Filter实现登录功能限制

public void doFilter(ServletRequest arg0,ServletResponse arg1,FilterChain chain) throws IOException, ServletException{HttpServletRequest req=(HttpServletRequest)arg0;HttpServletResponse resp=(HttpServletResponse)arg1;Object user=req.getSession().getAttribute("user");String uri=req.getRequestURI();String url=req.getRequestURL().toString();System.out.println("SecurityFilter  uei=========="+uri);System.out.println("SecurityFilter  url++++++++++"+url);//用户想要进入登录页面和用户需要提交的登录数据if("/test/hello.jsp".equals(uri)||"/test/my".equals(uri)){//用户在提交登录的信息chain.doFilter(arg0, arg1);}else if(user==null){//没有登录resp.sendRedirect("hello.jsp");}else{//登录了系统，可以访问chain.doFilter(arg0, arg1);}}