Build Spring Boot Apps with the Kotlin Programming Language

Learn how to build high-quality Spring Boot applications with the Kotlin programming language.

1. Introduction

• Introduction
• What is Kotlin?
• Installing IntelliJ
• Configuring IntelliJ

2. Working with Strings

• Creating a new Kotlin project
• Variable declaration syntax
• Inferring variable types and println
• Using string templates
• Multiple line strings

3. Other Variable Types

• Using the Double type and determining class types
• The Int data type
• Other data types
• Casting in Java
• Casting in Kotlin
• Chapter review

4. Nullable Variables

• Creating variables that can contain a null value
• Methods that work with nullable parameters
• The null-safe and non-null asserted operators
• The Nothing object type

5. Functions

• The function syntax and the Unit object
• Creating and calling top-level functions
• Single expression functions
• Using named parameters and optional parameters
• Other aspects of functions in Kotlin

6. Classes

• Project structure and packages
• The class declaration and class-level attributes
• Instantiating a class and accessing class-level attributes
• Creating a simple constructor
• Secondary constructors
• Alternative class design
• Overriding getters and setters
• Functions within a class
• Static functions
• Data classes

7. Practical Exercise 1

• Explaining the challenge
• Solution walk-through

8. If and Object Equality

• The if keyword as an expression
• Using if to do a null-safe check
• The let function
• Object equality and the when expression

9. Ranges and Looping

• The while loop
• Using for to loop through a collection
• Destructuring with a for loop
• Looping with a range

10. Collections

• Mutable collections with immutable variables
• Immutable lists
• Mutable lists
• Maps and sets
• Working with arrays

11. Practical Exercise 2

• Explaining the challenge
• Solution walk-through

12. Exceptions and the try-catch Block

• Exceptions are unchecked
• Throwing exceptions
• try as an expression
• use as an expression (try with resources)

13. Testing

• Using JUnit with Kotlin
• The Kotlin test assertions
• Testing for exceptions

14. Polymorphism and Inheritance

• Creating and implementing interfaces
• Class inheritance
• Creating custom exceptions
• Extension functions

15. Java Interoperability

• Instantiating classes and providing values to non-nullable variables
• Using data classes
• Using immutable lists
• Exception handling
• Using static functions
• Importing a Kotlin JAR file into a Java project

16. Getting Started with Spring Boot

• Creating a project with the Spring Initializr
• A hello world controller
• Auto-restarting an application
• Overview of the case study
• Creating views and backing beans
• Connecting views to controller functions
• Adding services
• Posting to a controller
• Dependency injection
• Revisiting backing beans

17. Functional Programming

• Functional programming overview
• Methods that take function parameters—the Java way
• Methods that take function parameters—the Kotlin way
• Functional programming with lists
• filter and flatMap
• reduce and fold
• Working with maps

18. Getting Started with Hibernate

• Adding the Hibernate dependencies
• The challenge of creating entities
• Persisting data to a database

19. Practical Exercise 3

• Step 1: Explaining the challenge
• Solution walk-through
• Mappings between entities
• Upgrading the view
• Step 2: Explaining the challenge
• Solution walk-through
• Step 3: Explaining the challenge
• Solution walk-through

20. Reflection

• The concept of reflection
• Inspecting properties and functions
• A practical use for reflection
• Thank you and goodbye