<mvc:annotation-driven>        <mvc:message-converters register-defaults="true">            <!-- 将StringHttpMessageConverter的默认编码设为UTF-8 -->            <bean class="org.springframework.http.converter.StringHttpMessageConverter">                <constructor-arg value="UTF-8" />            </bean>            <!-- Spring默认Json转换器 -->            <bean                class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">                <property name="prettyPrint" value="true" />            </bean>                  </mvc:message-converters>    </mvc:annotation-driven>