Book Image

Scala Reactive Programming

By : Rambabu Posa
Book Image

Scala Reactive Programming

By: Rambabu Posa

Overview of this book

Reactive programming is a scalable, fast way to build applications, and one that helps us write code that is concise, clear, and readable. It can be used for many purposes such as GUIs, robotics, music, and others, and is central to many concurrent systems. This book will be your guide to getting started with Reactive programming in Scala. You will begin with the fundamental concepts of Reactive programming and gradually move on to working with asynchronous data streams. You will then start building an application using Akka Actors and extend it using the Play framework. You will also learn about reactive stream specifications, event sourcing techniques, and different methods to integrate Akka Streams into the Play Framework. This book will also take you one step forward by showing you the advantages of the Lagom framework while working with reactive microservices. You will also learn to scale applications using multi-node clusters and test, secure, and deploy your microservices to the cloud. By the end of the book, you will have gained the knowledge to build robust and distributed systems with Scala and Akka.
Table of Contents (16 chapters)

Akka Streams programming basics

Before we develop some Akka Streams applications in this chapter, we will first take some baby steps to understand the Streams API very well.

Creating a Source

To create an Akka Stream's Source, we need to use one of its functions, such as single, by providing some input elements. For instance, create a Source that contains the numbers 1 to 10 as shown here:

val numbersSource = Source.single(1 to 10) 

If we add this code snippet to a Scala App and run it from your favorite IDE or using the sbt command, we don't see any output. This is because Akka Streams components are executed only when we run them manually:

package com.packt.publishing.akka.streams.hello