How to install Oracle Java JDK on ubuntu 18 and set JAVA_HOME
This blog post will show step by step procedure to install Oracle java on Ubuntu using PPA.
Step 1: Open terminal (Ctrl + Alt + T OR Ctrl + T)
Step 2: Copy and paste the following command in terminal.
For Java 8
sudo add-apt-repository ppa:webupd8team/java For Java 11
sudo add-apt-repository ppa:linuxuprising/java
Step 3: Update the packages using following command
sudo apt update
Step 4: Download and install java installer
For Java 8
sudo apt install oracle-java8-installerFor Java11
sudo apt install oracle-java11-installer 
Step 5: To set Default Java version
For Java 8
sudo apt install oracle-java8-set-default For Java11
sudo apt install oracle-java11-set-default 
This will complete your java installation, you can verify your installation with following command
java -version
Bonus:
To change default version of java
sudo update-alternatives --config java
Setting JAVA_HOME
sudo nano /etc/environment
paste
JAVA_HOME="/usr/lib/jvm/java-8-Oracle/jre/bin"
