Hi all

Please help me with my incorrect understanding of mappings, cascade and flush.
I have various data model classes that are linked: Event --> EventDateTime --> TicketCategory -->ManyToMany<-- Block.
The Block data model is also linked via another path: Event --> Venue --> Layout --> Block --> Seat.
Currently my test data does not include any Layout, Block and Seat data. There is only Event, EventDateTime, TicketCategory and Venue data.

Whenever a TicketCategory have loaded (via a EventDateTime instance being loaded), when a flush it performed by Hibernate, I get the flush exception below (collection [...model.ticket.TicketCategory.blocks] was not processed by flush()).
I assumed that since the link between the TicketCategory and Blocks is a lazy loaded, cascade none (default), Hibernate not not care about this link when saving the TicketCategory. If I call ticketCategory.getBlocks() prior to saving the data, obviously Hibernate then initializes the (non-existing) lazy loaded collection of blocks and the error does not occur.

Q1: Why when working with an EventDateTime instance are the corresponding TicketCategory instances loaded by Hibernate? Cascade is default (none) and lazy loaded.

Q2: Why does TicketCategory care about Blocks when it is flushed if the cascade is none? Is it the validation annotations or is this how Hibernate works?



Exception is:


Hibernate 3.5.5-Final
Hibernate Annotations 3.4.0.GA
Hibernate Validator 4.1.0.Final
Spring 3.0.4.RELEASE

If anyone can please correct my incorrect mappings and understanding, that would be great.

Thanks
Aisling

The error message indicates that something is happening during the flush that causes non-initialized lazy objects to be initialized. It is fairly easy to find out what is triggering the loading. Put something like this in your EventDateTime.getTicketCategories() and TicketCategory.getBlocks() methods:



Then you will get a nice output of stacktraces and you will see exactly what other code is calling the getter methods. Typical sources of the problem can be an Interceptor, an event listener or maybe the @NotEmpty annotation on the getTicketCategories().

Thanks for the suggestion (should of thought of that myself - doh) and you were right, its the @NotEmpty annotation that causes the EventDateTime data to load the TicketCategory instances. I do want to use the validation annotations but not if it causes lazy loading collections to be loaded. Need to do some more reading on this. Thanks again.

Maybe you can implement your own validation rule. I have not any experience with that but it should be possible to check if the collection is an instance of org.hibernate.collection.PersistentCollection and then use some methods in that interface to avoid initializing the collection. See http://docs.jboss.org/hibernate/core/3. ... ction.html

Thanks for the link (looking...).

For the moment, I am using a group to determine when the collection should be checked for data.



(I knew about groups, my brain was obviously not in gear this week.)
Thanks.