@Entity
@Inheritance(strategy = InheritanceType.JOINED)
public abstract class Element {
    @Id
    @GeneratedValue
    @Column(name = "`id`")
    private Long id;

}

@javax.persistence.Entity
@PrimaryKeyJoinColumn(name="`id`")
public class Entity extends Element {
    private String value;

    @ManyToMany(cascade = {CascadeType.MERGE,CascadeType.REFRESH} )
    @OrderColumn(name="`order`")
    private List<Entity> types = new ArrayList<>();

}

entity_types
-------------------------
entity_id, type_id, order
and everything is persisted properly..