I need Oracle Java 7 for software running on my Mac, but do not wish to have the plug-in available in my web browsers.
How can I accomplish this configuration and maintain it across Java upgrades?
I'd say just install java as normal. Afterwards go to
System Preferences → Java (bottom row) → Security
and uncheck "Enable Java content in the web browser".
That should do it, and I would very much expect it to remember the setting after an update.