Dependency injection fails when using a library with its own application context

Question

I have some issues with DI in Spring Framework (version 4.1.1). I wrote a small library that creates its own application context and uses DI to configure its components. It consists of the following classes. First the config file for the application context.

@Configuration
@ComponentScan(basePackages = { "package.containing.services" })
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = {"package.containing.repositories"})
@PropertySource({"classpath:config-file.properties"})
public class ConnectorConfig {
    @Resource
    private Environment env;

    @Bean
    public DataSource dataSource() { /* DataSource config here */ }

    @Bean
    public EntityManagerFactory entityManagerFactory() { /* EntityManagerFactory config here */ }

    @Bean
    public PlatformTransactionManager transactionManager() { /* TransactionManager config here */ }
}

The JPA Repository:

@Repository
@Transactional(readOnly = true)
public interface LogEntryJpaRepository extends JpaRepository<LogEntryEntity, Long> {
    @Query("SELECT l FROM LogEntryEntity l WHERE logentry_time >= :fromDate AND logentry_time <= :toDate AND logentry_data NOT LIKE 'EXTERNAL COMMAND:%' ORDER BY logentry_time ASC, logentry_id ASC")
    public List<LogEntryEntity> findInTimeframe(@Param("fromDate") Timestamp fromDate, @Param("toDate") Timestamp toDate);


    @Query("SELECT COUNT(l) FROM LogEntryEntity l WHERE logentry_time >= :fromDate AND logentry_time <= :toDate AND logentry_data NOT LIKE 'EXTERNAL COMMAND:%'")
    public long countInTimeframe(@Param("fromDate") Timestamp fromDate, @Param("toDate") Timestamp toDate);
}

A simple service that forwards calls to the repository:

@Service
public class Connector {
    @Autowired
    private LogEntryJpaRepository logEntryRepo;

    public LogEntryEntity getLogEntryById(long id) {
        return logEntryRepo.findOne(id);
    }

    public List<LogEntryEntity> getLogEntriesInTimeframe(LocalDateTime fromDate, LocalDateTime toDate) {
        return logEntryRepo.findInTimeframe(Timestamp.valueOf(fromDate), Timestamp.valueOf(toDate));
    }

    public long countLogEntriesInTimeframe(LocalDateTime fromDate, LocalDateTime toDate) {
        return logEntryRepo.countInTimeframe(Timestamp.valueOf(fromDate), Timestamp.valueOf(toDate));
    }
}

And finally a factory that provides the singleton instance of the service to external consumers:

public class ConnectorFactory {
    private static ApplicationContext ctx;

    public static Connector getInstance() {
        if(ctx == null) {
            ctx = new AnnotationConfigApplicationContext(ConnectorConfig.class);
        }

        return ctx.getBean(Connector.class);
    }

    private ConnectorFactory() {};
}

I wrote some unit tests to test the factory and repository and it is all working fine. I get a bean returned from the factory.

But when I include this library in a larger project the DI does no longer work properly. The larger project consists of several services that consume connectors like the above to fetch data from external services. They are injected using the @Autowired annotation It is a maven project so I added the above library to the dependencies, compiling works fine. I added a bean definition to a config class in my larger project to gain access to the connector's service:

@Configuration
@EnableTransactionManagement(proxyTargetClass = true)
@ComponentScan({"de.decoit.imonitor.gui.dao"})
@PropertySource({"classpath:imonitor-gui.properties"})
public class PersistenceConfig {
    @Resource
    private Environment env;

    @Bean
    public Connector connector() {
        return ConnectorFactory.getInstance();
    }
}

And this is where the problem occurs: When injecting the Connector bean into a service in my larger project, the DI inside the library fails. It says that he cannot find a suitable bean for the LogEntryJpaRepository dependency.

Why does the DI work fine when run inside a unit test but does fail when used inside another application context? In my understanding the context of the larger project does not need to know the repository bean, the configuration is done by the context inside the library. That context just exposes the service bean to external consumers, no configuration needs to be done by the context of the larger project.

Is there some mistake in my configuration or even design flaws for the library itself? This is my first library that uses DI to configure itself so maybe I just did something completely wrong?

[EDIT] Removed @Import statement from configuration class, that was a remains of testing, not there in real code. Sorry!