SpringMVC的拦截器(Interceptor)

自定义的拦截器类

package interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 这个类是我们自定义的拦截器类
 *      继承  HandlerInterceptorAdapter
 *      实现  HandlerInterceptor
 */
public class MyInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("到达资源之前执行");
        return true;//返回值true可以放行   返回值false不行啦
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("资源执行之后执行");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("最终执行");
    }
}

ApplicationContext.xml

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <context:component-scan base-package="controller,service,exception"></context:component-scan>
    <mvc:annotation-driven></mvc:annotation-driven>

    <mvc:interceptors>        <--注册拦截器-->
        <mvc:interceptor>
            <mvc:mapping path="/*"/>      <--拦截所有请求-->
            <bean class="interceptor.MyInterceptor"></bean>
        </mvc:interceptor>
        <mvc:interceptor>
            <mvc:mapping path="/*"/>    <--拦截所有请求-->
            <bean class="interceptor.MyInterceptor2"></bean>
        </mvc:interceptor>
    </mvc:interceptors>

</beans>