@RequestMappingpublic 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'>選擇區（可選）</option>";     $.each(msg, function(i) {       var $bean = msg[i];       vHtml += '<option value="' + $bean.pName + '"">'          + $bean.zName + '</option>';     });     region.html(vHtml);   } });