Building a Kafka consumer with Akka

In this recipe, a Kafka consumer is built with Akka.

Getting ready

The Akka connector is available at Maven Central for Scala 2.11 at the following Maven coordinates:

libraryDependencies += "com.typesafe.akka" %% "akka-stream-kafka" % "0.11-M4"

How to do it...

When creating a consumer stream, specify the ProducerSettings defining the following:

• Kafka cluster bootstrap server
• Serializers for the keys and values
• Tuning parameters

The imports necessary for ConsumerSettings are as follows:

import akka.kafka._ 
import akka.kafka.scaladsl._ 
import org.apache.kafka.common.serialization.StringDeserializer 
import org.apache.kafka.common.serialization.ByteArrayDeserializer 
import org.apache.kafka.clients.consumer.ConsumerConfig

To declare and define the ConsumerSettings:

val consumerSettings = ConsumerSettings(system, new ByteArrayDeserializer, new StringDeserializer) 
  .withBootstrapServers("localhost:9092") 
  .withGroupId("group1") 
  .withProperty(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG...