您可能正在使用ClientRegistrationRepository接口的InMemoryClientRegistrationRepository实现。如果要从另一个位置检索客户端，则必须创建该接口的新实现。如果您使用的是Spring data JPA，则可以执行以下操作：

public interface ClientRegistrationSpringDataRepository extends JpaRepository<ClientRegistrationEntity, String> { 

}

@Repository
public class DaoClientRegistrationRepository implement ClientRegistrationRepository {

    private final ClientRegistrationSpringDataRepository repository;

    // constructor

    @Override
    public ClientRegistration findByRegistrationId(String registrationId) {
        ClientRegistrationEntity entity = this.repository.getById(registrationId);
        return mapToClientRegistration(entity);
    }

    private ClientRegistration mapToClientRegistration(ClientRegistrationEntity entity) {
        // your logic
    }

}