@Configuration
public class WebMvcConfig extends WebMvcConfigurationSupport {
 public FastJsonHttpMessageConverter fastJsonHttpMessageConverter() {
        FastJsonHttpMessageConverter fastJsonHttpMessageConverter = new FastJsonHttpMessageConverter();

        FastJsonConfig fastJsonConfig = new FastJsonConfig();
        //todo   这里进行配置，空和null，不返回
        fastJsonConfig.setSerializerFeatures(SerializerFeature.PrettyFormat);
        SerializeConfig serializeConfig = SerializeConfig.globalInstance;
        serializeConfig.put(LocalDateTime.class, LocalDateTimeSerializer.instance);
        fastJsonConfig.setSerializeConfig(serializeConfig);

        List<MediaType> mediaTypeList = new ArrayList<>();
        mediaTypeList.add(MediaType.APPLICATION_JSON_UTF8);
        mediaTypeList.add(MediaType.APPLICATION_JSON);
        fastJsonHttpMessageConverter.setSupportedMediaTypes(mediaTypeList);
        fastJsonHttpMessageConverter.setFastJsonConfig(fastJsonConfig);
        return fastJsonHttpMessageConverter;
    }
}

配置上这个可以在返回的信息中，假如说有null字段的时候，前端不会进行显示这种信息