I am using a Flex client with BlazeDS remoting. The entity on the client side has a corresponding DTO object and the Long id translates to a Number class on the Flex side. Unfortunately Adobe designed the Number class in such a way that it cannot be null. Yes, a single class out of thousands of ActionScript classes that cannot be null!!!

When a new entity rematerializes on the server side the id is 0 instead of null. My entity is defined simply:


Is there any way to ask hibernate to interpret null and 0 as the same thing - unsaved entity?

Thanks.

what does the generated hibernate mapping file look like?
does it have any unsaved value specified in it??

have you tried some how through annotations to set the unsaved value to 0 and see if that helps..
<id name=”id” column=”id” unsaved-value=”0″>

Also initialize the id to zero by default and see if that helps at least from your client side..

@Id
@Column(name="ID")
@GeneratedValue
protected Long id = new Long(0);

Hope this helps,
Latha.

Thanks Latha. I ended up trying @PrePersist annotation which did not solve the problem. I could not alter the id before the entity persisted.



Then i found a bug on Flex serialization - abandoned and unlikely to be fixed.

Finally i decided to change id to primitive long, so now 0's are not a problem. Hibernate assumes 0 as uninitialized entity.