Mark Tranter created KAFKA-7653: ----------------------------------- Summary: Streams-Scala: Add type level differentiation for Key and Value serdes. Key: KAFKA-7653 URL: https://issues.apache.org/jira/browse/KAFKA-7653 Project: Kafka Issue Type: Improvement Components: streams Reporter: Mark Tranter
Implicit resolution/conversion of Serdes/Consumed etc is a big improvement for the Scala Streams API. However in cases where a user needs to differentiate between Key and Value serializer functionality (i.e. using the Schema Registry), implicit resolution doesn't help and could cause issues. e.g. {code:java} case class MouseClickEvent(pageId: Long, userId: String) builder // Long serde taken from implicit scope configured with // `isKey` = true .stream[Long, MouseClickEvent]("mouse-clicks") .selectKey((_,v) => v.userId) .groupByKey .aggregate(() => 0L, (_: String, mce: MouseClickEvent, count: Long) => count + 1) .toStream // Same Long serde taken from implicit scope configured with // `isKey` = true, even thought the `Long` value in this case // will be the Value .to("mouse-clicks-by-user") {code} It would be ideal if Key and Value Serde/SerdeWrapper types/type classes could be introduced to overcome this limitation. -- This message was sent by Atlassian JIRA (v7.6.3#76005)