將object轉為Json時避免出現"$ref"

SerializerFeature.DisableCircularReferenceDetect是用來禁止循環引用檢測的。

正確的配置

1、springboot

public class AppWebConfig implements WebMvcConfigurer

    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        FastJsonHttpMessageConverter fastConverter = new FastJsonHttpMessageConverter();
        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        fastJsonConfig.setSerializerFeatures(
                SerializerFeature.PrettyFormat,
                SerializerFeature.DisableCircularReferenceDetect
        );
        List<MediaType> mediaTypes = new ArrayList<>();
        mediaTypes.add(MediaType.APPLICATION_JSON_UTF8);
        fastConverter.setSupportedMediaTypes(mediaTypes);
        fastConverter.setFastJsonConfig(fastJsonConfig);
        converters.add(fastConverter);
    }

2、spring-servlet.xml

    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="false">
            <!--把ByteArray加在Json前面-->
            <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter">
                <property name="supportedMediaTypes">
                    <list>
                        <value>application/json;charset=UTF-8</value>
                        <value>text/plain;charset=UTF-8</value>
                    </list>
                </property>
            </bean>
            <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
                <property name="features">
                    <list>
                        <value>DisableCircularReferenceDetect</value>
                    </list>
                </property>
                <property name="supportedMediaTypes">
                    <list>
                        <value>application/json;charset=UTF-8</value>
                        <value>text/plain;charset=UTF-8</value>
                    </list>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>`