Hibernate updating one to many collection when object removed from collection

Question

I have run into a nasty bug with jpa and hibernate. I have a billing class with the following annotation:

@OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER)
@JoinColumn(name="ch1_id", referencedColumnName="id")
private List<BillingItem>billingItems = new ArrayList<BillingItem>();

Now I need to filter deleted items from the collection but cannot use anything but jpa. No hibernate specific annotations allowed. So I wrote a post load function:

@PostLoad
public void postLoad() {
    ArrayList<BillingItem>tempItems = new ArrayList<BillingItem>();

    Iterator<BillingItem> i = this.billingItems.iterator();
    BillingItem item;
    while(i.hasNext()) {
        item = i.next();            
        if( item.getStatus().equals("D")) {
            tempItems.add(item);                
        }                       
    }

    this.billingItems.removeAll(tempItems);
}

However when there are deleted items to filter I'm seeing

Hibernate: update billing_on_item set ch1_id=null where ch1_id=? and id=?

which produces an exception because ch1_id is a foreign key and cannot be null. However hibernate is binding the parameters to correct values. Why is this update occurring in the first place? How do I correct the error?

Thanks in advance,

Randy

Answer 1

By removing the items from the collection, you're telling Hibernate that the association between the two entities doesn't exist anymore, so obviously, Hibernate removes what materializes this association in the database: it sets the foreign key to null.

What you probably want is just a getter in your entity that returns only the non-deleted items:

public List<BillingItem> getNonDeletedItems() {
    List<BillingItem> result = new ArrayList<BillingItem>();
    for (BillingItem item : this.billingItems) {
        if (!"D".equals(item.getStatus()) {
            result.add(item);
        }
    }
    return result;
}

Answer 2

The @OneToMany(cascade=CascadeType.ALL, fetch=FetchType.EAGER) line says that it will cascade ALL updates. Look into CascadeType .