cookie自动登录，没法删除

if(getAutologin().equals("on")){                Cookie usernamecookie = new Cookie("usernamecookies", getUsername().trim());                usernamecookie.setMaxAge(60*60*24*7); // 设置Cookie有效期为                usernamecookie.setPath("/");                response.addCookie(usernamecookie);                  Cookie passwordcookie = new Cookie("passwordcookies", MD5.MD5Password(getPasswd()).trim());                   passwordcookie.setMaxAge(60*60*24*7);                 usernamecookie.setPath("/");                response.addCookie(passwordcookie);              }

Cookie cookies[] = request.getCookies() ;                logger.info(cookies.length);               Cookie c = null ;      for(int i=0;i<cookies.length;i++){           c = cookies[i] ;           if(c.getName().equals("usernamecookies")){                              Cookie cookie = new Cookie("usernamecookies", null);                 cookie.setMaxAge(0);                 cookie.setPath("/");//根据你创建cookie的路径进行填写                     response.addCookie(cookie);             }           if(c.getName().equals("passwordcookies")){                   c.setMaxAge(0) ;               response.addCookie(c) ;     //修改后，要更新到浏览器中               }                             }