java @ResponseBody返回值中去掉NULL字段

<mvc:annotation-driven>
<mvc:message-converters register-defaults="true">
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean class="com.fasterxml.jackson.databind.ObjectMapper">
<property name="dateFormat">
<bean class="java.text.SimpleDateFormat">
<constructor-arg type="java.lang.String" value="yyyy-MM-dd HH:mm:ss" />
</bean>
</property>
<property name="serializationInclusion">
<util:constant static-field="com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL" />
</property>
</bean>
</property>
</bean>
</mvc:message-converters>
</mvc:annotation-driven>

<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<property name="messageConverters">
<list>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
<property name="objectMapper">
<bean id="jacksonObjectMapper" class="com.fasterxml.jackson.databind.ObjectMapper">
<property name="dateFormat">
<bean class="java.text.SimpleDateFormat">
<constructor-arg type="java.lang.String" value="yyyy-MM-dd HH:mm:ss" />
</bean>
</property>
<property name="serializationInclusion">
<util:constant static-field="com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL" />
</property>
</bean>
</property>
<property name="supportedMediaTypes">
<list>
<value>application/json;charset=UTF-8</value>
<value>application/x-www-form-urlencoded</value>
</list>
</property>
</bean>
<bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter">
<property name="supportedMediaTypes">
<list>
<value>image/jpeg</value>
<value>image/png</value>
</list>
</property>
</bean>
</list>
</property>
</bean>