web.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:p="http://www.springframework.org/schema/p"
   xmlns:context="http://www.springframework.org/schema/context"
   xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" xmlns:mvc="http://www.springframework.org/schema/mvc"
   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <context:property-placeholder location="classpath:config/application.properties" />

   <context:component-scan base-package="com.<!--扫描对应的包-->"></context:component-scan>

   <!--识别springmvc注解-->
   <mvc:annotation-driven>
     <mvc:message-converters register-defaults="true">
       <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">  
         <property name="supportedMediaTypes" value="application/json"/>
         <property name="features">
           <array>
             <value>WriteMapNullValue</value>
             <value>WriteDateUseDateFormat</value>
           </array>
         </property>
       </bean>
     </mvc:message-converters>  
   </mvc:annotation-driven>

</beans>