request.getSession()与this.getServletContext()有什么区别

request.getSession().setAttribute和request.setAttribute的区别是什么? request.getSession()与this.getServletContext()有什么区别 request.getSession().setAttribute(User,user);这句话表示什么意思 request.getsession().setAttribute()和session.setAttribute()有什么区别? request.getSession().getServletContext().getRequestDispatcher(/expot).forward(request,response);这句话的意思是什么? filter过滤器如何获得值loginservlet中 HttpSession session = request.getSession(); userRight=true; session.setAttribute(checkRight,userRight); filter中 HttpSession session = request.getSession(); String str=(String)session.getAttribute(c String filePath = request.getSession().getServletContext().getRealPath(/);请问这句话返回的路径是什么,解释下getRealPath(/)函数中的/表示什么意思, java.lang.ClassCastException:info.ShopBean at java.util.TreeMap.compare(Unknown Source) at java.utresponse.setContentType(text/html;setchar:UTF-8);PrintWriter out = response.getWriter();HttpSession session = request.getSession();Set set = new TreeS request support prospectus request request翻译 request是什么意思 Bad Request . request.getParameterMap() request是什么意思 request.getParameterMap() request是什么意思 request received