request.getSession()、request.getSession(false)和request.getSession(true)的区别
request.getSession()、request.getSession(false)和request.getSession(true)的区别：
在J2EE的API文档中关于HttpSession getSession(boolean create)的说明是：
Returns the current HttpSession associated with this request or, if there is no current session and create is true, returns a new session.
而对于HttpSession getSession()的说明是：
Returns the current session associated with this request, or if the request does not have a session, creates one.
由此可见：request.getSession()和request.getSession(true)是等价的。
