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)

Extend HelloWorld Example With DI

In the previous example, we have developed our first Play Framework HelloWorld Web Application.

For a clear separation between the Play Web Application with DI and without DI, I'll create a new project with the same content without changing the previous project:

  1. Create a Play Framework SBT Project from your favorite IDE (I am using IntelliJ IDEA):
Project Name: play-scala-helloworld-di-app 
  1. Copy the complete content of play-scala-helloworld-app into this project.
  2. Create a HelloWorld Play Controller with DI:


package controllers 
import javax.inject._ 
import play.api.mvc._ 
class HelloWorldDIController @Inject() extends Controller { 
  def helloWorld = Action { 
    Ok(views.html.helloWorld("Hello World With DI.")) 
We will use the same Play View Template for both HelloWorld Controllers...