@Validate and JPA Life Cycle and DefaultMergeEventListener

bennixview · **Joined:** Tue Oct 19, 2010 11:16 am **Posts:** 5

I want to validate detached entities after a merge via a ValidationListener in two steps. On @PrePersist the Constraints in the Group PrePersist.class and on @PostPersist the the Constraints in the Group PostPersist.class.

On OneToMany relations I want to Validate the associated beans with @Valid.

But in the @PrePersist Event in my ValidationListener the Root Bean has an empty Collection. And the method in @PrePersist will be called 2 times. Once with the Root Bean and once with the associated bean that should be in the @OneToMany collection. I expect that it will be called once with the root bean and that I get a Constraint like that:

RootBean : BeanA
LeafBean : BeanB
PropertyPath : beanBs[0].anyWrongValue

Waht I found out is that the copyValues Method in DefaultMergeEventListener gets an Object entity (Root Bean) with @OneToMany-collection size() == 1 and in the Object target the Root Bean has an empty @OneToMany collection.

What can I do?

The Problem is that in the ConstraintViolation the RootBean and the LeafBean is the same!

I use hibernate-core 3.6.0.Final !!! and hibernate validator 4.1

The associations in the Entities looks like that:

Code:

public class BeanA ... { ...
@OneToMany(cascade = CascadeType.ALL)
@NotNull
@Valid
private List<BeanB> beanBs = new ArrayList<BeanB>();
...}

public class BeanB ... { ...
@ManyToOne(optional = true)
@JoinColumn(name = "B_ID")
@NotNull
private BeanA beanA ;
...}

The ValidationListener looks like that:

Code:

...
@PrePersist
public void onPreChange(T object) { ....
   Set<ConstraintViolation<T>> constraintViolations = validator.validate(object, PrePersist.class);
...}...

wrungel · **Joined:** Thu Oct 21, 2010 5:48 am **Posts:** 9

I have similar problem with validation of an object graph.

I have two JPA entities: A and B. B is referenced by A as oneToMany reference:

Code:

   
  1       n
A --------> B

I installed EventListener for entity A with a @PrePersist method where I want to validate the entity.

Then I did the following:

Code:

EntityManager em;
A a = new A();
B b = new B();
b.setInvalidProperty();
a.addB(b);
em.merge(a);

I've debugged the DefaultMergeEventListener and observed, that at the runtime my @PrePersist callback method gets a copy of entity a (a_copy) without reference to b (the collection of B's in A was empty). Within the callback a_copy is then validated without referenced b entity.

The b entity is validated alone in the next call to @PrePersist callback method.

The ConstraintViolationException is then thrown but the RootBean and LeafBean are wrong: both the RootBean and the LeafBean are entity b.
Expected is: RootBean is a, LeafBean is b.

Is the object graph validation in @PrePersist callback possible at all?

Why the @PrePersist callback gets stripped entity without references?

If object graph validation in @PrePersist callback is not possible, are there any other suitable places in Hibernate stack to perform validation before a transient entity is persisted?

bennixview · **Joined:** Tue Oct 19, 2010 11:16 am **Posts:** 5

Hi wrungel,

did you tried also the latest version of hibernat core 3.6. I update to it becaus of TypeFactory.replace was deprected in 3.5.6 and i hoped that the newer version fixed the problem. For details see : http://opensource.atlassian.com/project ... e/HHH-5138

But with version 3.6 i also get the same problem.

wrungel · **Joined:** Thu Oct 21, 2010 5:48 am **Posts:** 9

bennixview wrote:

did you tried also the newest version of hibernat core 3.6. I update to it becaus of TypeFactory.replace was deprected in 3.5.6 and i hoped that the newer version fixed the problem. For details see : http://opensource.atlassian.com/project ... e/HHH-5138
But with version 3.6 i also get the same problem.

I tried it with version 3.6 only.

bennixview · **Joined:** Tue Oct 19, 2010 11:16 am **Posts:** 5

It looks as if the problem is already known.

http://opensource.atlassian.com/project ... e/HHH-1914

What can I do now ... ?