strange loading of entity that doesn't exists

cmout · **Posted:** Fri Apr 07, 2006 8:39 am

I'm facing a very strange behavior of session.load(MyClass.class, <primaryKey>). Hibernate give me back an object (MyClass$$EnhancerByCGLIB$$...) even if the row with primaryKey doesn't exist in the database table. I expected an Exception instead of these proxy object.

Changing the code to session.get(...) than the result is null.

I'm using hibernate-3.2cr1 with hibernate-annotations-3.1beta9 (build the day before yesterday from SVN).

Any help is welcome.

Regards
-chris

gschrader · **Joined:** Tue Dec 09, 2003 3:27 pm **Posts:** 21

I'm getting this for known pk's as well. I'm not sure if I'm missing an annotation or something as the old mapping files will return a correct object. Is this a bug or something I'm missing on my part?

damnhandy · **Posted:** Fri Apr 21, 2006 1:46 pm

You're getting back a proxy which represents the class your after. Hibernate uses CGLIB to generate proxies at startup.

Ryan-

gschrader · **Joined:** Tue Dec 09, 2003 3:27 pm **Posts:** 21

ok yeah I figurred my old mappings were using proxies as well but it appears that maybe they weren't.

The reason I thought something was wrong is that the proxies don't show up in our IDE's debugger correctly (every property shows up as null, I see now that the getter methods still return the proper values) however if you use the session.get method instead it appears as though it doesn't use a proxy, hence why I thought there was a problem with the session.load method with annotations.

gschrader · **Joined:** Tue Dec 09, 2003 3:27 pm **Posts:** 21

ok so doing a @Proxy(lazy=false) annotation will turn off the proxy. Not sure why we had our old mapping files with lazy="false" to begin with.

cmout · **Posted:** Fri Apr 21, 2006 7:20 pm

after all it seems to me that it's just a bug in H3 (with annotations). It doesn't make sense to get a proxy of a non-existing object, does it?

-chris

gschrader · **Joined:** Tue Dec 09, 2003 3:27 pm **Posts:** 21

yes I would say it would be, I think it's also strange that it wouldn't create a proxy using a session.get or a fetching objects using a criteria.

numeropi · **Joined:** Tue Nov 15, 2005 4:21 am **Posts:** 11

It does make sense to have a proxy to an nonexistant object. From the docs (emphasis mine):

Quote:

Note that load() will throw an unrecoverable exception if there is no matching database row. If the class is mapped with a proxy, load() just returns an uninitialized proxy and does not actually hit the database until you invoke a method of the proxy. This behaviour is very useful if you wish to create an association to an object without actually loading it from the database.

There's no way it can throw an exception for nonexistance before hitting the database. load() should only be used if you are sure that the object exists.