Bean validation on associations not working when using generation strategy IDENTITY

问题

I have got the following Parent, Child and Subchild entities:

@Entity 
public class Parent {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "ID", nullable = false, precision = 20)
private Long id;

@Valid
@BatchSize(size = 5)
@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true, mappedBy = "parent")
private List<Child> childs = new ArrayList<>();

...

}


@Entity
public class Child {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "ID", nullable = false, precision = 20)
private Long id;

@NotNull
@ManyToOne(optional = false)
@JoinColumn(name = "parent_id", nullable = false)
private Parent parent;

@Valid
@BatchSize(size = 5)
@Size(min = 1)
@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true, mappedBy = "child")
private List<Subchild> subchilds = new ArrayList<>();

....

}

@Entity
public class Subchild {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "ID", nullable = false, precision = 20)
private Long id;

@NotNull
@ManyToOne(optional = false)
@JoinColumn(name = "child_id", nullable = false)
private Child child;

....

}

Notice, that there is a @Size(min=1) validation on the subchilds association.

Parent, child and subchild are linked by a OneToMany association and the child and subchild are always updated (and persisted) together with the parent:

  @Service
  public class ParentService {

    public Parent update(@NotNull @Valid Parent parent) {

         return parentRepository.saveAndFlush(parent); 
   }

  ....
  }

Until recently I used an Oracle database and the JPA sequence strategy to generate the primary keys. This worked fine so far:

I could create parent entities together with some childs and subchilds
I could also add some additonal childs with subchilds entites after the parent has already been saved.

However, now I'm using a Postgres database and the sequence strategy has been changed to Identity. The above 2nd use case does not work anymore. As soon as a parent is once saved, I can't add any childs afterwards. A bean validation exception occurs that says my subchilds are empty. However the collection is initialized and not empty in my ParentService, it is only empty in the validator. If I remove the @Size(min=1) validator completely, everything is saved correctly. It seems to me that the subchild association is not correctly "passed on" to the bean validation.

This is an issue with GenerationType.Identity. If I am using GenerationType.Sequence everything works fine.

Any ideas?

Reproducable Testcase:

@RunWith(SpringRunner.class)
@DataJpaTest
public class ParentRepositoryTest {

@Autowired
private TestEntityManager entityManager;

@Autowired
private ParentRepository parentRepo;

@Test
public void test() {
    
     Parent parent = new Parent();

     Parent savedParent = entityManager.persistAndFlush(parent);

     Child child = new Child();
     Subchild subchild = new Subchild();

     subchild.setChild(child);
     child.getSubchilds().add(subchild);

     child.setParent(savedParent);
     savedParent.getChilds().add(child);

     parentRepo.saveAndFlush(savedParent); // it throws a validation error here
     
}

来源：https://stackoverflow.com/questions/63131834/bean-validation-on-associations-not-working-when-using-generation-strategy-ident

标签

hibernate

jpa

spring-data-jpa

bean-validation