Can I change the record an EJB points to from within the bean?

Question

I have a problem which I hope someone can help with.
I'm programming an EJB application which references several 'price list' type tables. An order will contain several option selections, which reference options, which each have an associated price. A system administrator is going to have to change and update these prices as tim egoes on, and may want to remove options etc. In order to ensure that existing orders don't have their values changed as a result of this we've decided that, when options have their price changed, we actually create a new option record, setting an end_date on the old option record to signify that it's no longer valid for new orders being raised. In the option Beans set cost method, I set the end_date property of the bean and call the create method of the options own home interface.
My problem is this: At the moment I return the newly created option as a return value of the setCost method but I feel this is a little graceless. Ideally I'ld like to change the bean to point at the new record as part of the set method itself, that way, to the client it would appear as if tey were still looking at the same bean but with an updated price, which is what you'ld normally expect from a set method. Can this be done?

Answer 1

Um, yeah - graceless is a good word. Essentially, you've stuck business logic into the EntityBean (I'm guess that's what you're using for data persistence). What you need to do is move the Option.create() method out of the EntityBean and use a StatelessSessionBean to execute the logic: update the old Option record, create the new one, then return the result.
As an aside, it's considered Not Very Good Practice to have client applications directly accessing EntityBeans: serializable DataObjects (e.g. JavaBeans, not EJB) or ValueObjects (non-"changeable" DOs) are better at passing data back and forth between client applications and application container. Ideally, this flow is like this:
client <- VO -> SSB <- DO -> EntB
This lets the EntityBean just worry about getting data in/out of storage, the (business) logic resides in the StatelessSessionBean and the client interacts/shows the data.