Let's say we want to read and parse a CSV file containing Key value pairs. We will be using Alpakka's CSVParser for this. A snippet of a file (src/main/resources/CountryNicCurrencyKeyValueMap.csv) that shows mapping from Country NIC code to currency code with pipe (|) as field delimiter: AD|EUR AE|AED AF|AFN AG|XCD AI|XCD AL|ALL AM|AMD AN|ANG AO|AOA AQ|AQD AR|ARS AS|EUR AT|EUR AU|AUD AW|ANG AX|EUR AZ|AZN BA|BAM BB|BBD BD|BDT BE|EUR BF|XOF BG|BGN BH|BHD BI|BIF BJ|XOF BL|EUR BM|BMD BN|BND BO|BOB BR|BRL BS|BSD BT|INR Following is the code: import java.io.File import java.nio.charset.StandardCharsets import akka.actor.ActorSystem import akka.stream._ import akka.stream.alpakka.csv.scaladsl.CsvParsing import akka.stream.scaladsl.{FileIO, Flow, Sink} import akka.util.ByteString import scala.collection.immutable import scala.concurrent.{ExecutionContext, _} import scala.concurrent.duration._ implicit val system: ActorSystem = ActorSystem("TestApplication") implicit ...