Duplicate entity

iancurtis · **Posted:** Mon Jan 29, 2007 4:48 am

Hi!

I have a rather large dm object that I would like to duplicate. The dm in question is an article object and an article is placed in one or more categories.

I have implemented the clone method in the article class:

Code:

public Object clone(){

Article art = new Article();
art.setCategories(this.getCategories());

return art;

}

And my actual clone code looks like this:

Code:

ArticleHome ahome = new ArticleHome()
Article art = ahome.findById(id);
Article nart = (Article)art.clone();
ahome.persist(nart);

Not surprisingly, this doesn't work. I get:

ArticleHome:49 - persist failed

org.hibernate.HibernateException: Found shared references to a collection: com.ian.dm.Article.categories

How do I get around this?

All the best!

LaLiLuna · **Posted:** Mon Jan 29, 2007 5:40 am

set the primary key to null

iancurtis · **Posted:** Mon Jan 29, 2007 6:34 am

Ok, but that doesn't solve my problem in a convient way. I have more then one collection mapped to an article, and then I have to make duplicates of every object that is a part of the collection; first for every Category in the collection and then for every other object type that are a part of a collection in my article object.

max · **Posted:** Mon Jan 29, 2007 6:46 am

no you just have to copy the collection; not the elements! (assuming it is a manytomany relationship you have)

iancurtis · **Posted:** Mon Jan 29, 2007 9:02 am

Ok!

Now, I don't get any errors but the categories aren't copied.

How do I make a copy of the collection? Does the following work:

Code:

Set<Category> d= new HashSet<Category>();
d.addAll(this.getCategories());

My hbm-file looks like this:

Code:

  
<set name="articles" table="category_article" cascade="all" inverse="true" lazy="true" order-by="(article) desc">
<key column="category"/>
<many-to-many column="article" class="com.ian.dm.Article"/>
</set>