public void initProcitys() {
 logger.info("获取所在地区");
 List<Provincials> provincials = Provincials.me.getProvincials();
 for (Provincials provincial : provincials) {
 List<Citys> citys = Citys.me.getCitysByProvincialId(provincial.getLong("id"));
 provincial.put("citys", JsonKit.toJson(citys));
 }
 setAttr("provincials", provincials);
 render("procity.jsp");
}

<select name="province_code" id="province_select">
 <c:forEach items="${provincials}" var="item">
 <option value="${item.procode}" cdata='${item.citys}'>${item.proname}</option>
 </c:forEach>
</select>
<select name="city_code" id="city_select">
</select>

$(function() {
 provincialChange();
 var $provincial = $("#province_select");
 $provincial.change(provincialChange);
});
function provincialChange() {
 var $provincial = $("#province_select");
 // 省级显示的code值
 var provincial_code = $provincial.val();
 var $selectedOption = $('#province_select option[value=' + provincial_code + ']');
 var city_data = YUNM.jsonEval($selectedOption.attr("cdata"));
 // 市级的菜单列表
 $city_select = $("#city_select");
 $city_select.empty();
 for (var i = 0; i < city_data.length;i++ ) {
 var code = city_data[i].code;
 var cname = city_data[i].cname;
 $city_select.append("<option value='"+code+"'>"+cname+"</option>");
 }
}