JBoss 4.2.2
MySQL 5.0

Is it possible to use an entity bean as a parameter to a stateless session bean method? I would guess so, but...

I have one SLSB something like this:



and another SLSB:



Whatever I try, I can't do anything much with foo in methodY. I either get LazyInitializationExceptions, or if I merge the foo entity, I get other exceptions related to stale states etc. Isn't this supposed to work? Shouldn't the transaction in the first SLSB propagate to the second one, not causing any lazy exceptions?! Am I missing something obvious?

This might not exactly answer your question but my guess is that entity managers are not the same. I do believe in hibernate you have a way to say a session-and probably therefore an entity manager-is bound to a transaction scope which means you will get the same session so you won't have these problems. however, if this is unavailable in the JPA world (or hibernate JPA world) you will have to initialize all lazy properties manually. You will have the same nature of problem if you cache this entity.


Farzad-

Giving it a good night's sleep, I found the problem. The findFooEntity method was not annotated correctly.

I have annotated my SLSBs with NOT_SUPPORTED as the default transaction attribute (i.e. annotated the class). However, this makes the system very error prone, as forgetting to annotate single methods generate exceptions when lazy loading etc. Changing the default to SUPPORTS solved my problem (or, of course, annotating the findFooEntity method).

Is there any best practice regarding this? Any pros and cons?

Any tips on how to debug scenarios like this? I think it's a bit tricky to figure out where it goes wrong :-)