java - Spring Boot - 未找到所需的 bean - 但接口(interface)是在同一个类中定义的

Question

当尝试在运行时运行以下示例 spring boot 代码时，我收到错误

Parameter 0 of method runner in springbootdemo.SpringbootDemoApplication required a bean of type 'springbootdemo.SpringbootDemoApplication$ReservationRepository' that could not be found.

这是我的示例代码:

@SpringBootApplication                                                                                                  
public class SpringbootDemoApplication {                                                                                

public static void main(String[] args) {                                                                            
        SpringApplication.run(SpringbootDemoApplication.class, args);                                                   
    }                                                                                                                   

    @Bean                                                                                                               
    CommandLineRunner runner(ReservationRepository rr) {                                                                
        return strings -> {                                                                                             
            Arrays.asList("Les, Josh, Phil, Sasha, Peter".split(","))                                                   
            .forEach(n -> rr.save(new Reservation(n)));                                                                 

            rr.findAll().forEach(System.out::println);                                                                  
            rr.findByReservationName("Les").forEach(System.out::println);                                               
        };                                                                                                              
    }                                                                                                                   


    interface ReservationRepository extends JpaRepository<Reservation, Long> {                                          

        // select * from reservation where reservation_name = :rn                                                       
        Collection<Reservation> findByReservationName(String rn);                                                       
    }                                                                                                                   

    @Entity                                                                                                             
    class Reservation {                                                                                                 

        @Id                                                                                                             
        @GeneratedValue                                                                                                 
        private Long id;                                                                                                

        private String reservationName;                                                                                 

        public Reservation() {      // for JPA - god sake why :-(                                                       
        }                                                                                                               

        public Reservation(String reservationName) {                                                                    
            this.reservationName = reservationName;                                                                     
        }                                                                                                               

        @Override                                                                                                       
        public String toString() {                                                                                      
            return "Reservations{" +                                                                                    
                    "id=" + id +                                                                                        
                    ", reservationName='" + reservationName + '\'' +                                                    
                    '}';                                                                                                
        }                                                                                                               

        public Long getId() {                                                                                           
            return id;                                                                                                  
        }                                                                                                               

        public void setId(Long id) {                                                                                    
            this.id = id;                                                                                               
        }                                                                                                               
    }                                                                                                                   
}    

由于界面存在，我无法弄清楚是什么导致了该问题，不是吗？

我正在使用来自 start.spring.io 的新启动器来发布 1.4.7.RELEASE

Answer 1

默认情况下，Spring 不解析内部存储库，因此您需要显式启用此功能。
只需在您的配置类(或应用程序启动类，它也是您的案例的配置)上使用 @EnableJpaRepositories 以及标志 considerNestedRepositories = true 即可。

@SpringBootApplication      
@EnableJpaRepositories(considerNestedRepositories = true)                                                                                            
public class SpringbootDemoApplication

EnableJpaRepository文档。