springmvc 4.x 转json

<bean
        class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="mappingJackson2HttpMessageConverter" />
            </list>
        </property>
    </bean>

    <bean id="mappingJackson2HttpMessageConverter"
        class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>application/json;charset=UTF-8</value>
                <value>text/html;charset=UTF-8</value>
                <value>text/json;charset=UTF-8</value>
            </list>
        </property>
    </bean>