在此过程中 犯二的以为在js中可以用SimpleDateFormat类，结果是自己把jsp和js弄混淆了
在js中是不能使用java的类库的
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
function getDateDemo()
{
//分别获取年、月、日、时、分、秒
var myDate = new Date();
var year = myDate.getFullYear();
var month = myDate.getMonth() + 1;
var date = myDate.getDate();
var hours = myDate.getHours();
var minutes = myDate.getMinutes();
var seconds = myDate.getSeconds();
//月份的显示为两位数字
if(month < 10 ){
month = "0" + month;
}
if(date < 10 ){
date = "0" + date;
}
//时间拼接
var dateTime = year + "-" + month + "-" + date + "-" + hours + ":" + minutes + ":" + seconds ;
var divNode = document.getElementById("time");
divNode.innerHTML = dateTime;
}
window.setInterval("getDateDemo()",1000);//每隔1秒，调用一次getDateDemo()
</script>
</head>
<body>
<div id="time"></div>
</body>
</html>
原文：http://www.cnblogs.com/tcOnLine/p/4363928.html