Scala Reactive Programming

HelloWorld example description

We will dissect each step one by one to understand the basics of Akka Streams components.

1. Create a Akka Streams Source as follows:

      val helloWorldSource = Source.single("Akka Streams Hello World")

Here, we create the Akka Streams Hello World text message as a Source for this application. We can use the Source.single function to create a Source with one element.

The type annotation of the Source.single function is Source[T,NotUsed], where T is the string in our example. So we can also write the preceding code snippet as follows:

      val helloWorldSource:Source[String,NotUsed] =        Source.single("Akka Streams Hello World")

NotUsed is a sealed abstract class and has one case object, as shown here:

 sealed abstract ...