Scala API for Kafka Streams¶

Scala API for Kafka Streams is a separate Kafka Streams module (a Scala library) that acts as a wrapper over the existing Java API for Kafka Streams.

The Scala API for Kafka Streams defines Scala-friendly types that wrap the corresponding Kafka Streams types and simply delegate all method calls to the underlying Java object with the purpose of making it much more expressive, with less boilerplate and more succinct.

scala Package¶

The Scala API is available in the org.apache.kafka.streams.scala package.

import org.apache.kafka.streams.scala._
import org.apache.kafka.streams.scala.kstream._

Library Dependency¶

As a separate Scala library Scala API for Kafka Streams has to be defined as a dependency in a build configuration (e.g. build.sbt).

val kafkaVersion = "3.1.0"
libraryDependencies += "org.apache.kafka" %% "kafka-streams-scala" % kafkaVersion

Implicit Conversions¶

The Scala API for Kafka Streams defines implicit conversions, i.e. Serdes, and ImplicitConversions.

import org.apache.kafka.streams.scala._
import ImplicitConversions._
import serialization.Serdes._

Consumed¶

The Scala API for Kafka Streams comes with Scala objects for creating Consumed, Produced, Materialized and other metadata-related instances with Serdes objects for the key and value types available in implicit scope.

import org.apache.kafka.streams.scala.kstream._