Install Oracle Java in Ubuntu via terminal using PPA

- Launch Terminal and type the following command

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update

sudo apt-get install oracle-java8-installer

When there are multiple Java installations on your System, the Java version to use as default can be chosen. To do this, execute the following command.

sudo update-alternatives --config java
sudo update-alternatives --config javac
sudo update-alternatives --config javaws

Edit - Manual Java Installation

Download oracle jdk

http://www.oracle.com/technetwork/java/javase/downloads/index.html

Extract zip into desired folder

 e.g  /usr/local/  after extract /usr/local/jdk1.8.0_65

Setup

sudo update-alternatives --install  /usr/bin/java java /usr/local/jdk1.8.0_65/bin/java 1
sudo update-alternatives --install  /usr/bin/javac javac /usr/local/jdk1.8.0_65/bin/javac 1
sudo update-alternatives --install  /usr/bin/javaws javaws /usr/local/jdk1.8.0_65/bin/javaws 1

sudo update-alternatives --set  java /usr/local/jdk1.8.0_65/bin/java
sudo update-alternatives --set  javac /usr/local/jdk1.8.0_65/bin/javac
sudo update-alternatives --set  javaws /usr/local/jdk1.8.0_65/bin/javaws

Edit /etc/environment set JAVA_HOME path for external applications like Eclipse and Idea

For more information, Please clicked on the link below

http://stackoverflow.com/questions/25289482/installing-jdk8-on-ubuntu-unable-to-locate-package-update-doesnt-fix