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Re: [eclipselink-users] Application Developer Responsibilities when overriding java.lang.Object.clone() in EclipseLink JPA mapped classes? 
Hi Doug,
As long as the clone methods on the targets of your relationships are implemented correctly, you should be fine with cloning the way you suggest.
When weaving is enabled, EclipseLink does weave in a _persistence_post_clone() method. That code is added after the call to super.clone() and does some clean-up of the weaved code. 

Are you seeing problems?

-Tom

Gschwind, Doug wrote:

Hello everyone,
I didn’t find any information on the wiki on this topic, and that may simply be due to no change in the contract regarding how overriding implementations of clone() should be implemented in EclipseLink JPA mapped classes. However, I am looking for confirmation of that.
Suppose I have a JPA mapped class, with relationships to other JPA mapped classes as follows: 


@Entity

public class Container extends Object

{

    @OneToOne

    private A a;


    @ManyToOne

    private B b;


    @OneToMany

    private List<C> cs;


    @ManyToMany

    private List<D> ds;

}
Now suppose I wish to create instances of Container by cloning persistent instances. What I am looking for are any differences in the overriding clone() implementation if the Container class were defined as above, or if the Container class was not JPA mapped and had none of the above annotations. Would the following method suffice within the JPA mapped Container class, assuming the overriding implementation of clone() on the JPA mapped A, B, C, and D classes were equally appropriate: 


@Override

public Object clone()

{

    Container result = (Container) super.clone();


    result.a = (A) this.a.clone();

    result.b = (B) this.b.clone();


    result.cs = new ArrayList<C>(this.cs.size());

    for (C sourceC : this.cs)

    {

        C cloneC = (C) sourceC.clone();

        result.cs.add(cloneC);

        cloneC.setContainer(result);

    }


    result.ds = new ArrayList<D>(this.ds.size());

    for (D sourceD : this.ds)

    {

        D cloneD = (D) sourceD.clone();

        result.ds.add(cloneD);

        cloneD.setContainer(result);

    }

}
If not, what differences in the above implementation would be recommended for use in the JPA mapped Container class? 


Thanks,


Doug







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