On Wed, Mar 21, 2012 at 9:16 AM, Tom Mueller <tom.mueller_at_oracle.com> wrote:
> These can be any system property value, including those passed with -D on
> the java command line (use create-jvm-options to set) and system properties
> (use create-system-properties to set).
>
Great; thanks. FWIW I noticed that the Administration Guide doesn't make
mention of this really excellent facility (or at least searches for "system
property" and "system properties" in my PDF reader turned up how to set
them, but not that they get expanded when in ${dollarBracket} form).
Does this also mean that I could use them in deployment descriptor files
(perhaps non-portably)? Or only domain.xml configurations (and templates)?
For example, if I put this in a persistence.xml somewhere:
<jta-data-source>${myApplicationDataSource}</jta-data-source>
...would it expand (if the property is set, of course)? (If the property
were not set, would it expand to the empty string, or to the literal string
"${myApplicationDataSource}"?)
I recognize this is probably a crazy thing to do and am not entirely
serious here; just trying to grok all the possibilities. (It has always
bothered me that whereas all the other deployment descriptors offer up a
level of indirection for resource references, I have to specifically
mention a global JNDI lookup (which could of course be java:app/env-scoped)
for a data source.)
Best,
Laird
--
http://about.me/lairdnelson