Updating java in linux
So, if you want to set Oracle Java 8 as default, no matter what other Java versions are installed, make sure that you install the oracle-java8-set-default package (which, again, should be automatically installed with the main Oracle Java Installer package in Ubuntu, but not in Linux Mint): If you don't want to make Oracle Java 8 default (it might still be set as default, depending on what other Java versions you may have installed), install the oracle-java8-installer with "--no-install-recommends": Note: removing the oracle-java8-set-default package does not undo all the changes (I have yet to find a way to do this properly).
If you don't want to set it as default, remove both oracle-java8-installer and oracle-java8-set-default packages, and then install oracle-java8-installer with "--no-install-recommends" (like mentioned above).
It's also important to note that the Oracle Java 8 installer is considered in alpha and is offered without any guarantees! If you ISP or router blocks the ports used by the Oracle Java 8 download servers, the installation may fail.
To view or change this option, click the Java icon in the Windows Control Panel or Mac OS X System Preferences to open the Java Control Panel, then select the Security tab.    Mac OS: You can download Java from Apple Support Downloads (Java 6 and below). Windows and Linux: You can download Java here or you can select the offline (full) installer for your operating system from this download page.
On Mac OS X 10.7.3 (Lion) and above, Java 7 is available here or from this download page. (If you are looking for Java 6, see the Java 6 FAQ page).
The PPA supports JDK8 for both 32bit and 64bit as well as ARM (ARM v6/v7 Hard Float ABI - there's no JDK 8 ARM Soft Float ABI archive available for download on Oracle's website).
As a reminder, the Web Upd8 Oracle Java PPA doesn't include any Java binaries, just a script that automatically downloads and install Oracle Java 8.