Book Image

Akka Cookbook

By : Vivek Mishra, Héctor Veiga Ortiz
Book Image

Akka Cookbook

By: Vivek Mishra, Héctor Veiga Ortiz

Overview of this book

Akka is an open source toolkit that simplifies the construction of distributed and concurrent applications on the JVM. This book will teach you how to develop reactive applications in Scala using the Akka framework. This book will show you how to build concurrent, scalable, and reactive applications in Akka. You will see how to create high performance applications, extend applications, build microservices with Lagom, and more. We will explore Akka's actor model and show you how to incorporate concurrency into your applications. The book puts a special emphasis on performance improvement and how to make an application available for users. We also make a special mention of message routing and construction. By the end of this book, you will be able to create a high-performing Scala application using the Akka framework.
Table of Contents (18 chapters)
Title Page
About the Authors
About the Reviewer
Customer Feedback

Overriding the life cycle hooks of an actor

Since we are talking about supervision and monitoring of actors, you should understand the life cycle hooks of an actor. In this recipe, you will learn how to override the life cycle hooks of an actor when it starts, stops, prestarts, and postrestarts.

How to do it...

  1. Create a file called ActorLifeCycle.scala in package com.packt.chapter2.
  2. Add the following imports to the top of the file:
        import akka.util.Timeout 
        import scala.concurrent.Await 
        import scala.concurrent.duration._ 
        import akka.pattern.ask 
  1. Create the following messages to be sent to the actors:
        case object Error  
        case class StopActor(actorRef: ActorRef) 
  1. Create an actor as follows, and override the life cycle methods:
        class LifeCycleActor extends Actor { 
          var sum = 1 
          override def preRestart(reason: Throwable, message: