拦截器类

所在工程：atcrowdfunding-admin-2-component
全类名：com.atguigu.crowd.funding.interceptor.LoginInterceptor

package com.atguigu.crowd.funding.interceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import com.atguigu.crowd.funding.entity.Admin;
import com.atguigu.crowd.funding.util.CrowdFundingConstant;
public class LoginInterceptor extends HandlerInterceptorAdapter {
    // 在操作之前请登录, 但是不要拦截登录页面，登出页面
    public boolean preHandler(HttpServletRequest request,
            HttpServletResponse response,
            Object handler) throws Exception{
        // 通过request对象获取HttpSession对象
                HttpSession session = request.getSession();
                // 从Session域尝试获取已登录用户对象
                Admin admin = (Admin) session.getAttribute(CrowdFundingConstant.ATTR_NAME_LOGIN_ADMIN);
                // 如果没有获取到Admin对象
                if(admin == null) {
                    // 将提示消息存入request域
                    request.setAttribute(CrowdFundingConstant.ATTR_NAME_MESSAGE, CrowdFundingConstant.MESSAGE_ACCESS_DENIED);
                    // 转发到登录页面
                    request.getRequestDispatcher("/WEB-INF/admin-login.jsp").forward(request, response);
                    return false;
                }
                // 如果admin对象有效，则放行继续执行后续操作
                return true;
    }
}

注册拦截器类

所在工程：atcrowdfunding-admin-1-webui
配置文件：spring-web-mvc.xml

<!-- 配置拦截器 -->
<mvc:interceptors>
    <mvc:interceptor>
        <!-- 设置当前拦截器要拦截的路径 -->
        <mvc:mapping path="/**"/>
        <!-- 设置要拦截的路径中的例外，也就是不拦截的路径 -->
        <mvc:exclude-mapping path="/admin/to/login/page.html"/>
        <mvc:exclude-mapping path="/admin/do/login.html"/>
        <mvc:exclude-mapping path="/admin/logout.html"/>
        <!-- 拦截器的bean -->
        <bean class="com.atguigu.crowd.funding.interceptor.LoginInterceptor"/>
    </mvc:interceptor>
</mvc:interceptors>