1、建立攔截器

public class PowerInterceptor extends HandlerInterceptorAdapter {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        // TODO Auto-generated method stub

        HttpSession session = request.getSession();

        Myemp emp 
 
= (Myemp) session.getAttribute(Constrains.LOGIN_USER);
        if (emp == null) {
            response.sendRedirect(request.getContextPath()+"/index.jsp");
            return false;
        }

        return super.preHandle(request, response, handler);
    }

}

2、添加註解

<mvc:interceptors>
        <
 
mvc:interceptor>
            <mvc:mapping path="/**"/>
            <mvc:exclude-mapping path="/login"/>
            <mvc:exclude-mapping path="/js/**"/>
            <mvc:exclude-mapping path="/css/**"/>
            <mvc:exclude-mapping path="/font/**"/>
            <mvc:exclude-mapping 
 
path="/images/**"/>
            <mvc:exclude-mapping path="/layer/**"/>
            <mvc:exclude-mapping path="/layui/**"/>
            <mvc:exclude-mapping path="/login"/>
            <bean class="com.cc.house.web.interceptor.PowerInterceptor"></bean>
        </mvc:interceptor>
    </mvc:interceptors>