JSF 1.2到2.0 Ajax迁移

Question

We are migrating from Jsf 1.2 to 2.0 and having validation issues with drop down values updated through ajax using servlets.

What happens today is when a drop-down A is changed dropw-down B's values are fetched through ajax call using a servlet and in Jquery the drop-down values of B is changed based on the Ajax result but after migrating to JSF 2.0 we are getting invalid values issue for drop-down B when submitting the form because the updated drop-down values are not known to faces so wondering why it worked in JSF 1.1 but not 2.0. The bean is requestscoped

I know there is f:ajax with 2.0 but due to time constraint we are going to keep the servlets to make the ajax call if possible.

JSP

  <t:datalist value ='#{bean.locations}' var='loc'>
    <h:selectOneMenu id="country" value="#{loc.country}" onchange ='getStateListThroughServletAjax(this)'>
      <f:selectItems value ='#{loc.countryList}'/>
    </h:selectOneMenu> 
    <h:selectOneMenu id='states' value ='#{loc.state}'>
     <f:selectItems value='#{loc.stateList}'/>
    </h:selectOneMenu>  
  </t:datalist> 

Javascript

function getStateListThroughServletAjax(country){
   //this get the Statelist based on country selected by hitting the servlet
   var params = 'countryId='+ country.value;
  $.ajax({type: "POST", url: '\loadStates',data: params,
     success: function(response) {
       jsonResult = jQuery.parseJSON(response);
       //setComboOptions for state dropwdown based on JsonResult
        setComboOptionsForState(jsonResult)
     }
    });
 }

Anytime i change the country i get a new statelist populated but while saving i get "Validation Error: Value is not valid ".

Any input is appreciated