session验证登录状况拦截器以及XML配置

/**
 * session拦截器
 *
 */
public class SessionInterceptor implements HandlerInterceptor{


public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
throws Exception {
// TODO Auto-generated method stub

}


public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
throws Exception {
// TODO Auto-generated method stub

}


/**
* 用于验证登录状况的拦截器
*
*/
public boolean preHandle(HttpServletRequest req, HttpServletResponse res, Object arg2) throws Exception {
HttpSession session = req.getSession();
Object obj = session.getAttribute("User");
if(obj == null) {
//没有登录，重定向到登录页面
res.sendRedirect(req.getContextPath()+"/toLogin");
return false;
}
return true;
}

}

spring配置文件

 <mvc:interceptors>
<mvc:interceptor>
<!-- 拦截路径 -->
<mvc:mapping path="/**"/>
<!-- 排除登录相关的请求路径-->
<mvc:exclude-mapping path="/toLogin"/>
<mvc:exclude-mapping path="/login"/>
<!-- 拦截器类的路径地址 -->
<bean class="com.jlzc.scangun.util.SessionInterceptor"/>
</mvc:interceptor>
</mvc:interceptors>