Springboot2.0 + Kotlin自定义json序列化不返回null字段的方法

spring:
  jackson:
    default-property-inclusion: non_null

override fun extendMessageConverters(converters: MutableList<HttpMessageConverter<*>>) {
  converters.forEach {
    if (it is MappingJackson2HttpMessageConverter) {
      it.objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL)
    }
  }
}