Installing Oracle JDK 8 on Ubuntu

Download the Oracle JDK 8 tar file from http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
Extract the tar file: export PATH=$PATH:/usr/java/jdk1.5.0_07/bin export PATH=$PATH:/usr/java/jdk1.5.0_07/bin
	tar -xvzf jdk-8-linux-x64.tar.gz
Create jvm folder in /usr/lib, if jvm folder not exist
	sudo mkdir /usr/lib/jvm
Move extracted jdk 8 folder to this location:
	sudo mv jdk1.8.0 /usr/lib/jvm/jdk1.8.0
Install new java source in system:
	sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.8.0/bin/javac 1
	sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.8.0/bin/java 1
	sudo update-alternatives --install /usr/bin/javaws javaws /usr/lib/jvm/jdk1.8.0/bin/javaws 1
	OR THE FOLLOWING FOR JDK 1.8.0 update 71
	sudo update-alternatives --install /usr/bin/javac javac /usr/local/java/jvm/jdk1.8.0_71/bin/javac 1
	sudo update-alternatives --install /usr/bin/java java /usr/local/java/jvm/jdk1.8.0_71/bin/java 1
	sudo update-alternatives --install /usr/bin/javaws javaws /usr/local/java/jvm/jdk1.8.0_71/bin/javaws 1
Choose default java:
	sudo update-alternatives --config javac
	sudo update-alternatives --config java
	sudo update-alternatives --config javaws
Java version test:
	java -version

# java version "1.8.0"
# Java(TM) SE Runtime Environment (build 1.8.0-b132)
# Java HotSpot(TM) 64-Bit Server VM (build 25.0-b70, mixed mode)
OR THE FOLLOWING FOR JDK 1.8.0 update 71
# java version "1.8.0_71"
# Java(TM) SE Runtime Environment (build 1.8.0_71-b15)
# Java HotSpot(TM) 64-Bit Server VM (build 25.71-b15, mixed mode)

Verify the symlinks all point to the new java location:
	ls -la /etc/alternatives/java*
	OUTPUT
	#lrwxrwxrwx 1 root root 36 2016-01-23 08:01 /etc/alternatives/java -> /usr/local/java/jdk1.8.0_71/bin/java
	#lrwxrwxrwx 1 root root 37 2016-01-23 08:01 /etc/alternatives/javac -> /usr/local/java/jdk1.8.0_71/bin/javac
	#lrwxrwxrwx 1 root root 39 2015-1export PATH=$PATH:/usr/java/jdk1.5.0_07/bin export PATH=$PATH:/usr/java/jdk1.5.0_07/bin2-17 02:03 /etc/alternatives/javadoc -> /usr/local/java/jdk1.8.0_45/bin/javadoc
	#lrwxrwxrwx 1 root root 39 2015-11-25 22:30 /etc/alternatives/java_vm -> /usr/lib/jvm/java-6-sun/jre/bin/java_vm
	#lrwxrwxrwx 1 root root 38 2016-01-23 08:02 /etc/alternatives/javaws -> /usr/local/java/jdk1.8.0_71/bin/javaws

Enable Java plugin for Mozilla Firefox (even for Chrome)
# for 64-Bit jdk
	sudo ln -s /usr/lib/jvm/jdk1.8.0/jre/lib/amd64/libnpjp2.so /usr/lib/mozilla/plugins
	OR
	sudo ln -s /usr/local/java/jdk1.8.0_71/jre/lib/amd64/libnpjp2.so /usr/lib/mozilla/plugins
# for 32-Bit jdk
	sudo ln -s /usr/lib/jvm/jdk1.8.0/jre/lib/i386/libnpjp2.so /usr/lib/mozilla/plugins
JAVA_HOME configuration: Some tools require JAVA_HOME variable. You can set JAVA_HOME on Ubuntu either:
With /etc/environment:
	sudo gedit /etc/environment
# add the following line, save and exit
JAVA_HOME=/usr/lib/jvm/jdk1.8.0
Or in your home directory with .bashrc:
	sudo gedit .bashrc
# add the following lines, save and exit
	export JAVA_HOME=/usr/lib/jvm/jdk1.8.0
	export PATH=$JAVA_HOME/bin:$PATH