },
                             type: 'post'
                         }).responseText;
                         document.getElementById("DatoFMA").innnerHTML = res;
                     }
    });

        }
            setInterval(validar,1000);

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    response.setContentType("text/html;charset=UTF-8");

    try (PrintWriter out = response.getWriter())
    {
        FeedlotTraslado td = new FeedlotTraslado();
        this.vfma = request.getParameter("miPostVar");
        try
        {
            if(!td.ExisteFMA(Integer.parseInt(this.vfma))){

                response(response, "error");
            }
        }catch (Exception ex) {
              Logger.getLogger(trasladoDestete.class.getName()).log(Level.SEVERE, null, ex);
        }
}
}

 private void response(HttpServletResponse resp, String msg)
        throws IOException {
    PrintWriter out = resp.getWriter();
       out.println("<h1>" + msg + "</h1>");
}
  @Override
  protected void doPost(HttpServletRequest request, HttpServletResponse response)
         throws ServletException, IOException {
        processRequest(request, response);
  }