In which cases should you use the @Service annotation in your application?.

The @Service annotation in Spring is used to mark a class as a service layer component that contains business logic. It should be used when implementing components responsible for data processing, executing business operations, and interacting between controllers and repositories.

Using @Service helps:

• Clearly delineate the business logic layer.
• Allow Spring to automatically register the class as a bean and manage its lifecycle.
• Improve code readability and structure.

Example:

@Service
public class UserService {
    public User getUserById(Long id) {
        // business logic to get user
    }
}