小弟我SSh弄到一起，现在想设计一个FILter过滤器反而不行啦

public class GetCUIListen  implements Filter{    private HttpServletRequest httpServletRequest;        @Override    public void destroy() {        // TODO Auto-generated method stub            }    @Override    public void doFilter(ServletRequest arg0, ServletResponse arg1,            FilterChain arg2) throws IOException, ServletException {        // TODO Auto-generated method stub        httpServletRequest=(HttpServletRequest)arg0;        User user;        if(httpServletRequest.getSession().getAttribute("currentUser")==null&&(user=getUser())!=null)           httpServletRequest.getSession().setAttribute("currentUser",user );        System.out.println("doFilter");        arg2.doFilter(arg0, arg1);            }    private User getUser() {        // TODO Auto-generated method stub    //        System.out.println(hibernateTemplate==null);  //我本来想spring注入进来的，可是不对//        session.beginTransaction();//        User user=(User) session.load(User.class, "wubuqilai@gmail.com");//        session.getTransaction().commit();//        session.close();//        return user;        return null;    }    @Override    public void init(FilterConfig arg0) throws ServletException {        // TODO Auto-generated method stub        System.out.println("init");    }       }