到这段时，

想起来了以前学底层一些的servlet & jsp技术时，

过滤器和拦截器也有相关实现，

但比起来，spring的实现，可用性高很多。

其它代码不再放上来，

只放拦截器实现和xml配置吧。

AuthorizationInterceptor.java

package org.fkit.interceptor;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.fkit.domain.User;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;public class AuthorizationInterceptor implements HandlerInterceptor {private static final String[] IGNORE_URI = {"/loginForm", "/login"};@Overridepublic void afterCompletion(HttpServletRequest request,HttpServletResponse response, Object Handler, Exception exception) throws Exception {System.out.println("AuthorizationInterceptor afterCompletion-->");}@Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView mv)throws Exception {// TODO Auto-generated method stubSystem.out.println("AuthorizationInterceptor postCompletion-->");}@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {// TODO Auto-generated method stubSystem.out.println("AuthorizationInterceptor preCompletion-->");boolean flag = false;String servletPath = request.getServletPath();for (String s : IGNORE_URI) {if (servletPath.contains(s)) {flag = true;break;}}if (!flag) {User user = (User) request.getSession().getAttribute("user");if (user == null ) {System.out.println("AuthorizationInterceptor拦截讲求：");request.setAttribute("message", "请先登陆再访问网站");request.getRequestDispatcher("loginForm").forward(request, response);} else {System.out.println("AuthorizationInterceptor 放行请求：");flag = true;}}return flag;}}

springmvc-config.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:mvc="http://www.springframework.org/schema/mvc"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans-4.2.xsdhttp://www.springframework.org/schema/mvchttp://www.springframework.org/schema/mvc/spring-mvc-4.2.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context-4.2.xsd"><context:component-scan base-package="org.fkit.controller"/><mvc:annotation-driven /><mvc:default-servlet-handler/><mvc:interceptors><mvc:interceptor><mvc:mapping path="/*"/><bean class="org.fkit.interceptor.AuthorizationInterceptor" /></mvc:interceptor></mvc:interceptors><bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"><property name="prefix"><value>/WEB-INF/content/</value></property><property name="suffix"><value>.jsp</value></property></bean><bean id="multipartResolver"class="org.springframework.web.multipart.commons.CommonsMultipartResolver"><property name="maxUploadSize"><value>10285760</value></property>  <property name="defaultEncoding"><value>UTF-8</value></property></bean></beans>