Dependency Injection (DI) is a core concept in Spring that simplifies object creation and management. It allows you to decouple components by injecting dependencies rather than hardcoding them. Here's a quick guide:

📌 Core Concepts

  • Inversion of Control (IoC): Spring manages object lifecycles and dependencies.
  • Setter/Constructor Injection: Two primary methods to inject dependencies.
  • Autowired Annotation: Simplifies dependency injection in Spring beans.

🧠 Why Use DI?

  • ✅ Promotes loose coupling
  • ✅ Easier testing with mock objects
  • ✅ Centralized configuration management

📂 Example Code

@Service
public class VideoService {
    private final VideoRepository repository;
    
    // Constructor injection
    public VideoService(VideoRepository repository) {
        this.repository = repository;
    }
    
    public List<Video> getTutorials() {
        return repository.findAllByType("tutorial");
    }
}

📌 Related Tutorials

Spring_Framework_Dependency_Injection