设置过期
<session-config>
<session-timeout>30</session-timeout>
</session-config>
编码方式
HttpSession session = request.getSession( );
session.setMaxInactiveInterval(20 * 60);//20分钟后过期
跟踪
<%@page contentType="text/html"%>
<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jstl/fmt" prefix="fmt" %>
<html>
<head><title>View Session JSP </title></head>
<body>
<h2>Session Info From A JSP</h2>
The session ID: <c:out value="${pageContext.session.id}"/>
<h3>Session date values formatted as Dates</h3>
<jsp:useBean id="timeValues" class="java.util.Date"/>
<c:set target="${timeValues}" value=
"${pageContext.session.creationTime}" property="time"/>
The creation time: <fmt:formatDate value="${timeValues}" type="both"
dateStyle="medium" /><br><br>
<c:set target="${timeValues}" value=
"${pageContext.session.lastAccessedTime}" property="time"/>
The last accessed time: <fmt:formatDate value="${timeValues}" type=
"both" dateStyle="short" />
</body>
</html>