Hello.
It's better to official support JavaScript in Arma 3 engine than Java. Because JavaScript is a prototype-based scripting language that is dynamic, is type safe, and has first-class functions. So it's much friendly to common community programmers which are outnumbers advanced native Java programmers. Also JavaScript is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles, which is powerful enough for difficult programming tasks.
Inspired by
JavaScript for ARMA addon.
http://forums.bistudio.com/showthread.php?156304-JavaScript-for-ARMA&highlight=typeName
Thanks.