public void doFilter(ServletRequest arg0, ServletResponse arg1,
            FilterChain arg2) throws IOException, ServletException {
                Session session=null;
        Transaction trans=null;
        try{
            session=HibernateSessionFactory.getSession();
            trans=session.beginTransaction();
            arg2.doFilter(arg0, arg1);
            trans.commit();
        }catch(Exception e){
            e.printStackTrace();
            if(trans!=null)
                trans.rollback();
        }finally{
            HibernateSessionFactory.closeSession();
        }
        System.out.println("响应回去");

------解决方案--------------------

探讨

session.removeAttribute("");
session.invalidate(); 是将session设置为失效