Spring的jackson2.x的Date格式化

参考：http://my.oschina.net/u/818540/blog/223052

jackson 2.x关于时间格式化 比1.x 方便了很多，修改MappingJackson2HttpMessageConverter中DateFormat的patten：

<mvc:annotation-driven>

    <mvc:message-converters>

        <beanclass="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">

            <propertyname="objectMapper">

                <beanclass="com.fasterxml.jackson.databind.ObjectMapper">

                    <propertyname="dateFormat">

                        <beanclass="java.text.SimpleDateFormat">

                            <constructor-argtype="java.lang.String"value="yyyy-MM-dd HH:mm:ss"/>

                        </bean>

                    </property>

                </bean>

            </property>

        </bean>

    </mvc:message-converters>

</mvc:annotation-driven>