Build RESTFUL APIs using Kotlin and Spring Boot

• 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.