使用Spring-JPA的单向多人映射

在我的项目中,我希望有许多单向映射。为此,我创建了用户和配方实体以及它们的存储库(使用Spring JPA存储库)。现在我想用一些示例条目填充我的数据库。启动spring boot应用程序后,将发生错误:

org.hibernate.PersistentObjectException:传递给的分离实体 持久化:com.example.demo.database.Recipe

以下是我的用户和配方类:

--用户--

@Data
@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NotNull
    private String email;

    @NotNull
    @Size(min = 8)
    private String password;

    @ManyToMany(cascade = CascadeType.ALL)
    private Set<Recipe> favouriteRecipes = new HashSet<>();

    private User() {}

    public User(String email, String password) {
        this.email = email;
        this.password = password;
    }
}

--配方--

@Data
@Entity
public class Recipe {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NotNull
    private String title;

    private Recipe() {}

    public Recipe(String title) {
        this.title = title;
    }

}

下面是我如何向数据库添加行:

@Component
public class DatabaseInitializer implements CommandLineRunner {

    @Autowired
    private UserRepository userRepository;

    @Override
    public void run(String... args) throws Exception {
        User u1 = new User("rick.astley@gmail.com", "admin123");
        User u2 = new User("john.doe@gmail.com", "admin123");

        Recipe r1 = new Recipe("Chicken curry");
        Recipe r2 = new Recipe("Spaghetti bolognese");

        u1.getFavouriteRecipes().add(r1);
        u1.getFavouriteRecipes().add(r2);

        u2.getFavouriteRecipes().add(r1);
        u2.getFavouriteRecipes().add(r2);

        userRepository.save(u1);
        userRepository.save(u2);

    }
}

我试着跟随 this 教程,但在那里,他使用hibernate而不是Spring存储库,所以这就是我被困在这里的原因。我真的不知道我错在哪里。

任何帮助都将不胜感激:)