jsp中判断权限，若没有登录，则不能访问

在jsp中加

<jsp:include page="permission_adminfilter.jsp"/>

permission_adminfilter.jsp中内容如下：

<%@ page language="java" contentType="text/html;charset=GBK" %>

<%

request.setCharacterEncoding("GBK");

String loginUserName = (String)session.getAttribute("session_loginname");

if(!"admin".equals(loginUserName)){

%>

<script language="JavaScript" type="text/javascript">

alert("您无权访问该页面！");

top.location.href="../index.jsp";

</script>

<%

}

%>