How does Spring ensure efficient and fast management of component lifecycle and dependencies?

Spring uses an Inversion of Control (IoC) container that manages the lifecycle of components (beans) and their dependencies. When the Spring application starts, it scans configurations and automatically creates bean instances, injecting necessary dependencies via constructors, setters, or fields. This allows centralized management of object creation and destruction, simplifies testing, and enhances code modularity.

Example of a simple bean with dependency injection:

@Component
public class UserService {
    private final UserRepository userRepository;

    @Autowired
    public UserService(UserRepository userRepository) {
        this.userRepository = userRepository;
    }

    // methods
}

Here, Spring will automatically create and inject UserRepository into UserService."}]}]}