休眠映射保存问题

Question

I have a two problem entityes fields in my project: First:

public class User implements UserDetails {
    private static final long serialVersionUID = -8442780593066407492L;
    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;

    @ManyToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinTable(name = "user_role",
            joinColumns = {@JoinColumn(name = "user_id")},
            inverseJoinColumns = {@JoinColumn(name = "role_id")})
    private Set<UserRole> userRoles = new HashSet<UserRole>();

    @OneToMany(mappedBy = "user", cascade = CascadeType.REMOVE)
    private Set<CommentReserv> comments = new HashSet<CommentReserv>();

    public Collection<? extends GrantedAuthority> getAuthorities() {
        List<SimpleGrantedAuthority> result = new 
        ArrayList<SimpleGrantedAuthority>();
        for (UserRole userRole: userRoles) {
            result.add(new 
            SimpleGrantedAuthority(userRole.getListRole().name()));
            }
        return result;
    }
...
}

Second:

public class CommentReserv implements Serializable {
    private static final long serialVersionUID = 1579363480188238317L;

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;

    @ManyToOne
    @JoinColumn(name = "reservation_id")
    private Reservation reservation;

    @ManyToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)
    @JoinColumn(name = "user_id")
    private User user;
...
}

Third:

public class Reservation implements Serializable{
    private static final long serialVersionUID = -9007238193656173229L;

    @Id
    @Column(name = "id")
    private String id = generateId();
...
    @OneToMany(mappedBy = "reservation", cascade = CascadeType.REMOVE)
    private Set<CommentReserv> comments = new HashSet<CommentReserv>();
...

Then i get Reservation and User from DB...

Reservation reservation = this.reservationRepository.getReservationById(params.get("reservationId").toString());            
User currentUser = this.userRepository.getUser(principal.getName());

(I checked it. User is loaded correctly.) And set it to new CommentReserv instance.

commentReserv.setReservation(reservation);
commentReserv.setComment(params.get("comment").toString());
commentReserv.setUser(currentUser);

When i trying to save new CommentReserv, i get User copy in my DB. I tryed to remove cascadetype from CommentReserv, but it produces TransientObjectException. What is wrong with my code? Second night without sleep...

Answer 1

In my DB i have one user with id=0. It is strange, but hibernate assume that if user id = 0 then user is not exists in DB. Really strange. I just change id to 1 and it's work fine.