|Tip 70||Turn Off Java|
Java doesn’t come as an out-of-the-box install on OS X Mountain Lion, but it will be installed automatically when an app needs it. Any app you install that needs Java will therefore install it the first time it runs, but this raises an issue: Java has persistently been proven to be a serious security risk.
One solution is to simply turn off Java unless you need it. To do this, open Java Preferences, which is in the Utilities folder of the Applications list of Finder, and then remove the check alongside Enable Apple Plug-In and Web Start Applications. Then remove the checks under the On heading in the list of Java SE engines installed on your system.
Should an app start that needs Java, you’ll be shown an error to the effect that Java isn’t installed. Simply repeat the previous steps in reverse and enable Java—but don’t forget to disable it again afterward!
You might also want to disable access to Java within Safari, bearing in mind this is a typical attack vector for malware. To do so, start Safari, start System Preferences (application menu→Preferences), and select the Security tab. Then remove the check alongside Enable Java.