Env, AutoCloseable and abstraction

This is somewhere between feedback and a question. Or I just miss something.

Currently creating and using an Env requires proper error handling via try-resource (AutoCloseable). At the same time I would like to hide the details of “the database” so I have a data access abstraction.

It is my understanding that the Env is typically opened at application startup and closed on application shutdown. So the resource is used roughly for the lifetime of the application.

I see two ways to have my abstraction:

1. I make it AutoCloseable too, so it is treated as the “resource” and it in turn will close the Env underneath.
2. I don’t use Env for the lifetime of the application but create it when needed. This basically means per request, what feels wrong, but who knows…

So my question is: Is there any way Env does not need to be a resource that requires AutoCloseable? Because this cascades upwards trough the application right up to the “main” what feels kind of ugly. Maybe it is “good enough” to have a “destructor” cleanup what needs to be cleaned for Env? Everyone who has a reference to Env could continue to close it explicitly but if not Env would take care of itself? Is something like that possible?

Or is it reasonable to start with creating an Env for each request? Or is there another way to handle Env that does not cascade/leaks AutoCloseable beyond abstractions?

[benalexau]

Assigning it to a field is fine.

Are we OK to now close this ticket?

[jbee]

The “trick” seams to be to not assign a AutoCloseable to a local variable (without a try-with-resource). That would give you a warning. Assigning it to a field is fine.