@kitkat1126
yep, just paste the code into terminal, hit enter and type in your password, to confirm the sudo command (root access)
with this code you cannot crash your Mac, even if the plist brick, it will redownloaded from apple, if it doesn't work.
The code just overwrite the string that allowes only a java version higher then the latest one by settings the latest one to be allowed to run.
@Marc Monarco
Apple blocked the latest Java versions via the XProtect "anti Malware" system wich came with 10.6 (maybe because its unsecure and is vulnarable). The modifcations mentioned here should only be done if you REALLY need to run a java applet on a website you trust as secure!
Otherwise just wait until apple or oracle releases a newer, more secure version of java, wich will automaticly will be allowed to run.
I hope apple releases a newer version via softwareupdate for 10.6.
10.7 and higher already need the oracle java install, wich can be found here: http://www.java.com/en/download/apple.jsp
The Settings for XProtect are stored in a plist file, wich is downloaded/updated every 24 hours when the mac starts up via a launchdeamon i think.