I know that hibernate can do presistence the object to database.

However, can hibernate handle the synchronization from database to object?

That means if there is some changes in database (the changes are done through some other ways), can hibernate know there is some changes in the database and hibernate can be notified for these changes?

You can use refresh, which hibernates updates its cache/object info from the database.

Don't think there is any automatic way

Thanks.
I have read a lot of things and I also think there is no way to automatically update the object from database. That is what I mainly concern.

I don't think it's even technically possible. It would imply that you've got some sort of trigger (to use the db vocabulary) that would call some sort of listener. I don't if this feature even exists in any of the existing db (though I'd be interested in knowing it if ever possible).

So, the only solution you have is to call refresh(), or clear() the session so as to be sure hibernate will be forced to access the db to get the object, so as to be more up to date.

I think there are 2 ways to realize this.
1. by trigger. In database, write some trigger to call corresponding application.
2. Using message. In database, broadcast the message.
However, both of these ways need some work in database side. I am not sure database can support this or not. However, I think these should be supported.