Hibernate：在Spring中保存复杂的数据模型

Question

My data model has a network of entities. A set of entities that reference each other with @OneToOne , @ManyToOne , etc. Some of these references are defined to be @NotNull

@Entity
@Table(name="UserDetails")
public class CustomUserDetails implements Serializable {
    @NotNull
    @JoinColumn(name="user_id", referencedColumnName="id")
    @OneToOne(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
    private User user;
    //.....
}

CustomUserDetailsService handles saving and loading instances of CustomUserDetails class from the DB and UserDetailsRepository is an interface that extends CrudRepisitory .

When user makes a call to /signup we want to create and save an instance of CustomUserDetails to the db. But before server persists a new instance of CustomUserDetails , it has to create a new instance of type User and save it to the db (as it is defined as @NotNull ).

Does it makes sense to do this in CustomUserDetailsService , in the Controller? or where else ?

I'm afraid that the design gets too complex and there would be lots of cross references between service classes of different entities when the data model gets more complicated.

Answer 1

Following the same style, you should have a class called something like "UserService" , that handles CRUD operations for users. Class CustomUserDetailsService should hold a member that is UserService , preferably using @Autowire annotation.

Before creating a new custom user details, call the UserService to create a new user (if needed).

In principle it could end here, CustomUserDetailsService is familiar with UserService , but vice versa. You have defined cascade=CascadeType.ALL , so if you delete a user, the customer user details are also deleted.

Just make sure that other relations the CustomUserDetails have their cascade defined correctly.