最簡單下拉框二級聯動

 <script type="text/javascript">
    
      function loadCity(province) {
    $.ajax({
        type: "POST",
        url: "aa_getCity.do?dateparam=" + new Date(),
        data: {"province":province},
        dataType:"json",
        async : false,
        success: function(json){
         $("#city").empty();
         $("#city").append("<option value=''></option>");
            for(var i = 0; i < json.length; i++){
             if(json[i] != null) {
             $("#city").append("<option value="+json[i]["cityid"]+">"+json[i]["cityname"]+"</option>");
             }
            }
        },
        error:function (XMLHttpRequest, textStatus, errorThrown) {
      alert("加載城市異常：" + errorThrown);
        }
    });
   }
   
     </script>
    
    
<td class="class1"  width="20%">省份:</td>
<td class="class2"  width="30%">           
   <select name="province" id="province"  οnchange="loadCity(this.value);">
    <option value=""></option>
    <option value="00">北京</option>
    <option value="01">廣東</option>
</select>
</td>
<td class="class1"  width="20%">城市:</td>
  <td class="class2" width="30%">
  <select  name="city" id="city" ></select>
/td>

 

java:

 

public void doGetCity()
 {

  try {
   String province = getRequest().getParameter("province");
    List<Map<String,String>> resultCityList = new ArrayList<Map<String,String>>();
   
    List cityList = new CityList();//根據省份從數據庫或者其他地方取值
   
     for(CityListObj obj : cityList){
     Map<String,String> tmpMap = new HashMap<String,String>();
     tmpMap.put("DICTID", obj.getCityId());
     tmpMap.put("DICTNAME", obj.getCityName());
     
     resultCityList.add(tmpMap);
     } 
   }
  
     JSONArray jsonArray = JSONArray.fromObject(resultCityList);
     PrintWriter out = getResponse().getWriter();
     out.print(jsonArray.toString());
     out.close();
  }
   catch (Exception e) {
    logger.error(e.getMessage(),e);
  }
 
 }