我有一个简单的案例课

case class KafkaContainer(key: String, payload: AnyRef)

然后我想通过制作人把这个发给Kafka，我做这个

val byteArrayStream = new ByteArrayOutputStream()
      val output = AvroOutputStream.binary[KafkaContainer](byteArrayStream)
      output.write(msg)
      output.close()
      val bytes = byteArrayStream.toByteArray
      producer.send(new ProducerRecord("my_topic", msg.key, bytes))

这很有效
然后我试着吃这个

Consumer.committableSource(consumerSettings, Subscriptions.topics("my_topic"))
    .map { msg =>
      val in: ByteArrayInputStream = new ByteArrayInputStream(msg.record.value())
      val input: AvroBinaryInputStream[KafkaContainer] = AvroInputStream.binary[KafkaContainer](in)
      val result: Option[KafkaContainer] = input.iterator.toSeq.headOption
      input.close()
        ...
    }.runWith(Sink.ignore)

这对于负载中的任何类都很有效。
但是！如果有任何问题。消费者代码失败
错误：（38，96）找不到com.sksamuel.avro4s.fromrecord[test.messages.kafkancontainer]val输入类型的证据参数的隐式值：avrobinaryinputstream[kafkancontainer]=avroinputstream.BinaryKafkanContainer
错误：（38，96）方法二进制的参数不足：（隐式证据$21:com.sksamuel.avro4s.schemafor[test.messages.kafkacontainer]，隐式证据$22:com.sksamuel.avro4s.fromrecord[test.messages.kafkacontainer]）com.sksamuel.avro4s.avrobinaryinputstream[test.messages.kafkacontainer]。未指定值参数证据$22。val输入：avrobinaryinputstream[kafkacontainer]=avroinputstream.binarykafkacontainer
如果我宣布它与

implicit val schemaFor: SchemaFor[KafkaContainer] = SchemaFor[KafkaContainer]
implicit val fromRecord: FromRecord[KafkaContainer] = FromRecord[KafkaContainer]

它无法用
错误：（58，71）找不到com.sksamuel.avro4s.fromvalue[object]implicit val fromrecord类型的惰性隐式值：fromrecord[kafkacontainer]=fromrecord[kafkacontainer]
错误：（58，71）lazyconverter方法的参数不足：（implicit-fromvalue:shapess.lazy[com.sksamuel.avro4s.fromvalue[object]]）shapess.lazy[com.sksamuel.avro4s.fromvalue[object]]。未指定的值参数fromvalue。隐式val fromrecord:fromrecord[KafkanContainer]=fromrecord[KafkanContainer]
如果添加每个隐式编译器

lazy implicit val fromValue: FromValue[Object] = FromValue[Object]
implicit val fromRecordObject: FromRecord[Object] = FromRecord[Object]
implicit val schemaFor: SchemaFor[KafkaContainer] = SchemaFor[KafkaContainer]
implicit val fromRecord: FromRecord[KafkaContainer] = FromRecord[KafkaContainer]

编译失败并出错
错误：（58，69）宏扩展期间出现异常：java.lang.illegalargumentexception:需求失败：需要case类，但对象不在scala.predef$.require（predef）中。scala:277)在com.sksamuel.avro4s.fromrecord$.applyimpl（fromrecord。scala:283)隐式val fromrecordobject:fromrecord[object]=fromrecord[object]
但是如果我为某个类替换anyref-不需要隐式的，那么一切又正常了