Spring mvc interceptor配置拦截器，没有登录跳到登录页

<?xml  version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"  
    xmlns:mvc="http://www.springframework.org/schema/mvc"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans     
        http://www.springframework.org/schema/beans/spring-beans.xsd    
        http://www.springframework.org/schema/context     
        http://www.springframework.org/schema/context/spring-context.xsd    
        http://www.springframework.org/schema/mvc     
        http://www.springframework.org/schema/mvc/spring-mvc.xsd"  
    default-autowire="byName">  
    <!-- auto register Processor -->  
    <context:annotation-config />  
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">  
        <property name="basePackage" value="com.anxin.msapweb.db.mybatis.mapper" />  
    </bean>  
  
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  
        <property name="dataSource" ref="db2dataSource" />  
    </bean>  
  
    <mvc:interceptors>  
        <mvc:interceptor>  
            <!-- 需拦截的地址 -->  
                        <!-- 一级目录 -->  
            <mvc:mapping path="/*.do" />  
            <mvc:mapping path="/*.ajax" />  
            <mvc:mapping path="/*.htm" />  
  
                        <!-- 二级目录 -->  
            <mvc:mapping path="/*/*.do" />  
            <mvc:mapping path="/*/*.ajax" />  
            <mvc:mapping path="/*/*.htm" />  
            <!-- 需排除拦截的地址 -->  
            <mvc:exclude-mapping path="/login.htm"/>  
            <bean class="com.anxin.msapweb.web.interceptor.SecurityInterceptor" />  
        </mvc:interceptor>  
    </mvc:interceptors>  
</beans>  

注：不支持<mvc:mapping path="*.do" /> 

package com.anxin.msapweb.web.interceptor;  
  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
import javax.servlet.http.HttpSession;  
  
import org.springframework.web.servlet.HandlerInterceptor;  
import org.springframework.web.servlet.ModelAndView;  
  
import com.anxin.msapweb.common.Config;  
  
public class SecurityInterceptor implements HandlerInterceptor {  
  
    private static final String LOGIN_URL = "/login.htm";  
  
    @Override  
    public boolean preHandle(HttpServletRequest req, HttpServletResponse res, Object handler) throws Exception {  
        HttpSession session = req.getSession(true);  
        // 从session 里面获取用户名的信息  
        Object obj = session.getAttribute(Config.Passport.SESSION_NAME_LOGIN_RESULT);  
        // 判断如果没有取到用户信息，就跳转到登陆页面，提示用户进行登陆  
        if (obj == null || "".equals(obj.toString())) {  
            res.sendRedirect(LOGIN_URL);  
        }  
        return true;  
    }  
  
    @Override  
    public void postHandle(HttpServletRequest req, HttpServletResponse res, Object arg2, ModelAndView arg3) throws Exception {  
    }  
  
    @Override  
    public void afterCompletion(HttpServletRequest req, HttpServletResponse res, Object arg2, Exception arg3) throws Exception {  
    }  
  
}