[Ubuntu] Install Java 8 (JDK 8) on Ubuntu

Step 1: Install Java 8 (JDK 8)

$ sudo add-apt-repository ppa:webupd8team/java
$ sudo apt-get update
$ sudo apt-get install oracle-java8-installer

Step 2: Verify the Java version

$ java -version

java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)

Step 3: Generate the default variables

$ sudo apt-get install oracle-java8-set-default