Kafka Producer/Consumer Example in Scala

ConsumerExample.scala

import java.util

import org.apache.kafka.clients.consumer.KafkaConsumer

import scala.collection.JavaConverters._

object ConsumerExample extends App {

  import java.util.Properties

  val TOPIC="test"

  val  props = new Properties()
  props.put("bootstrap.servers", "localhost:9092")

  props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer")
  props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer")
  props.put("group.id", "something")

  val consumer = new KafkaConsumer[String, String](props)

  consumer.subscribe(util.Collections.singletonList(TOPIC))

  while(true){
    val records=consumer.poll(100)
    for (record<-records.asScala){
     println(record)
    }
  }
}

ProducerExample.scala

object ProducerExample extends App {
 
 import java.util.Properties

 import org.apache.kafka.clients.producer._

 val  props = new Properties()
 props.put("bootstrap.servers", "localhost:9092")
  
 props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer")
 props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer")

 val producer = new KafkaProducer[String, String](props)
   
 val TOPIC="test"
 
 for(i<- 1 to 50){
  val record = new ProducerRecord(TOPIC, "key", s"hello $i")
  producer.send(record)
 }
    
 val record = new ProducerRecord(TOPIC, "key", "the end "+new java.util.Date)
 producer.send(record)

 producer.close()
}

A full kafkasteams example here
https://github.com/fancellu/kafkastreams