Is Java disabled in the browser maybe?
Safari, blocked plug-ins…
Locate the version of Java that’s installed on your Mac OS X system.
1. Open the Utilities folder and run the Terminal application.
2. Type java -version and press Enter.
(space between java & -v important)
The version of Java that you have installed will then be displayed on the screen.
Java for OS X 2012-006: How to re-enable the Apple-provided Java SE 6 applet plug-in and Web Start functionality