jsp中实现倒计时的代码教程

jsp：

<section>还有<b class="day" id="d">10</b>天<b class="hour" id="h">5</b>小时<b class="minute" id="m">5</b>分<b class="second" id="s">5</b>秒</section>  
  
<script type="text/javascript">  
    $(document).ready(xc);  
    function xc(){  
            var js_date=${starttime }; //结束时间 可以从数据库中读出来  
        var now_date=new Date().getTime();   
        xc_day=parseInt((js_date-now_date)/1000/60/60/24);  
        xc_h=parseInt((js_date-now_date)/1000/60/60-24*xc_day);  
        xc_m=parseInt((js_date-now_date)/1000/60-xc_day*24*60-xc_h*60);  
        xc_s=parseInt((js_date-now_date)/1000-xc_m*60-xc_h*60*60-xc_day*24*60*60);  
        document.getElementById("d").innerHTML=xc_day;  
        document.getElementById("h").innerHTML=xc_h;  
        document.getElementById("m").innerHTML=xc_m;  
        document.getElementById("s").innerHTML=xc_s;  
        setTimeout("xc()",1000);  
        }  
</script>  

java：

Long starttime = selectionCycle.getStart_time().getTime();  
ServletActionContext.getRequest().setAttribute("starttime ",starttime );