如果需要在html页面上设置不缓存，请在<head>标签中加入如下语句：
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
详细介绍可看：
http://blog.csdn.net/m0_38073829/article/details/75453050
http://www.cnblogs.com/liuling/p/2013-7-25-01.html