Kotlin is a statically typed Java Virtual Machine (JVM) language, enabling code that is expressive, short, and readable. Kotlin is created by JetBrains, the team behind the IntelliJ IDE. In the last few years, Kotlin has picked up steam and is now the preferred language for developing Android applications.

Kotlin has a concise syntax and can make developing web applications easier. Recognizing this potential, the Spring Frameworks provided support for Kotlin, starting from version 5.0.

In this chapter, we will explore some of the important features of Kotlin and learn how to create a basic REST service with Kotlin and Spring Boot.

By the end of this chapter, you will understand the following:

• What is Kotlin?
• How does Kotlin compare with Java?
• How to create a Kotlin project in Eclipse
• How to create a Spring Boot project with Kotlin
• How to implement and unit test a simple Spring Boot REST service using Kotlin