Criteria.DISTINCT_ROOT_ENTITY doesn’t prevent duplicated objects

I have following dao method:

@Override
public List<AdminRole> findAll() {
    Session session = sessionFactory.getCurrentSession();
    Criteria criteria = session.createCriteria(AdminRole.class);
    criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
    return criteria.list();
}

Actually I want to retrieve all entries from database.

Sometimes I see duplicates. This happens when I add user with AdminRole.

I have read that it is possible when I use EAGER fetch type and this should be fix adding following line:

criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);

But this doesn’t help me.

my mapping:

@Entity
@Table(name = "terminal_admin_role")
public class AdminRole {

    @Id
    @Column(name = "role_id", nullable = false, unique = true)
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "user_id")
    @SequenceGenerator(name = "user_id", sequenceName = "user_id")
    private Long adminId;

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

    public AdminRole(String role) {
        this.role = role;
    }

    public AdminRole() {
    }

    // get set

    @Override
    public String toString(){
        return role;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof AdminRole)) {
            return false;
        }

        AdminRole adminRole = (AdminRole) o;

        if (!role.equals(adminRole.role)) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode() {
        return role.hashCode();
    }
}

and

@Entity
@Table(name = "terminal_admin")
public class TerminalAdmin {
    @ManyToMany(fetch=FetchType.EAGER,cascade=CascadeType.ALL)
    @JoinTable(name = "admin_role", joinColumns = { 
        @JoinColumn(name = "admin_id", nullable = false) }, 
        inverseJoinColumns = { @JoinColumn(name = "role_id", 
                nullable = false) })
    private Set<AdminRole> adminRoles;      
    //...
}

P.S.

I cannot switch fetch type.

I don’t want to put this list into set.

Answer

There is no reason to use DISTINCT_ROOT_ENTITY or anything similar, all you need is:

session.createCriteria(AdminRole.class).list();

If you get duplicates, then you really have them in the database. Check the code which saves AdminRoles either directly or by cascading from other entities.

When cascading PERSIST/MERGE operations from other entities, make sure that the operation is cascaded to a persistent/detached AdminRole instance, not to a transient (new) one.

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