如果您想根据请求知道它是否有效:
request.isRequestedSessionIdValid() orHttpSession sess = request.getSession(false);if (sess != null) { // it's valid}如果您存储了对该会话的引用并需要验证,我会
try { long sd = session.getCreationTime();} catch (IllegalStateException ise) { // it's invalid}


