Spring中使用Interceptor拦截器拦截请求

本文实现一个基于Spring4.0的Interceptor拦截Controller请求的demo。更多的详细介绍在后续完善。

1、实现HandlerInterceptor接口

本例中的BaseInterceptor类HandlerInterceptor，并实现两个自定义的接口用来分发get和post请求处理。子类通过继承BaseInterceptor类然后重载其中关心的方法来拦截处理不同的请求。你也可以直接实现HandlerInterceptor并在对应的方法中直接进行拦截请求处理。

BaseInterceptor.java代码如下：

import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.web.servlet.HandlerInterceptor;import org.springframework.web.servlet.ModelAndView;import com.landsem.update.base.interceptors.IGetInterceptor;import com.landsem.update.base.interceptors.IPostInterceptor;public abstract class BaseInterceptor implements HandlerInterceptor,IGetInterceptor, IPostInterceptor {@Overridepublic final void afterCompletion(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, Exception arg3)throws Exception {// do getif (arg0.getMethod().equalsIgnoreCase("get")) {afterGetHandlerCompletion(arg0,arg1,arg2,arg3);}// do postelse if (arg0.getMethod().equalsIgnoreCase("post")) {afterPostHandlerCompletion(arg0,arg1,arg2,arg3);}}@Overridepublic final void postHandle(HttpServletRequest arg0, HttpServletResponse arg1,Object arg2, ModelAndView arg3) throws Exception {// do getif (arg0.getMethod().equalsIgnoreCase("get")) {postGetHandle(arg0,arg1,arg2,arg3);}// do postelse if (arg0.getMethod().equalsIgnoreCase("post")) {postPostHandle(arg0,arg1,arg2,arg3);}}@Overridepublic final boolean preHandle(HttpServletRequest arg0, HttpServletResponse arg1,Object arg2) throws Exception {// do getif (arg0.getMethod().equalsIgnoreCase("get")) {return preGetHandle(arg0, arg1, arg2);}// do postelse if (arg0.getMethod().equalsIgnoreCase("post")) {return prePostHandle(arg0, arg1, arg2);}// defaultreturn true;}@Overridepublic void afterGetHandlerCompletion(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, Exception arg3) {// TODO Auto-generated method stub}@Overridepublic void postGetHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, ModelAndView arg3)throws Exception {// TODO Auto-generated method stub}@Overridepublic boolean preGetHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2) throws Exception {// TODO Auto-generated method stubreturn true;}@Overridepublic void afterPostHandlerCompletion(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, Exception arg3) {// TODO Auto-generated method stub}@Overridepublic void postPostHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, ModelAndView arg3)throws Exception {// TODO Auto-generated method stub}@Overridepublic boolean prePostHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2) throws Exception {// TODO Auto-generated method stubreturn true;}}

IGetInterceptor.java代码如下：

import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.web.servlet.ModelAndView;public interface IGetInterceptor {public void afterGetHandlerCompletion(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, Exception arg3);public void postGetHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, ModelAndView arg3)throws Exception;public boolean preGetHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2) throws Exception;}

IPostInterceptor.java的代码如下：

import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.web.servlet.ModelAndView;public interface IPostInterceptor {public void afterPostHandlerCompletion(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, Exception arg3);public void postPostHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, ModelAndView arg3)throws Exception;public boolean prePostHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2) throws Exception;}

DemoInterceptor.java是一个实现拦截post请求的类示例：

import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.log4j.Logger;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.servlet.ModelAndView;import com.landsem.update.base.interceptors.impl.BaseInterceptor;import com.landsem.update.cache.service.ICacheService;public class DemoInterceptor extends BaseInterceptor {protected static Logger logger = Logger.getLogger(Demo .class);@Overridepublic void afterPostHandlerCompletion(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, Exception arg3) {if (logger.isDebugEnabled()) {logger.debug("Demo afterCompletion");}}@Overridepublic void postPostHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2, ModelAndView arg3)throws Exception {if (logger.isDebugEnabled()) {logger.debug("PublishUpdateInterceptor postPostHandle");}}@Overridepublic boolean prePostHandle(HttpServletRequest arg0,HttpServletResponse arg1, Object arg2) throws Exception {if (logger.isDebugEnabled()) {logger.debug("PublishUpdateInterceptor prePostHandle");}return true;}}

2、在XML配置文件中配置拦截器

本例中使用一个独立的文件applicationContext-interceptors.xml用于描述工程中的拦截器，在web.xml中配置解析该配置文件。

applicationContext-interceptors.xml文件内容如下：

<?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:p="http://www.springframework.org/schema/p"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"xmlns:jee="http://www.springframework.org/schema/jee"xmlns:tx="http://www.springframework.org/schema/tx"xmlns:mvc="http://www.springframework.org/schema/mvc"    xsi:schemaLocation="          http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsdhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsdhttp://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.0.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsdhttp://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">  <mvc:interceptors>      <!-- 使用bean定义一个Interceptor，直接定义在mvc:interceptors根下面的Interceptor将拦截所有的请求 -->      <!--    <bean class="com.arvinfei.springmvc.DemoInterceptor"/> -->            <mvc:interceptor>                 <mvc:mapping path="/manage/test.shtml"/><pre name="code" class="html">               <mvc:mapping path="/manage/test2.shtml"/>

  <!-- 定义在mvc:interceptor下面的表示是对特定的请求才进行拦截的 --> <bean class="com.arvinfei.springmvc.DemoInterceptor"/> </mvc:interceptor> </mvc:interceptors> </beans>

上面的配置DemoInterceptor将拦截/manage/test.shtml和/manage/test.shtml的post请求。

web.xml中指定所有以applicationContext-开头的配置文件，主要内容如下：

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0">  <display-name></display-name>  <context-param>    <param-name>contextConfigLocation</param-name>    <param-value>classpath:applicationContext-*.xml</param-value>  </context-param>  <servlet>    <servlet-name>spring</servlet-name>    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>    <init-param>      <param-name>contextConfigLocation</param-name>      <param-value>/WEB-INF/classes/spring-servlet.xml</param-value>    </init-param>    <load-on-startup>1</load-on-startup>  </servlet>  <servlet-mapping>    <servlet-name>spring</servlet-name>    <url-pattern>*.shtml</url-pattern>  </servlet-mapping>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list></web-app>

关于SpringMVC中拦截器的更多较为详细的介绍可以参考如下博客：

http://itindex.net/detail/50153-springmvc-interceptor