java - Struts2: repopulating textboxes with List<Integer> after validation -

i have jsp page has code this::

 <div id="textboxesgroup">                                      <div class="control-group"> <label class="control-label" for="inputauto">room type</label> <div class="controls"> <!-- <input type="text" id="inputauto" class="grd-white" /> --> <s:select id="inputauto" data-form="select2" cssstyle="width:200px" data-placeholder="select room type" name="resortroomtype" headerkey="-1" list="roomtypelist"/> </div>  </div>  <div class="control-group"> <label class="control-label" for="inputauto">room numbers</label> <div class="controls"> <!-- <input type="text" id="inputauto" class="grd-white" /> --> <s:textfield id="inputauto" cssclass="grd-white" name="roomnumbers" onkeypress="return isnumber(event)"/> <s:label name="roomnumbererror" cssclass="help-inline" cssstyle=" color: red;"></s:label> </div>   </div>  </div>  <div >   <input type='button' value='+' id='addbutton' class="btn " />                                                       <input type='button' value='-' id='removebutton' class="btn" /> </div> 

my js add , remove button is::

 <script type="text/javascript">        $(document).ready(function () {          $("#addbutton").click(function () {            if( ($('#textboxesgroup').children().size()+1) > 12) {              alert("resort don't have more rooms" );                return false;                  }            var id = ($('#textboxesgroup').children().size()+1).tostring();             $('#textboxesgroup').append('<div class="control-group" id="control-group">  <label class="control-label" for="inputselectgroup">room type</label>   <div class="controls"><select style="width:200px" id="inputselectgroup" name="resortroomtype" data-form="select2">      <option value="single room">single room</option>     <option value="double room">double room</option>     <option value="twin room">twin room</option>     <option value="interconnecting room">interconnecting room</option>     <option value="suite">suite</option>     <option value="pent house suite">pent house suite</option>      </select>     </div>     </div>      <div class="control-group" id="control-group">      <label class="control-label" for="inputauto">number of rooms</label>      <div class="controls">      <input type="text" class="grd-white" id="inputauto" name="roomnumbers"      onkeypress="return  isnumber(event)" >       </div>     </div>');           });              $("#removebutton").click(function () {                if ($('#textboxesgroup').children().size() == 2) {                   alert("no more textbox remove");                     return false;                      }                  $('#textboxesgroup').children().last().remove();                 $('#textboxesgroup').children().last().remove();                     });                 });   </script> 

and in action class i've ::

private list<integer> roomnumbers; getter/setters; 

and i've validate method validate there field empty or not. if empty return input , i'll form page (e.g. add_resort.jsp). ex have input roomtype :: single room roomnumber ::2 , roomtype :: doubleroom roomnumber is:: empty (i forgot enter number) , click button save changes , validation happenes.. when return page in roomnumber text field got value this:::[2,null]

test case::::::

before validation roomnumber =2

after validation roomnumber=[2]

test case::::::

before validation roomnumber =2 roomnumber= null

after validation roomnumber=[2,null]

in validate method

if(roomnumbers != null){ roomnumbers.add(new integer(55)); setroomnumbers(roomnumbers); addfielderror("roomnumbers", "please enter valid room number."); }