用struts,jquery-easyui省市级联小例子
1。运用的是jquery-easyui中combobox组件，前端展示引入jquery-1.7.1.min.js和
jquery.easyui.min.js包,直接看代码:
(1)前端html代码如下：

public class CityAction  extends DispatchAction{         /**          取得所有省份          */public ActionForward queryProvince(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response)throws Exception {List<City> list = null;CityDAO citydao = new CityDAO();list = citydao.findProvince();JSONArray json=JSONArray.fromObject(list);response.setContentType("text/json; charset=utf-8"); PrintWriter out=response.getWriter();  out.print(json);out.flush();return null;}/**         取得相应省份的市.         */public ActionForward queryCityByProvinceId(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response)throws Exception {String parentid = request.getParameter("parentid");List<City> list = null;CityDAO citydao = new CityDAO();if(parentid!=null&&!parentid.equals("null")){list = citydao.findCity(Long.parseLong(parentid));}JSONArray json=JSONArray.fromObject(list);response.setContentType("text/json; charset=utf-8"); PrintWriter out=response.getWriter();  out.print(json);out.flush();return null;}}