JPAContainer- how to get the id of commited item

Andre Peters

Hi,

we use the jpacontainer 2.0 with eclipselink and postgres.
I need to know, how i get the generated id from an new created item after calling jpacontainer.commit()?

I supposed that the item will be updated after commit with the generated id, but the id is still 0 and item.isPersistent() returns false.

Any suggestions for that issue?

Last updated on Feb, 24th 2012

Marko Grönroos

Are you trying to get it from the new container item or from the entity that you added? If you try to get it from an entity that you've added with addEntity(), you need to get the persisted entity from the container using the item ID that you get with addEntity().

Andre Peters

Hmm, ok i have try it, but the JPAContainer does not know the generated UUID. After some investigation i have found the function clear() in BufferdeContainerDelegate. This function delets all known items from the JPAContainer. And this function will be called at the end of commit();

180	    private void clear() {
181	        deltaList.clear();
182	        addedEntitiesCache.clear();
183	        addedItemIdsCache.clear();
184	        updatedEntitiesCache.clear();
185	        deletedItemIdsCache.clear();
186	    }

clear()

So, if i called getItem() with the UUID after the commit(), the cache is empty and the result is an Exception: "You have provided an instance of an incorrect PK class for this find operation. Class expected : class java.lang.Long, Class received : class java.util.UUID."

Last updated on Mar, 2nd 2012

Victor Röder

Hello Andre,

maybe a little bit too late, but maybe others are interested in the answer as well. When you are using JPAContainer with a buffered entity provider (such as CachingBatchableLocalEntityProvider - which is the default one, I think), you get back an UUID as Item-ID from the JPAContainer, as long as you do not do a commit on the container. After that you have to use the ID given by the database to retrieve your EntityItem again.

Example:

JPAContainer<Contact> contactContainer = JPAContainerFactory.make(...);

Contact contact = new Contact();
contact.setDepartment("xyz");
contact.setEmail("");
contact.setGender(Contact.GenderListing.MALE);
contact.setName("Abc");
contact.setPhone("1234");

UUID uuid = (UUID) contactContainer.addEntity(contact);

EntityItem<Contact> contactEntityItem = contactContainer.getItem(uuid); // use UUID to retrieve the EntityItem

contactContainer.commit(); // *now* the entity item is persisted to the db

EntityItem<Contact> item2 = contactContainer.getItem(contact.getId()); // *now* we have to use the ID of the database

Hope this helps,
Victor

Kim Zeevaarders

Thx m8,

Exactly what I needed!

Regards,

Kim

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JPAContainer- how to get the id of commited item

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