用jquery生成二级菜单的实例代码

function querySub(id,sid/*选中的项*/){
$.post('${path}/page/article/querySubChannelArticle.action', 
                {'channelId':id},function(data){ 
                    $('select[name="article.subChannel.subId"] option[value!=""]').remove(); 
                    var jsonObj = data;    
                    for ( var i = 0; i < jsonObj.length; i++) { 
                        var $option = $('<option>'); 
                        $option.attr('value',jsonObj[i].subId); 
                        if(jsonObj[i].subId === sid){ 
                            $option.attr('selected',true); 
                        } 
                        $option.text(jsonObj[i].subName); 
                        $('select[name="article.subChannel.subId"]').append($option); 
                    } 
                }); 
        } 

        $(function(){ 
            querySub(<s:property value='article.subChannel.channel.channelId'/>,<s:property value='article.subChannel.subId'/>); 
        });

<tr> 
                    <th>一级栏目</th> 
                          <td valign="middle"> 
                            <s:select id='_channel' list="channelList" listKey="channelId" 
                                listValue="channelName"  
                                key="article.subChannel.channel.channelId" 
                                onchange="querySub(this.value)"></s:select> 
                          </td> 
                 </tr> 
                 <tr> 
                    <th>二级栏目</th> 
                          <td valign="middle"> 
                          <s:select name='article.subChannel.subId' list="{}" headerKey="" headerValue="-请选择-"></s:select> 
                          <!--<s:property value="article.subChannel.subName"/> 
                          --></td> 
                 </tr>

public String querySubChannelArticle(){  
        HttpServletResponse response=getResponse(); 
        HttpServletRequest request=getRequest(); 
        response.setContentType("application/json; charset=UTF-8"); 
        PrintWriter out =null; 
        try { 
            out = response.getWriter(); 

            List<Map<String,Object>> list = new LinkedList<Map<String,Object>>(); 
            if(channelId!=null && !channelId.equals("")){ 
                Channel tmp = new Channel(); 
                tmp.setChannelId(Integer.parseInt(channelId)); 
                subChannelList = subChannelDAO.listSubChannel(tmp); 

                for(Object oo:subChannelList){ 
                    Map<String,Object> obj = new HashMap<String,Object>(); 
                    SubChannel c = (SubChannel)oo; 
                    obj.put("subId", c.getSubId()); 
                    obj.put("subName", c.getSubName()); 
                    list.add(obj); 
                } 
            } 
            String outStr = JsonUtil.toJSONStr(list); 
            out.println(outStr); 
        }catch(Exception e){ 
        e.printStackTrace(); 
        } 
        out.flush(); 
        out.close(); 
        return null; 
    }