@RequestMapping
public void getLocations(@RequestParam String location, PrintWriter printWriter) { 
  if (StringUtils.isEmpty(location)) { 
    return; 
  } 
  List<Location> locations = locationService.getSubLocation(location); 
  String json = Json.toJson(locations); 
  printWriter.write(json); 
  printWriter.flush(); 
  printWriter.close(); 
} 

$.ajax({ 
  type : "GET", 
  url : "/admin/location/getLocations.do", 
  data : "location=" + val, 
  success : function(msg) { 
    msg = eval(msg); 
    region = $("#region"); 
    region.empty(); 
    vHtml = "<option value='none'>选择区（可选）</option>"; 
    $.each(msg, function(i) { 
      var $bean = msg[i]; 
      vHtml += '<option value="' + $bean.pName + '"">'
          + $bean.zName + '</option>'; 
    }); 
    region.html(vHtml); 
  } 
});