工作問題之JQUERY.JSON請求數據問題

/**
     * list頁面查詢操作
     * @param cell
     * @return
     */
    @RequestMapping(value="schedule/getLists.jhtml")
    public @ResponseBody Object getLists(Model model, Schedule s,String gradeid,String classid){
        String schoolid=getCompanyid();
        String uid = getUid();
        System.out.println("getList=================="+gradeid);
        System.out.println("getList=================="+classid);
        Object[] args = new Object[]{schoolid,gradeid,classid};
        List<Schedule> lists = ics.queryBySql(Schedule.class, args);
        if(lists.size()==0){
            return 0;
        }else{
        String title = lists.get(0).getCoursetitle();
        //model.addAttribute("classid",classid);
        model.addAttribute("title",title);
       /* model.addAttribute("datalist",lists);*/
            //JacksonUtils ju = new JacksonUtils();
            /*String sche = ju.writeObj2Str(su);*/
        return lists;}

    }

spring mvc獲取數據

==============================================================

 jQuery.ajax({
            url: path + "/schedule/getLists.jhtml",
            data: {gradeid: $("#gradeid").val(), classid: $("#classid").val()}, // 從表單中獲取數據
            type: "POST",
            error: function(request) {      // 設置表單提交出錯
                alert("暫無數據");
            },
            success: function(data) {
                $("#thead").empty();
                $("#tbody").empty();
                $("#title").empty();
                var head = " <tr><td>&nbsp;</td><td>星期一</td><td>星期二</td><td>星期三</td><td>星期四</td><td>星期五</td><td>星期六</td><td>星期日</td></tr>";
                $(head).appendTo($("#thead"));
                if(data == 0 ){
                    $("#title").empty();
                    var divs = " <div class='curriculum_con'><img src='${spath }/register_pay/images/record_w.jpg' width='153' height='304' /></div>";
                    $(divs).appendTo($("#title"));
                    $("#thead").empty();
                }
                
                
                //alert(data);//2173
                var obj  = $.parseJSON(data);
                //alert(obj.length);//8
                if(obj.length>-1){
                    var title = "<h2>"+obj[0].coursetitle+"</h2>";
                    $(title).appendTo($("#title"));
                }
                //alert(title);
                var strs = "";
                for (var i = 0; i < obj.length; i++) {
                    //scoreid uid userno tname  score
                    var schedule = obj[i];
                    var str = "<tr><td>"+schedule.section+"<br />("+schedule.begintime +"-"+schedule.endtime +")</td><td>"+schedule.monday +"</td><td>"+schedule.tuesday +"</td><td>"+schedule.wednesday +"</td><td>"+schedule.thursday +"</td><td>"+schedule.friday +"</td><td>"+schedule.saturday +"</td><td>"+schedule.sunday +"</td></tr>";
                    strs += str;
                }
                $(strs).appendTo($("#tbody"));
            }
        });

javascript 代碼：

問題很奇葩，當我在後臺將LIST數據轉換成JSON字符串傳到前端後，$.parseJSON('data')，將JSON字符串轉換成JSON對象後，循環遍歷時它並不是對象格式，而是單個字符，後來在後臺直接將LIST對象傳過來，在這邊使用$.parseJSON("data"),方法轉換成字符串就能正常解析。不知道什麼原因