java - Spring boot @Autowired 无法初始化类

Question

我有以下类(class):-

@SpringBootApplication
@ComponentScan("com.ma.demospringboot")
public class DemoSpringBootApp {
   public static void main(String[] args) {
      SpringApplication.run(DemoSpringBootApp.class, args);
   }
}

我有以下类(class):-

@Service
public class TopicService {
    // if I comment out following autowired, then it is ok.
    @Autowired
    private TopicRepository topicRepository; 
}

我有以下界面:-

public interface TopicRepository extends  CrudRepository<Topic, String> {
}

我有以下类(class):-

@Entity 
public class Topic {
    @Id
    private String id;
    private String name;
    private String description;

    public Topic() {
    }
}

尝试执行时出现以下错误:-

<小时/>

应用程序无法启动

<小时/>

描述:

Field topicRepository in com.ma.demospringboot.service.TopicService required a bean of type 'com.ma.demospringboot.repository.TopicRepository' that could not be found.

行动:

Consider defining a bean of type 'com.ma.demospringboot.repository.TopicRepository' in your configuration.

Answer 1

Spring 容器在扫描期间未找到您的存储库类，添加 @EnableJpaRepositories 以显式指定存储库类所在的包，如下所示:

  @SpringBootApplication
  @ComponentScan("com.ma.demospringboot")
  @EnableJpaRepositories("com.ma.demospringboot.repository")
  @EntityScan(basePackages = "com.ma.demospringboot.domain")
  public class DemoSpringBootApp {
      //your current code here
  }

更新1:

Not a managed type: class com.ma.demospringboot.domain.Topic

现在，您的Topic实体类未找到，因此您需要@EntityScan(basePackages = "com.ma.demospringboot.domain")来扫描实体类(如上所示)。

更新2:

I did exactly as you suggested, but NOT working

您打包类的方式存在问题，请仔细检查，并确保服务器已编译/构建和使用最新的类。