EntityExistsException

[Tang Yue]

In persistance spec 3.7:
"
The EntityExistsException may thrown by the persistenc
operation is invoked and the entity already exists. The E
thrown when the persist operation is invoked, or the Enti
PersistenceException may be thrown at commit time. "

But in the study guide:
"
For a given entity A, the persist method behaves as follows:

If A is an existing MANAGED entity, it is IGNORED. However, the persist operation
cascades as defined below. "

Isn't the two contradictory? If one invokes persist(A) where A is a managed entity and surely already exists, will this persist() be ignored or an EntityExistsException be thrown?

[Jaikiran Pai]

"
The EntityExistsException may thrown by the persistenc
operation is invoked and the entity already exists. The E
thrown when the persist operation is invoked, or the Enti
PersistenceException may be thrown at commit time. "

Looks like you missed out some part of the sentence while posting it here Could you please edit your post to include the entire statement.

[Tang Yue]

Oops, I paste the full text of that quote here:
"
EntityExistsException
The EntityExistsException may thrown by the persistence provider when the persist operation is invoked and the entity already exists. The EntityExistsException may be thrown when the persist operation is invoked, or the EntityExistsException or another PersistenceException may be thrown at commit time. "

[Jaikiran Pai]

Originally posted by Tang Yue:

The EntityExistsException may be thrown by the persistence provider when the persist operation is invoked and the entity already exists. The EntityExistsException may be thrown when the persist operation is invoked, or the EntityExistsException or another PersistenceException may be thrown at commit time. "

Since it says "may", I think its upto the persistence provider to decide whether to throw the exception or not.