这几个方法谁用过，啥意思？
RT:

System.out.println(req.getRemoteUser());

System.out.println(req.getUserPrincipal());

System.out.println(req.getContentLength());

System.out.println(req.getContentType());

System.out.println(req.getDateHeader(""));

System.out.println(req.getIntHeader("accept"));

System.out.println(req.isUserInRole(""));

------解决方案--------------------
http://jitaguizhao.iteye.com/blog/327286