springMVC-05-拦截器

拦截器

创建一个类

package com.huangxin.order.common.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//拦截器
public class CustomHandlerInterceptor implements HandlerInterceptor {
    /**
     * 在控制器方法调用前执行
     * 返回为是否中断
     * true 表示继续执行
     * false 中断所有操作,并response响应后续操作
     */
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception {
        System.out.println("preHandle...");
        return true;
    }
    /**
     * 在控制器调用之后,可以对视图进一步渲染,修改
     * 可以在modelAndView中加入个人数据,例如时间
     *
     * @param request
     * @param response
     * @param o
     * @param modelAndView
     * @throws Exception
     */
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object o, ModelAndView modelAndView) throws Exception {
        request.setAttribute("hello","hello");
        System.out.println("postHandle...");
    }
    /**
     * 整个请求完成以后调用,例如日志调用
     *
     * @param request
     * @param response
     * @param o
     * @param e
     * @throws Exception
     */
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object o, Exception e) throws Exception {
        System.out.println("afterCompletion...");
    }
}

在springMVC.xml配置

    <!--配置拦截器-->
    <mvc:interceptors>
        <mvc:interceptor>
            <!--拦截url-->
            <mvc:mapping path="/**"/>
            <!--不拦截的url-->
            <mvc:exclude-mapping path="/t"/>
            <!--拦截器-->
            <bean class="com.huangxin.order.common.interceptor.CustomHandlerInterceptor"></bean>
        </mvc:interceptor>
    </mvc:interceptors>

拦截可用于登录请求