crud登陆注销拦截器

登陆

<form action="<%=path%>/login.do" method="post">
用户:<input type="text" name="uname"><br>
   密码:<input type="text" name="password"><br>
     <input type="submit" value="登陆">
   <a href="<%=path%>/jsp/reg.jsp">返回注册</a>

@RequestMapping("login.do")
 public String login(User user,HttpServletRequest request){
 User u = ms.login(user);
  if(u!=null){
  request.getSession().setAttribute("u",u);
   return "redirect:list.do";
   }else{
   return "login";
  }
  }
  注销
  @RequestMapping("out.do")
 public String out(HttpServletRequest request){
 if(request!=null){
   request.getSession().invalidate();
  }
   return "login";
 }
 list页面
  function out(){
 location="<%=path%>/out.do";
}
<marquee><h1>欢迎${sessionScope.u.uname }光临</h1></marquee>
 <input type="button" value="注销" "out()">
 拦截器
 springmvc配置文件中
 <!-- 拦截器的引用 -->
   <mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/**"/> <!-- 拦截的路径 -->
        <mvc:exclude-mapping path="/login.do"/><!-- 不拦截的路径 -->
        <mvc:exclude-mapping path="/out.do"/>
        <mvc:exclude-mapping path="/reg.do"/>
        <bean class="com.my.interceptor.MyInterceptor"/>
           </mvc:interceptor>
  </mvc:interceptors> 
MyInterceptor类中实现HandlerInterceptor
 @Override
 public boolean preHandle(HttpServletRequest request, HttpServletResponse response,Object obj) throws Exception {
  User u = (User) request.getSession().getAttribute("u");
  if(u !=null){
   return true;
  }
  response .sendRedirect("jsp/login.jsp");
  return false;
  }