<!-- 注册string和json解析适配器 -->

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">

        <property name="messageConverters">

            <list>

                <bean class="org.springframework.http.converter.StringHttpMessageConverter"/>

                <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"/>

            </list>

        </property>

    </bean>

 <!-- 注册springmvc核心控制器-->

    <servlet>

        <!--servlet-name的值对应一个文件：/WEB-INF/DispatcherServlet-servlet.xml   -->

        <servlet-name>springmvc</servlet-name>

        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <init-param>

            <!-- 指定application.xml文件 -->

            <param-name>contextConfigLocation</param-name>

            <param-value>classpath:springmvc.xml</param-value>

        </init-param>

        <load-on-startup>1</load-on-startup>

    </servlet>

    <servlet-mapping>

        <servlet-name>springmvc</servlet-name>

        <!--  <url-pattern>*.action</url-pattern>-->

        <!--默认匹配所有请求-->

        <!--Spring MVC将捕获Web容器所有的请求，包括静态资源的请求，Spring MVC会将它们当成一个普通请求处理-->

        <url-pattern>/</url-pattern>

    </servlet-mapping>

<!-- 配置SpringMVC -->

    <!-- 1.开启SpringMVC注解模式 -->

    <!-- 简化配置：

        (1)自动注册DefaultAnootationHandlerMapping,AnotationMethodHandlerAdapter

        (2)提供一些列：数据绑定，数字和日期的format @NumberFormat, @DateTimeFormat, xml,json默认读写支持

    -->

    <mvc:annotation-driven/>

    <!--

    静态资源交给servlet处理，

    在springMVC-servlet.xml中配置<mvc:default-servlet-handler />后，

    会在Spring MVC上下文中定义一个org.springframework.web.servlet.resource.DefaultServletHttpRequestHandler，

    它会像一个检查员，对进入DispatcherServlet的URL进行筛查，

    如果发现是静态资源的请求，就将该请求转由Web应用服务器默认的Servlet处理，

    如果不是静态资源的请求，才由DispatcherServlet继续处理。

    -->

    <mvc:default-servlet-handler/>

package com.eggtwo.euq.interceptor;

import com.eggtwo.euq.dto.CurrentSysUser;

import com.eggtwo.euq.utils.CacheUtil;

import com.eggtwo.euq.utils.ConfigUtil;

import com.eggtwo.euq.utils.CookieUtil;

import org.springframework.web.servlet.HandlerInterceptor;

import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

import java.io.PrintWriter;

public class LoginInterceptor implements HandlerInterceptor {

    private boolean isAjaxRequest(HttpServletRequest request) {

        if (request.getHeader("x-requested-with") != null && request.getHeader("x-requested-with").equalsIgnoreCase("XMLHttpRequest")) {

            //如果是ajax请求响应头会有，x-requested-with

            System.out.print("发生ajax请求...");

            return true;

        }

        return false;

    }

    @Override

    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        String requestUri = request.getRequestURI(); //请求完整路径，可用于登陆后跳转

        String contextPath = request.getContextPath();  //项目下完整路径

        String url = requestUri.substring(contextPath.length()); //请求页面

        System.out.print("发生拦截...");

        System.out.println("来自：" + requestUri + "的请求");

        //拿到cookie

        //也就是获取session里的登录状态值

        String cookieKey = ConfigUtil.getBossCookieKey();

        String cookieValue = CookieUtil.getByName(request, cookieKey);

        CurrentSysUser currentSysUser =null;

        String errorMsg=null;

        if (cookieValue == null) {

            errorMsg="no login,please login";

        }else{

            currentSysUser = CacheUtil.getT(cookieValue);

            if (currentSysUser == null) {

                errorMsg="no login,please login";

            }

        }

        if (errorMsg!=null){

            if (isAjaxRequest(request)) {

                response.setContentType("application/json; charset=utf-8");

                PrintWriter writer = response.getWriter();

                writer.print("{type:0,msg:'"+errorMsg+"'}");

                writer.close();

                response.flushBuffer();

            } else {

                String basePath= request.getContextPath();

                response.sendRedirect(basePath+"/account/login?error="+errorMsg);

            }

            return false;//返回false不走下面的方法

        }

        //更新缓存过期时间

        CacheUtil.remove(cookieValue);

        CacheUtil.set(cookieValue, currentSysUser, ConfigUtil.getBossCookieTimeoutSecond());

        //更新cookie过期时间--覆盖原有的cookie

        CookieUtil.deleteCookie(response, cookieKey);

        //写入cookie

        CookieUtil.addCookie(response, cookieKey, cookieValue, ConfigUtil.getBossCookieTimeoutSecond());

        return true;

    }

    @Override

    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override

    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }

}

 <!--配置拦截器, 多个拦截器,顺序执行 -->

    <mvc:interceptors>

        <mvc:interceptor>

            <!-- 先匹配所有路径，然后排除不需要检查的路径 -->

            <mvc:mapping path="/**"/>

            <!--不拦截的action-->

            <mvc:exclude-mapping path="/account/login"/>

            <mvc:exclude-mapping path="/account/logout"/>

            <!-- 网站的登录路径是 "http://localhost:8080/cultivate-job/"

                路径path="/"表示的路径就是网站入口路径,

                也就是说拦截器只方向两种请求:

                1. 错误页面,直接访问jsp页面,这些页面不在WEB-INF目录下,可以直接访问

                2. 网站入口请求,检查到没有登录,会重定向到网站入口路径,再被定向到登录页面

            -->

            <mvc:exclude-mapping path="/"/>

            <!-- 以下是静态资源 -->

            <mvc:exclude-mapping path="/content/**" />

            <mvc:exclude-mapping path="/images/**" />

            <mvc:exclude-mapping path="/js/**" />

            <mvc:exclude-mapping path="/css/**" />

            <mvc:exclude-mapping path="/upload/**" />

            <mvc:exclude-mapping path="/download/**" />

            <!-- 自定义拦截器路径 -->

            <bean class="com.eggtwo.euq.interceptor.LoginInterceptor"></bean>

        </mvc:interceptor>

        <!-- 当设置多个拦截器时，先按顺序调用preHandle方法，然后逆序调用每个拦截器的postHandle和afterCompletion方法 -->

    </mvc:interceptors>