kafka-streams-KeyValueMapper.adoc

KeyValueMapper

KeyValueMapper is the contract of key-value mappers that map a record to a new value.

KeyValueMapper is the input argument of the following operators:

• KStream.selectKey

• KStream.map

• KStream.flatMap

• KStream.groupBy

• KStream.join

• KStream.leftJoin

• KTable.toStream

• KTable.groupBy

• Printed.withKeyValueMapper

package org.apache.kafka.streams.kstream;

interface KeyValueMapper<K, V, VR> {
  VR apply(final K key, final V value);
}

Table 1. KeyValueMapper Contract

Method	Description
apply	Used when…​FIXME