Organizing Business Logic with Spring Boot Services

As your web applications grow, stuffing database queries and complex business rules directly into your web controllers leads to fragile, unmaintainable code. To build scalable software, you must learn how to separate concerns and isolate your application's core logic. This text-based course guides you through the process of refactoring Spring Boot applications, demonstrating how to migrate complex operations into a dedicated service layer for cleaner design and better testability. What you'll learn: - Understand the foundational architecture of Spring Boot applications, including controllers, services, and repositories. - Apply the Service Pattern to decouple business rules from HTTP request handling. - Refactor legacy controller code by moving operations like cart management into reusable service components. - Configure modern dependency injection using constructor-based injection instead of field injection. - Practice writing clean, reactive data flows using modern WebFlux patterns. - Design robust data transfer objects using modern Java records to safely pass data between layers. You will start with the fundamental concepts of layered architecture before walking through step-by-step refactoring exercises. Through clear explanations and structured code examples, you will learn to transition from tangled controllers to a modular, testable codebase. This course is designed for beginner Java developers who understand basic Spring Boot but want to learn professional application design patterns. No advanced architectural experience is required. Start reading today to write cleaner, more maintainable Spring Boot applications.