JavaScript Ajax Json实现上下级下拉框联动效果实例代码

<div class="forntName">部门</div>
 <div class="inpBox">
 <SELEct  name="department" id="department"  onchange="change();" style="width:200px;" >
 <option value='-1'>请选择</option>
 <s:iterator value="departmentList">
  <option value='<s:property value="departmentCode"/>'><s:property value="departmentName"/></option>
 </s:iterator>
 <SELEct> 
 </div>
<SPAN style="WHITE-SPACE: pre"> </SPAN><div class="forntName">人员</div>
 <div class="inpBox">
 <SELEct name="workorderOperator" id = "workorderOperator" style="width:200px;">

 <s:iterator value="userList">
  <option value='<s:property value="userName"/>'><s:property value="userName"/></option>
 </s:iterator>
 </SELEct>
 </div>

<script type="text/javascript">
function change(){    
    var departmentCode =$("#department").val(); 

    var params = { 
        'departmentCode':departmentCode 
    }; 
    $.ajax({
        type: 'get',
        url: "departmentChangeEvent.shtml",
        cache: false,
        data: params,
        dataType: 'json',
        success: function(data){
      var sel2 = $("#workorderOperator"); 
      sel2.empty(); 
      if(data==null)
          {
       sel2.append("<option value = '-1'>"+"部门人员为空"+"</option>");
          }
      var items=data.list;
      if(items!=null)
         {
        for(var i =0;i<items.length;i++)
           {
            var item=items[i];
            sel2.append("<option value = '"+item.userName+"'>"+item.userChinesename+"</option>");
           };
          }    
      else
          {
       sel2.empty(); 
          }
        },
        error: function(){
            return;
        }
    });
    //$.post(url,params,callBACk); 
} 
</script> 

public String departmentChangeEvent() throws Exception{
  userList=service.queryForList("Workorder.queryUserByDepartmentCode",departmentCodE);
  if(userList!=null&&userList.size()>0)
  {
   httpServletResponse response = ServletActionContext.getResponse();
   response.setContentType("text/html;charset=utf-8");
   response.setHeader("Pragma","No-cache");
   response.setHeader("Cache-Control","no-cache");
   response.setHeader("Cache-Control","no-store");
   PrintWriter writer = response.getWriter();
   JSONObject json = new JSONObject();
   Map map = new HashMap();
      map.put("list",userList);
      JSONObject jso = JSONObject.fromObject(map);
   writer.write(jso.toString());
      writer.flush();
      writer.close();  }
         return null; 
   } 

<STRONG> JSONObject jso = JSONObject.fromObject(map);</STRONG> 

  <action name="departmentChangeEvent" class="workorderAction" method="departmentChangeEvent">
       <result type="json">
   </result> 
        </action>