spring - CommandLineRunner 需要一个无法找到的 bean

Question

总的来说，我对 API 和 Spring 的开发还很陌生。

我正在尝试使用 CommandLineRunner 来填充我的存储库，但它说它找不到我放入参数中的所需 bean。

@SpringBootApplication
public class DemoApplication {

    private static final Logger logger = LoggerFactory.getLogger(DemoApplication.class);

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


    @Bean
    public CommandLineRunner initializeDB(StudentRepository studentRepository){
        return (args)->{
            studentRepository.save(new Student("John1", "Doe1", "asdasda1","Comp Sci1",21));
            studentRepository.save(new Student("John2", "Doe2", "asdasda2","Comp Sci2",22));
            studentRepository.save(new Student("John3", "Doe3", "asdasda3","Comp Sci3",23));
            studentRepository.save(new Student("John4", "Doe4", "asdasda4","Comp Sci4",24));
            studentRepository.save(new Student("John5", "Doe5", "asdasda5","Comp Sci5",25));
            studentRepository.save(new Student("John6", "Doe6", "asdasda6","Comp Sci6",26));
            logger.info("The sample data has been generated");
        };
    }
}

这是我的应用程序类，下面是我的存储库类。

import org.springframework.data.jpa.repository.JpaRepository;

import com.example.model.Student;

public interface StudentRepository extends JpaRepository<Student, Integer> {
}

我缺少什么基本的东西吗？提前致谢

Answer 1

最简单、明智的事情

DemoApplication(或用@SpringBootApplication注释的任何类)应驻留在包结构的根部

这意味着，对于您希望 spring 管理其 bean 生命周期的任何其他类，请将其移至 DemoApplication 的(子)包中。

换句话说，如果您的 DemoApplication 位于 src/main/java/com/yourorg 包中，那么 StudentRepository 应该位于 src/main/java/com/yourorg 的(子)包中