Book Image

Kotlin Design Patterns and Best Practices - Second Edition

By : Alexey Soshin
Book Image

Kotlin Design Patterns and Best Practices - Second Edition

By: Alexey Soshin

Overview of this book

This book shows you how easy it can be to implement traditional design patterns in the modern multi-paradigm Kotlin programming language, and takes you through the new patterns and paradigms that have emerged. This second edition is updated to cover the changes introduced from Kotlin 1.2 up to 1.5 and focuses more on the idiomatic usage of coroutines, which have become a stable language feature. You'll begin by learning about the practical aspects of smarter coding in Kotlin, as well as understanding basic Kotlin syntax and the impact of design patterns on your code. The book also provides an in-depth explanation of the classical design patterns, such as Creational, Structural, and Behavioral families, before moving on to functional programming. You'll go through reactive and concurrent patterns, and finally, get to grips with coroutines and structured concurrency to write performant, extensible, and maintainable code. By the end of this Kotlin book, you'll have explored the latest trends in architecture and design patterns for microservices. You’ll also understand the tradeoffs when choosing between different architectures and make informed decisions.
Table of Contents (17 chapters)
1
Section 1: Classical Patterns
6
Section 2: Reactive and Concurrent Patterns
11
Section 3: Practical Application of Design Patterns

Abstract Factory

Abstract Factory is a greatly misunderstood design pattern. It has a notorious reputation for being very complex and bizarre. Actually, it's quite simple. If you understood the Factory Method design pattern, you'll understand this one in no time. This is because the Abstract Factory design pattern is a factory of factories. That's all there is to it. The factory is a function or class that's able to create other classes. In other words, an abstract factory is a class that wraps multiple factory methods.

You may understand this and still wonder what the use of such a design pattern may be. In the real world, the Abstract Factory design pattern is often used in frameworks and libraries that get their configuration from files. The Spring Framework is just one example of these.

To better understand how the design pattern works, let's assume we have a configuration for our server written in a YAML file:

server: 
    ...