Need help with Hibernate? Read this first:
http://www.hibernate.org/ForumMailingli ... AskForHelp

Hibernate version: 3.1

Name and version of the database you are using: MS-SQL Server 2000 OR HSQLDB


I am just wondering...

If it is possible to define a user defined collection Class, and have it interact with Hibernet. In additionally, works exactly same as the Set, List, or Map?

For example:
With the Annotation of @ManyToMany, between Table A and B; Hibernate will create a new Table call A_B with all the required columns.

Therefore, is that possible for me to create a classType called "ListenerSet" which work exactly the same as the Java Set class and create the same Tables. In addtional, with the listener trigger in the class?

(Note that "ListenerSet" can be implement from Set)



Currently, I implement everything as Set. However, when someone modify the DataTable; I would like to notify all the users that DB has been changed and do whatever next.




Thank you for your time....
Jeremy

I'm not sure what hooks hibernate has for inserting callbacks (listeners) - howevre, if you are using JBoss you can make use of the pre-event or post-event listeners or if you are using a Spring framework you could make use of AOP to drop a listerner in that way, and thus you can continue using java.util.Set.
Alternatively, why not just make the notification from the update method of the DAO if you are happy to embed it in code?

Ok, had a quick search and hibernate does indeed allow listeners to be registered.
Have a read of http://www.hibernate.org/hib_docs/v3/re ... vents.html

I suspect you want a pre-update (or post is better if they have one) listener that checks to see if you parameters of interest are being changed, and then make the notification to your users.

This is a much cleaner way of doing it, than creating custom Collection types.