Developing RESTful APIs with Kotlin and Spring Boot Online Course

Developing RESTful APIs with Kotlin and Spring Boot Online Course

Kotlin, a modern, concise, and safe programming language, has emerged as one of the most popular JVM languages. Known for its Java interoperability and cross-platform capabilities, Kotlin enables efficient and productive programming. This course begins with an introduction to its objectives and prerequisites. We then explore Kotlin's strengths for enterprise development and dive into its fundamentals, including val and var variables, basic data types, loops, and more. Advanced topics such as classes, inheritance, interfaces, object keywords, type checking, and smart casting are covered in detail.

Knowledge gained

Further, you’ll learn about collections, arrays, lambda expressions, and the usage of Kotlin's scope functions. The course progresses to integrating Kotlin with Spring Boot, building a course catalog service, managing controller endpoints with @RequestParam, and writing unit tests. Finally, you'll master expressing relationships in JPA using Kotlin's entity and data classes. By the end of the course, you will confidently use Kotlin for coding and build robust RESTful APIs with Spring Boot.

Key Benefits

• Gain expertise in integration testing of the database layer by leveraging TestContainers and JUnit 5, ensuring robust and reliable application behavior.
• Master unit testing of function calls using the mock library, enabling precise validation of isolated components within your application.
• Develop efficient and scalable RESTful services by utilizing the power of Spring Boot and the modern programming features of Kotlin.

Target Audience

This course is designed for developers seeking to learn the Kotlin programming language, those interested in building applications with Kotlin and Spring Boot, and Java developers aiming to expand their expertise by mastering Kotlin. While prior experience with Java is not mandatory, having a foundational understanding of Java will be beneficial for maximizing the learning experience.

Learning Objectives

• Gain a comprehensive understanding of the Kotlin programming language and its advantages for modern development.
• Develop the skills to write clean, efficient, and maintainable code using Kotlin.
• Learn how to design and build robust applications leveraging Kotlin's features.
• Explore Kotlin and Java interoperability, enabling seamless integration into existing Java-based projects.
• Master the integration of Spring Data JPA with Kotlin for efficient database management.
• Acquire proficiency in testing Kotlin applications using JUnit 5, ensuring reliability and code quality.

Course Outline

The Developing RESTful APIs with Kotlin and Spring Boot Exam covers the following topics - 

Module 1. Introduction to Kotlin Programming

• Overview of the Course
• Required Knowledge
• Getting Acquainted with Kotlin
• Kotlin and the Java Virtual Machine (JVM)

Module 2. Core Concepts in Kotlin

• Steps for Setting Up the Development Environment
• Writing Your First Kotlin Program
• Understanding val and var Variables
• Exploring Basic Data Types: Int, Long, Double, String
• Conditional Statements: If and When
• Utilizing Ranges and Loops
• Understand Implementing while and do-While Loops
• Controlling Flow with Break, Labels, and Return

Module 3. Kotlin Functions

• Steps for Creating and Using Functions
• Learn about Parameters with Default Values and Named Arguments
• Working with Top-Level Functions and Properties

Module 4. Object-Oriented Programming in Kotlin

• Defining Classes and Objects
• Understanding Primary Constructors
• Secondary Constructors Explained
• Using the init Block for Initialization
• Working with Data Classes
• Customizing Getters and Setters
• Implementing Inheritance: Extending Classes and Overriding Members
• Utilizing the Object Keyword for Instances
• Using Companion Objects
• Understand Interfaces and Their Usage
• Managing Conflicts in Interface Functions
• Defining and Overriding Interface Variables
• Controlling Access with Visibility Modifiers
• Explore Type Checking, Casting, and Smart Casting
• Introduction to Enum Classes

Module 5. Handling Null Values in Kotlin

• Nullable vs. Non-Nullable Types
• Learn about Managing Nulls with Safe Calls, Elvis Operator, and Non-Null Assertion
• Assigning Nullable Types to Non-Nullable Variables

Module 6. Collections, Arrays, and Lambdas

• Overview of Kotlin Collections
• Understanding Lambda Expressions
• Higher-Order Functions and Lambdas in Action
• Process of Filtering Operations in Collections
• Mapping Data in Collections
• Using FlatMap with Collections
• Manipulating HashMaps
• Lazy Evaluation with Sequences
• Dealing with Nulls in Collections

Module 7. Exception Handling and Scope Functions

• Managing Exceptions with try-catch
• Introduction to Scope Functions
• Using Apply and Also Functions
• Leveraging the Let Function
• Understanding With and Run Functions

Module 8. Kotlin with Spring Boot

• Setting Up the Project and Application Overview
• Creating a Simple Greeting Controller Endpoint
• Constructor Injection in Spring Boot
• Configuring Profiles in Spring Boot
• Logging in Kotlin

Module 9. Testing with JUnit 5

• Automated Testing and JUnit 5 Setup
• Writing Integration Tests for Controllers
• Unit Testing Controllers with Mock Libraries

Module 10. Developing a Course Catalog Service

• Defining the Course Entity and DTO
• Creating a Repository and Configuring JPA
• Implementing the POST Endpoint for Adding Courses
• Writing Integration Tests for POST Endpoints
• Building the GET Endpoint to Retrieve All Courses
• Testing GET Endpoint Integration
• Updating Courses with PUT Endpoint
• Testing PUT Endpoint Integration
• Deleting Courses with DELETE Endpoint

Module 11. Unit Testing the Web Layer

• Setting Up Unit Tests for CourseController
• Writing Unit Tests for POST, GET, PUT, and DELETE Endpoints

Module 12. Validations and Error Handling

• Enforcing Mandatory Fields with @NotBlank
• Custom Error Handling Using ControllerAdvice
• Handling Global Runtime Exceptions with ControllerAdvice

Module 13. Custom Queries and Database Testing

• Fetching Courses by Name Using JPA Queries
• Writing Native SQL Queries for Retrieval
• Testing with Parameterized Data

Module 14. GET Endpoint for Course Retrieval by Name

• Using GET Endpoint with @RequestParam
• Writing Integration Tests for Name-Based Retrieval

Module 15. Modeling Entity Relationships

• Adding Instructor Entities to the Service
• Defining Relationships Between Entities
• Creating a Controller for Instructor Data Management
• Updating Services to Validate Instructor Information
• Fixing Integration and Unit Tests

Module 16. Postgres Database Integration

• Setting Up PostgreSQL with the Application
• Testing Application Functionality with Postgres

Module 17. Integration Testing Using TestContainers

• Configuring TestContainers for Integration Tests
• Using TestContainers with @DataJpaTest

Module 18. Java-Kotlin Interoperability

• Calling Kotlin Code from Java
• Accessing Java Code in Kotlin
• Leveraging Useful JVM Annotations in Kotlin