Java: Hibernate @OneToOne mapping

Question

I'm trying to get Hibernate @OneToOne annotations working and not having much success here...

Let's say I've got a table called status that looks like this:

+------------------------------------------------+
|                     status                     |
+------------------------------------------------+
| id | frn_user_id | frn_content_id |   status   |
+----+-------------+----------------+------------+
|  1 |     111     |        0       |  "active"  |
+----+-------------+----------------+------------+
|  2 |      0      |       222      | "inactive" |
+----+-------------+----------------+------------+

And I've got an entity for User that looks like this:

@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id", nullable = false)
    private Integer id;

    @OneToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "userId")
    private Status status;

    // getters and setters
}

And a similar one for Content, and another entity for Status that looks like this:

@Entity
@Table(name = "status")
public class Status {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id", nullable = false)
    private Integer id;

    @Column(name = "frn_user_id")
    private Integer userId;

    @Column(name = "frn_content_id")
    private Integer contentId;

    @Column(name = "status")
    private String status;

    // getters and setters
}

When I perform a read on User, I expect that User.getStatus() will return a Status object with id=1. Instead, I get an AnnotationException: "Referenced property not a (One|Many)ToOne: Status.userId in mappedBy User.status"

I've poured through docs, tutorials and examples here on SO, but everything I've tried so far has failed.

Also worth noting: This should support a one-to-zero-or-one relationship, as some user and content records will not have a reference in the status table.

Any help would be greatly appreciated!

Answer 1

Your Status entity must not have properties userId and contentId of type Integer, mapped with @Column. It must have properties user and content of type User and Content, mapped with @OneToOne:

public class User {
    @OneToOne(mappedBy = "user")
    private Status status;
    // ...
}

public class Status {
    @OneToOne
    @JoinColumn(name = "frn_user_id")
    private User user;
    // ...
}

A user has one status. A status has one user.