<dependency> <groupId>org.osgi</groupId> <artifactId>org.osgi.annotation</artifactId> <version>1.4.0</version> </dependency> import org.osgi.annotation.versioning.ProviderType; @ProviderType public interface UserService { User getUserById(int id); } import org.osgi.annotation.versioning.ConsumerType; import org.osgi.annotation.versioning.ProviderType; @ConsumerType public interface UserClient { void processUser(User user); } @ProviderType public interface UserService { User getUserById(int id); }