<bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">

                <property name="supportedMediaTypes">

                    <list>

                        <value>text/html;charset=UTF-8</value>

                        <value>application/json</value>

                    </list>

                </property>

                <property name="features">

                    <list>

                        <value>WriteMapNullValue</value>

                        <value>QuoteFieldNames</value>

                        <value>WriteNullListAsEmpty</value>

                        <value>WriteNullStringAsEmpty</value>

                        <value>WriteNullNumberAsZero</value>

                        <value>DisableCircularReferenceDetect</value>

                    </list>

                </property>

            </bean>

    QuoteFieldNames----------输出key时是否使用双引号,默认为true

    WriteMapNullValue--------是否输出值为null的字段,默认为false

    WriteNullNumberAsZero----数值字段如果为null,输出为0,而非null

    WriteNullListAsEmpty-----List字段如果为null,输出为[],而非null

    WriteNullStringAsEmpty---字符类型字段如果为null,输出为"",而非null

    WriteNullBooleanAsFalse--Boolean字段如果为null,输出为false,而非null