Spring Managed Component

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In Spring Framework, the @Component annotation is used to indicate that a class is a Spring-managed component.
When a class is annotated with @Component, it becomes eligible for auto-detection when using component scanning.
This means that Spring will automatically detect these components and register them as beans in the application
context.

The reason you shouldn't use Service and Repository classes (which are typically annotated with @Service and
@Repository) directly within a class annotated with @Component is primarily due to concerns about tight
coupling, separation of concerns, and adherence to design principles such as SOLID.

Here's a more detailed explanation:

1. Separation of Concerns: The @Service annotation is used for service layer classes that contain business
   logic, while the @Repository annotation is used for data access objects (DAOs) that handle database operations.
   By keeping these concerns separate from components annotated with @Component, you maintain a clear separation
   between different layers of your application.

2. Loose Coupling: Using Service and Repository classes within a class annotated with @Component can
   lead to tight coupling, making it harder to test and maintain the code. It's better to inject these dependencies
   using constructor injection or setter injection, which promotes loose coupling and makes it easier to swap out
   implementations for testing or other purposes.

3. Adherence to Design Principles: The @Service and @Repository annotations help you adhere to design
   principles like Single Responsibility Principle (SRP) and Dependency Inversion Principle (DIP). By annotating
   classes with these specific roles, you make it clear what each class is responsible for, which improves code
   readability and maintainability.

4. Auto-wiring: Spring's dependency injection mechanism allows you to automatically wire dependencies
   annotated with @Service or @Repository into components annotated with @Component. This promotes better
   design practices and makes your application more modular and flexible.

5. Best Practices: Following best practices in software development helps ensure that your code is scalable,
   maintainable, and easier to understand for other developers who might work on the project in the future.

In summary, using Service and Repository classes within a class annotated with @Component goes against the
principles of separation of concerns, loose coupling, and adherence to design patterns. It's better to keep these
concerns separate and use dependency injection to wire them together appropriately.