Spring的@Autowire注释在JpaRepository上返回null

Question

我正在使用spring-data-jpa构建Web应用程序，但现在出现错误：

Exception in thread "main" java.lang.NullPointerException 
    at com.example.test.demo.config.service.RegionServiceImpl.getAll(RegionServiceImpl.java:40)
    at com.example.test.demo.DemoApplication.main(DemoApplication.java:45)

存储库：

import com.example.test.demo.config.entity.Region;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface RegionRepository extends JpaRepository<Region, Integer> {

}

服务：

@Component
public class RegionServiceImpl implements RegionService {

  @Autowired
  private RegionRepository regionRepository;

和型号：

@Entity
//@Table(name = "geo.region")
@Table(name = "region", schema = "geo")
public class Region implements Serializable {


  @Id
  @GeneratedValue
  @Column(name = "id", length = 6, nullable = false)
  private Integer id;
  @Column(name = "title")
  private String title;

  public Region() {
  }

但是现在我在这一步有了NPE：

@Autowired
private RegionRepository regionRepository;

请帮助！ ：（