Book Image

Learning Scala Programming

By : Vikash Sharma
Book Image

Learning Scala Programming

By: Vikash Sharma

Overview of this book

Scala is a general-purpose programming language that supports both functional and object-oriented programming paradigms. Due to its concise design and versatility, Scala's applications have been extended to a wide variety of fields such as data science and cluster computing. You will learn to write highly scalable, concurrent, and testable programs to meet everyday software requirements. We will begin by understanding the language basics, syntax, core data types, literals, variables, and more. From here you will be introduced to data structures with Scala and you will learn to work with higher-order functions. Scala's powerful collections framework will help you get the best out of immutable data structures and utilize them effectively. You will then be introduced to concepts such as pattern matching, case classes, and functional programming features. From here, you will learn to work with Scala's object-oriented features. Going forward, you will learn about asynchronous and reactive programming with Scala, where you will be introduced to the Akka framework. Finally, you will learn the interoperability of Scala and Java. After reading this book, you'll be well versed with this language and its features, and you will be able to write scalable, concurrent, and reactive programs in Scala.
Table of Contents (21 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Writing our first Actor


Writing an Actor is as simple as writing a class that extends the akka.actor.Actor class. And we know that Actors respond to messages, so to identify messages, we have a method named receive that we have to define for each Actor we write. Let's write our SimpleActor:

 

import akka.actor.Actor 
 
class SimpleActor extends Actor { 
    
  override def receive = Actor.emptyBehavior 
 
} 

So, we wrote the SimpleActor with some empty behavior defined in the receive method. But here we've just wrote our Actor; we have to instantiate the Actor as part of an Actor system. After instantiating, we might also want to run our application to see the behavior, hence, let's write the entry point to our application and instantiate an Actor system:

 

import akka.actor.ActorSystem 
 
object AkkaStarter extends App { 
 
  val simpleActorSystem = ActorSystem("SimpleActorSystem") 
 
} 

This statement gives us an instance for an Actor system with the name SimpleActorSystem. Now, we want to create...