A web application uses the HttpSession mechanism to determine if a user is "logged in." When a usersupplies a valid user name and password， an HttpSession is created for that user. The user has access tothe application for only 15 minutes after logging in. The code must determine how long the user has beenlogged in， and if this time is greater than 15 minutes， must destroy the HttpSession. Which method in HttpSession is used to accomplish this？（）
A、Getcreationtime
B、Invalidateafter
C、Getlastaccessedtime
D、Getmaxinactiveinterval
简述计算机软件工程结构化分析SA方法的步骤。
以下哪项不是正确培养积极形态的方法？（）
A、当心里觉得有太多压力时选择适当场合大声歌唱、大声叫喊
B、经常重复回忆客户投诉自己的经历，提醒自己注意
C、经常自我安慰生活中遇到不知道的事情是很正常的
D、我对自己不过分苛求，对他人也不会期望过高
两台设备利用红外传输的有效操作距离是（）。
A、10米
B、5米
C、1米
D、20米
软件设计的任务是什么？
Which statement is true about web container session management？（）
A、Access to session-scoped attributes is guaranteed to be thread-safe by the web container.
B、To activate URL rewriting， the developer must use the HttpServletResponse.setURLRewriting method.
C、If the web application uses HTTPS， then the web container may use the data on the HTTPS request stream to identify the client.
D、The JSESSIONID cookie is stored permanently on the client so that a user may return to the web application and the web container will rejoin that session.