Build RESTFUL APIs using Kotlin and Spring Boot

A complete hands on approach to learn the Kotlin programming language and build Restful APIs using SpringBoot & Kotlin.

What you'll learn
Kotlin Programming Language and its benefits
Write Code using Kotlin Programming Language
Building Applications using Kotlin
Build RestFul Services using SpringBoot and Kotlin
Test Kotlin using JUnit5
Kotlin and Java Interoperability
Integrate Spring Data JPA with Kotlin
Integration testing DB Layer using TestContainers & JUnit5
Unit Testing Functions calls using Mockk Library

Requirements
Java 11 or Higher is Required
Experience working with any IDE( Intellij, Eclipse)
Experience working with Java
Experience building application using SpringBoot
Gradle or Maven Build tool Experience is must

Description
Kotlin is the Modern, concise and safe programming language and is one of the popular JVM language in this day and age.

It’s also interoperable with Java and other languages, and provides many ways to reuse code between multiple platforms for productive programming.

This course will focus on using Kotlin for Server-Side Development using SpringBoot framework. This is a pure hands-on oriented course which covers these two topics

Covers Kotlin Fundamentals thats necessary for Java Developers

Build RestFul APIs using SpringBoot and Kotlin

Section 1: Getting Started With the Course

This section covers the course objectives and the prerequisites that are needed to make the most out of this course.

Section 2: Getting Started with Kotlin Programming Language

In this section, I will introduce you to Kotlin Programming Language and why its a powerful language for enterprise development.

Introduction to Kotlin

How Kotlin Works with the JVM?

Section 3: Kotlin Fundamentals

In this section, we will explore the fundamentals of Kotlin.

val & var variables in Kotlin

Basic Types - Int, Long, Double, String

Conditionals - If and when block

Ranges , Loops

while & do-While

break, labels and return

Section 4: Functions in Kotlin

In this section, we will learn about functions in Kotlin and different ways of declaring and using them

Defining and Invoking Functions

Default Value Parameters & Named Arguments

Top-Level Functions and Top-level Properties

Section 5: Classes, Interfaces and Inheritance

In this section, we will learn about classes, inheritance and interfaces in detail.

Introduction to class - Creating a class and objects

Primary Constructors

Secondary Constructors

initializer code using init block

Data Classes

Custom Getters and Setters

Inheritance - Extending Classes

Inheritance - Override Functions, Variables

object keyword for creating instance of the class

companion object Keyword

Interfaces

Interfaces - Handling Conflicting Functions

Interfaces - Defining and Overrding Variables

Visibility Modifiers

Type Checking, Casting and Smart Cast

Enum class

Section 6: Nulls in Kotlin

In this section, we will learn about handling nulls in Kotlin

Nullable & Non-Nullable types in Kotlin

Safe Call(?) , Elvis Operator(?:) & Non Null Assertion(!!) to deal with Null Values

Invoking or assigning a Nullable Type to a Non-Nullable Type

Section 7: Collections, Arrays & Lamda Expressions

In this section, I will introduce you to collections, arrays and lambda expressions in Kotlin

Introduction to Collections

Introduction to Lamda Expressions

Lambdas and Higher Order Functions

Filter Operations on Kotlin Collections

Map Operations on Kotlin Collections

FlatMap Operations in Collections

Working With HashMaps

Lazy Evaluation of Collections using Sequences

Nullability in Collections

Section 8 : Exceptions In Kotlin

In this section, I will cover the exceptions in kotlin and the techniques to handle them.

Handling Exceptions using try-catch

Section 9 : Scope Functions

In this section, I will introduce you all to scope functions in Kotlin and its usage.

Introduction to Scope Functions

apply & also Scope Function

let Scope Function

with & run Scope Function

Section 10 : Getting Started with Kotlin and Spring Boot

In this section, I will explain the overview of the app we are going to build and build a very simple API.

Overview of the app & Project Setup

Build a Simple Endpoint - Greeting Controller

Constructor Injection in Spring

Setting up different profiles in Spring Boot

Set up Logging in Kotlin

Section 11 : Integration/Unit Testing using Junit 5

In this section, I will code and explain about the techniques to write different types of test cases using spring boot and Kotlin.

Introduction to Automated Tests & Setting up JUnit5

Integration Test for Controller

Unit Test for Controller - Using the Mockk Mocking library

Section 12 : Build the Course Catalog Service

In this section, we will build the Course Catalog Service to manage the Courses

Set up the Course Entity & CourseDTO

Create CourseRepository & Configure JPA in application.yml file

Build the POST Endpoint for adding new Course I

ntegration test for the POST endpoint using JUnit5

Build the Get Endpoint to retrieve all Courses

Integration test for the GET endpoint to retrieve all the courses

Build the Update Endpoint to update a Course

Integration test for the PUT endpoint using JUnit5

Build the DELETE endpoint to delete a Course

Section 13: Unit Testing Controller layer (Web Tier)

In this section, we will code and learn about how to write unit tests for the controller

Setting up the Unit Test for the CourseController

Unit test for the Post Endpoint in CourseController

Unit test for the GET Endpoint in CourseController

Unit test for the PUT Endpoint in CourseController

Unit test for the DELETE Endpoint in CourseController

Section 14 : Bean Validation using Validators and ControllerAdvice

In this section, we will code and learn the different techniques to apply bean validations and handle exceptions using the ControllerAdvice Pattern

Name and Category as Mandatory using @NotBlank Annotation

Implement Custom Error Handling using ControllerAdvice pattern

Handle Global RuntimeException using ControllerAdvice Pattern

Section 15 : Custom JPA queries using Spring Data JPA and DB Layer testing using @DataJpaTest

In this lecture, we will learn about the techniques to write custom JPA queries and the techniques to test the DB layer using the DataJpaTest

Retrieve Courses By Name using JPA Query Creation Function

Retrieve Courses By Name using Native SQL query

Testing Mutliple sets of Data using @Parameterized test

Section 16: GET Endpoint to retrieve Courses By Name using @RequestParam

In this section, we will code and learn about the usage of RequestParam in the controller endpoint.

Use existing GET endpoint to retrieve Courses by Name

Write Integration test to retrieve course by Name

Section 17 : Entity RelationShips using Spring Data JPA

In this section, I will explain the technique to express the relationships in JPA using Entity and Data classes in Kotlin

Adding Instructor Entity in to the Course Catalog Service

Adding the relationship in the Entity Class

Instructor Controller to Manage Instructor Data

Update CourseService to validate Instructor Data

Fix the CourseController Integration Tests

Fix the CourseController Unit Tests

Section 18 : Integrating with Postgres DB

In this section, we will code and learn to integrate the postgres DB in to the course catalog service.

Setting up the Postgres DB and App to interact with Postgres

Test the app with Postgres DB

Section 19 : Integration Testing using TestContainers

In this section, we will code and learn to integrate the testcontainers to run integration test.

Setting Up TestContainers for the Integration Test

Configure @DataJpaTest with TestContainers

Section 20 : Java & Kotlin Interoperability

In this section, we will code and learn about the interoperability between Java and Kotlin.

Invoking Kotlin Code from Java Class

Invoking Java Code from Kotlin

Useful JVM annotations in Kotlin

By the end of this course, you will be comfortable writing code using the Koltin Programming language and Build RestFuL APIs using SpringBoot and Kotlin.

Who this course is for
Developers who are interested in learning Kotlin Programming language
Developers who are interested in building applications using Kotlin and SpringBoot
Java developers who would like to learn Kotlin Programming Language