Book Image

Akka Cookbook

By : Piyush Mishra, Vivek Mishra, Héctor Veiga Ortiz
Book Image

Akka Cookbook

By: Piyush Mishra, 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

Creating stream sources, flows, and sinks

Now that we are more familiar with the different stages, let's see how we can modularize and reuse them. Akka Streams provides a large number of stages out of the box. We could group them into the following categories:

  • Source stages
  • Sink stages
  • Processing stages
  • Timer-driven stages
  • Back pressure aware stages
  • Nesting and flattening stages
  • Time aware stages
  • Fan-in stages
  • Fan-out stages

In this recipe, we will reuse the code from the previous recipe to demonstrate how to make it modular. We will create two different streams that will use the same immutable stages but will run independently.

Getting ready

We will use the same prerequisites as the previous recipe. This time, we will implement a stream to do a word count. We will consume a GZIP compressed file and count the occurrences of each word.

How to do it...

For this recipe, perform the following steps:

  1. Creating a test file named gzipped-file inside src/main/resources with the following contents: