JPA - Can an @JoinColumn be an @Id as well? SerializationException occurs.
- by Shivago
Hi everyone,
I am trying to use an @JoinColumn as an @Id using JPA and I am getting SerializationExceptions, "Could not serialize."
UserRole.java:
@Entity
@Table(name = "authorities")
public class UserRole implements Serializable {
@Column(name = "authority")
private String role;
@Id
@ManyToOne
@JoinColumn(name = "username")
private User owner;
...
}
User.java:
@Entity
@Table(name = "users")
public class User implements Serializable {
@Id
@GeneratedValue
protected Long id;
@Column(name = "username")
protected String email;
@OneToMany(mappedBy = "owner", fetch = FetchType.LAZY, cascade = CascadeType.ALL)
protected Set<UserRole> roles = new HashSet<UserRole>();
....
}
"username" is set up as a unique index in my Users table but not as the primary key.
Is there any way to make "username" act as the ID for UserRole? I don't want to introduce a numeric key in UserRole. Have I totally lost the plot here?
I am using MySQL and Hibernate under the hood.
