spring拦截器(interceptor)简介

1. 拦截器用途

　　（1）拦截未登录用户直接访问某些链接

　　（2）拦截日志信息

　　（3）拦截非法攻击，比如sql注入

2. 涉及jar、类

　　（1）spring-webmvc.jar

　　（2）HandlerInterceptor(org.springframework.web.servlet：接口)、

　　　　  AsyncHandlerInterceptor(org.springframework.web.servlet：接口)、　

　　　　  HandlerInterceptorAdapter(org.springframework.web.servlet.handler.HandlerInterceptorAdapter：抽象类)

3.业务类

　　（1）实现（implements） 实现HandlerInterceptor接口或者子接口

　　（2）继承（extends） 继承HandlerInterceptor接口子类（抽象类）

　　（3）涉及的方法

　　　　  preHandle、postHandle、afterCompletion

4.测试代码

LoginInterceptor

 public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler throws Exception {
 　　LOGGER.info("--------preHandle-------" + request.getRequestURI());
 　　HttpSession session = request.getSession();
 　　String login_account = String.valueOf(session.getAttribute(CommonConstants.SESSION_KEY+session.getId()));
 　　if(!request.getRequestURI().contains("/baselogin/")){
 　　　　if (StringUtils.isBlank(login_account) || "null".equalsIgnoreCase(login_account)) {
 　　　　　　response.sendRedirect("/baselogin/loginPage.htm");
 　　　　　　return false;
 9 　　　　}
 　　}
 　　return true;
 }

 public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)throws Exception {
 　　LOGGER.info("--------postHandle-------" + request.getRequestURI());
 }

 public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
 　　LOGGER.info("--------afterCompletion-------" + request.getRequestURI());
 }

 public void afterConcurrentHandlingStarted(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
23 　　LOGGER.info("--------afterConcurrentHandlingStarted-------" + request.getRequestURI());
 }

执行顺序：preHandle -> controller -> postHandle -> afterCompletion

配置：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:p="http://www.springframework.org/schema/p" xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.2.xsd
    http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
    http://www.springframework.org/schema/aop
    http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
    ">
<!-- 拦截排除
<mvc:interceptors>

        <mvc:interceptor>

　　　　　　<mvc:exclude-mapping path=""/>

　　　　　　<bean class="org.bighead.interceptor.LoginInterceptor" />
 　　　　</mvc:interceptor>
 </mvc:interceptors>

-->

<!-- 拦截登录 -->
    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/*/*.htm"/>
            <bean class="org.bighead.interceptor.LoginInterceptor" />
        </mvc:interceptor>
    </mvc:interceptors>
<beans>