Is it mandatory to apply the @Repository annotation in every case when working with repositories?

The @Repository annotation is not always mandatory, but it is recommended to use it for classes responsible for data access (repositories) in Spring.

Main reasons for using @Repository:

• It allows Spring to recognize the class as a component for automatic scanning and dependency injection.
• It provides translation of database-related exceptions into unified Spring exceptions (DataAccessException).

If you are using Spring Data JPA repository interfaces, the @Repository annotation is usually not needed, as Spring automatically handles such interfaces.

In other cases, if you write your own repository implementations, it is advisable to annotate them with @Repository for proper functioning and exception handling.