Spring or Hibernate not generating id when username is annotated with @email

Question

I currently have a completely working Spring application, tested very thoroughly and has been successfully running in production for over a year now. Recently, I wanted to have hibernate email validation on the username field. The username field is used for logging in and is also the email of our users.

When I annotate the username field with @Email, the id (annotated with @Id and @Generated(strategy = GenerationType.AUTO)) is not generated anymore and keeps the value null. This causes the hashCode to fail on a NullPointerException (No problem with this though). So for some reason, the id is not generated anymore due to the addition of an @Email annotation to the User.java Entity.

@Entity
@Table(uniqueConstraints = @UniqueConstraint(name = "username",
columnNames = "username"))
public class User implements Serializable, UserDetails {

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

    @Column(nullable = false)
    @JsonView(View.NoProfile.class)
    @Email
    protected String username;

    @Column(nullable = false)
    private String passwordHash;

    @JsonIgnore
    @ElementCollection(targetClass = Role.class, fetch = FetchType.EAGER)
    @Enumerated(EnumType.STRING)
    @CollectionTable(name = "user_role")
    private Set<Role> roles;

    @OneToOne(targetEntity = Profile.class, cascade = CascadeType.ALL)
    @JsonView(View.Public.class)
    protected Profile profile;

    @JsonIgnore
    private boolean accountNonExpired = true;
    @JsonIgnore
    private boolean accountNonLocked = true;
    @JsonIgnore
    private boolean credentialsNonExpired = true;
    @JsonIgnore
    private boolean enabled = true;

    public User(String username, String passwordHash) {
        this.username = username;
        this.passwordHash = passwordHash;
        this.profile = new Profile();
        this.roles = new HashSet<>();
        roles.add(Role.ROLE_USER);
    }

    User() { // jpa only
    }

    public Profile getProfile() {
        return profile;
    }

    public Long getId() {
        return id;
    }

    public void setPasswordHash(String passwordHash) {
        this.passwordHash = passwordHash;
    }

    @Override
    public Set<? extends GrantedAuthority> getAuthorities() {
        return roles;
    }

    @Override
    @JsonIgnore
    public String getPassword() {
    return passwordHash;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    @Override
    public boolean isAccountNonExpired() {
        return accountNonExpired;
    }

    @Override
    public boolean isAccountNonLocked() {
        return accountNonLocked;
    }

    @Override
    public boolean isCredentialsNonExpired() {
        return credentialsNonExpired;
    }

    @Override
    public boolean isEnabled() {
        return enabled;
    }

    public void resetProfile() {
        this.profile = new Profile();
    }

    public void addRole(Role role) {
        this.roles.add(role);
    }

    public void setAccountNonLocked(boolean accountNonLocked) {
        this.accountNonLocked = accountNonLocked;
    }

    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }

    @JsonView(View.Public.class)
    public int getReference() {
        return username.hashCode();
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        User user = (User) o;

        return username.equals(user.username) && id.equals(user.id);

    }

    @Override
    public int hashCode() {
        int result = username.hashCode();
        result = 31 * result + id.hashCode();
        return result;
    }
}

Answer 1

The problem can be that when trying to save the user hibernate checks if it is valid. If there is a problem with the username email format hibernate does not try to save it, thus id does not generate an id.

But what happens with the validation error? I think it's possibly beeing masked by the NPE you talk about in hashCode method. Try to rewrite your hashCode taking care of possible NPE, and check for hibernate constraint violations.