You can validate the script right in Lin Castor before saving/activating it.
For example I have a JIRA app wrapper which looks for anything staring with
[crarko adds: I tested this, and it works as described. I tried it in 10.10 beta 2, and it also worked there.
And then checked that the reported version of Java was 1.6 on each Mac.
Web applets still use the up to date, secure version 1.7 plugin.
I sometimes find the Java setup on my various Apple devices to be a mystery.