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

Adapter

The main goal of the Adapter design pattern is to convert one interface to another interface. In the physical world, the best example of this idea would be an electrical plug adapter or a USB adapter.

Imagine yourself in a hotel room late in the evening, with 7% battery left on your phone. Your phone charger was left in the office at the other end of the city. You only have an EU plug charger with a Mini USB cable. But your phone uses USB-C, as you had to upgrade. You're in New York, so all of your outlets are (of course) USB-A. So, what do you do? Oh, it's easy. You look for a Mini USB to USB-C adapter in the middle of the night and hope that you have remembered to bring your EU to US plug adapter as well. Only 5% battery left – time is running out!

So, now that we understand what adapters are for in the physical world, let's see how we can apply the same principle in code.

Let's start with interfaces.

USPlug assumes that power is Int...