Howdy -- I was told it was something like, "Entity beans are always connected to an underlying persistent store, which means they are inherently transactional." Which I think translates to something more like, "We want to make it more harder for you to mess up the database." People can still mess things up, of course, with a bad combination of transaction attributes, but *forcing* you to put transaction attributes on the key methods of entity beans means you have to acknowledge that you're doing important things (INSERT, UPDATE, etc.) to the cricital data. So it's just a protection.
Of course, you could have a development tool that puts in all transaction attributes defaults for you, so that you STILL don't have to acknowledge transactions with your entity beans... but a decent tool will put in "Required" as the default, so that you WILL have a transaction unless you specifically make a point of saying that you don't support a transaction or something.
In other words, the specification makes it a more work for you to *not* use transactions with entity beans.
One more big difference between
EJB and jini -- EJB gives you all sorts of protections so it's harder to really do Bad Things ("we don't completely trust you to protect the enterprise data"), while Jini says, "you are on your own... we trust you, and if you want to blow the place up, that's your business."
cheers,
Kathy
