That's a fascinating question. I don't know if this is an option or not.
The spec doesn't require Glassfish to actually support an unexploded WAR file, as the WAR file is simply an artifact for deployment. However, it doesn't GUARANTEE that a WAR file will be exploded either (so you need to code your application to consider both scenarios, from a portability concern).
So, GF simply may not offer this as an option. Pretty sure it does, but just saying it's possible for it not too.
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