simple hibernate self referencig - parent child association

Question

The classes

class Bean {

private List<Radicacion> getReferencias() {
    List<Radicacion> refs = DAO.findAll(Radicacion.class);
    return refs;   
}

private Radicacion getRadicacion() {  
    Radicacion r = DAO.findById(Radicacion.class, new Integer(33) );
    return r;
}

private void guardarDependencias() {
    Iterator<Radicacion> itRad = getReferencias().iterator();
    while (itRad.hasNext()){
        Radicacion ref = itRad.next();          
        getRadicacion().getRadicacions().add(ref);
        ref.setReferencia(getRadicacion());             
    }
}
}

////////

class Radicacion {
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "referencia")
public List<Radicacion> getRadicacions() {
    return this.radicacions;
}
public void setRadicacions(List<Radicacion> radicacions) {
    this.radicacions = radicacions;
}

    @ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.LAZY)
@JoinColumn(name = "referencia_asociada")
public Radicacion getReferencia() {
    return this.referencia;
}
public void setReferencia(Radicacion radicacion) {
    this.referencia = referencia;
}           

}

the problem

i need that all Radicacion objects contained provided by the getReferencias() method end up in the getRadicacion().getReferencias() collection.

whenever i call guardarDependencias (save dependencies in english) nothing happens. The original getRadicacion.getReferencias() remains unchanged.

things to ponder

if i insert a DAOBase.merge(ref); in the iteration, it does not produce any sql output. It makes me think that ref is already loaded as persistent, so why hibernate fails to update its status when i set the link to getRadicacion()?
if I insert System.out.println( HibernateUtil.getCurrentSession().contains(ref)); in the iterator, it prints out true.
If i create other asociations,persistence works fine. The problem might have something to do with the self reference.

Thanks for your help

score 0 · Accepted Answer · answered Sep 18 '12 at 07:07

0

What you code suggest that you want to add all Radicacions ( which you get by (DAO.findAll(Radicacion.class) to a Radicacion with id 33. Also Radicacion is self referencing that is it has a reference to itself as well as has a collection of Radicacion (Parent- Child relation)

The first thing you should check is that if the method guardarDependencies is running inside a transaction? I don’t see any transaction management code. If no sql is outputted (and you expect it) during session usage then the first suspicion goes to whether it is run under a transaction.

You can also run Hibernate in DEBUG mode and see what is happening under the hood. it's very helpful to get at the root problem

answered Sep 18 '12 at 07:07

Shailendra

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hi shailendra, you are right, Radicacion is a self referencing class. As for the transaction code, it is a filter that begins a new transaction for every request and does a commit when the request is about to end. – demonz demonz Sep 18 '12 at 14:43
See http://stackoverflow.com/questions/3393515/jpa-how-to-have-one-to-many-relation-of-the-same-entity-type and http://stackoverflow.com/questions/5329015/hibernate-annotations-self-referencing-class for proper usage of self referencing relations – Shailendra Sep 18 '12 at 18:21

simple hibernate self referencig - parent child association

1 Answers1