How to Install Oracle JDK 8 on Kubuntu 15.10 Wily 32-64bit Linux+GNU Easy Guide

Download Oracle Java SE JDK8 for Linux.

Double-Click on the tar.gz Archive and Extract into /tmp
Or from Shell:

tar xvzf ~/Downloads/jdk-8*.tar.gz -C /tmp/

Open a Shell Terminal emulator window
Alt+Space > Type “kons” > Return
(Press “Enter” to Execute Commands)

In case first see: Terminal QuickStart Guide.

Relocate Java JDK 8.

sudo su

You will be prompted to Insert the SuperUser Password
If Got “User is Not in Sudoers file” then see: How to Enable sudo
Make a jvm Directory if Not already there with

if [ ! -d "/usr/lib/jvm" ]; then mkdir /usr/lib/jvm; fi

Set the root superUser as owner

sudo chown -R root:root /tmp/jdk1.8*

Reiterate the Execution Permission over the Java binaries

chmod -R +x /tmp/jdk1.8*/bin

Finally, Shift the Java contents with

mv /tmp/jdk1.8* /usr/lib/jvm/

Installing Oracle Java JDK 8
You can directly Copy & Paste the Commands into Terminal..

update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8*/bin/java 1065

update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8*/bin/javac 1065

update-alternatives --install /usr/bin/jar jar /usr/lib/jvm/jdk1.8*/bin/jar 1065

update-alternatives --install /usr/bin/javaws javaws /usr/lib/jvm/jdk1.8*/bin/javaws 1065

Checking or Setting the System Java Version in Use with

update-alternatives --config java

To Switch of Java Version Just Enter the Selection Number on First, Column. :)

Setting JAVA_HOME User Environment Variable (Optional).

su [myUserName]

Or simply:

exit

And Edit the Bash environment Configuration file

nano $HOME/.bashrc

Append:

export JAVA_HOME=/usr/lib/jvm/jdk1.8[uX]

Replace the [uX] Looking for the Installed Java 8 Version with:

ls /usr/lib/jvm/

Ctr+x to Save & Exit from nano Editor :)
Load New Bash Config:

bash

Test New Java JDK 8 Installation.

java -version