[javaee-spec users] Re: default resources

From: arjan tijms <>
Date: Fri, 14 Nov 2014 19:06:03 +0100


On Thursday, November 13, 2014, Romain Manni-Bucau <>

> Is it a real issue or just a theorical one? I mean default resources
> are generally a bad choice for real apps since you are not sure what
> you get so for me their purpose is related to testing so is that such
> a big deal?

I agree that the default resources are primarily a facility for tutorials,
people just starting, testing and simple applications.

Yet, a "simple application" does not necessarily mean non-production
application and even does not mean non-critical application. So I don't
agree that a "real application" should not use default resources.

For instance running apps that have modest persistence
requirements in resource constrained environments (think IoT among others)
the default datasource is an extremely convenient facility. In such
environments and for such apps installing a full blown external DB is often
not only unnecessary but also not even possible.

It's true that a portable app would not know what the exact nature of the
persistent store is, but A) if the persistence requirements are modest this
may not matter and B) for actual deployments to a specific server this -is-
of course known.

I think we should steer away from the thought that Java EE servers are
*exclusively* used by big corporations on big servers for apps with heavy
persistence requirements that are operated and provisioned by large teams.

Java EE servers are increasingly being used for smaller and smaller
applications, and I think that's a very exciting thing. IMHO Java EE should
be able to both scale up and down, and default

Kind regards,
Arjan Tijms

> Romain Manni-Bucau
> @rmannibucau