Spring JPAHibernate：无法导入 bean 定义

xml
    org.springframework.boot
    spring-boot-starter-data-jpa

java
@ComponentScan(basePackages = "com.example")

properties
spring.datasource.url=jdbc:mysql://localhost:3306/mydatabase
spring.datasource.username=root
spring.datasource.password=123456
spring.jpa.database-platform=org.hibernate.dialect.MySQL5Dialect

java
@Entity
@Table(name = "books")
public class Book {
    
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String title;
    
    private String author;
    
    // 省略getter和setter方法
    
}

java
@Repository
public interface BookRepository extends JpaRepository {
    
    List findByAuthor(String author);
    
}

java
@RestController
public class BookController {
    
    @Autowired
    private BookRepository bookRepository;
    
    @GetMapping("/books")
    public List getAllBooks() {
        return bookRepository.findAll();
    }
    
    // 省略其他方法
    
}