How to Install JAVA JDK 12 in Ubuntu Linux (19.04, 18.04), Debian and Linux Mint
How to Install JAVA JDK 12 in Ubuntu Linux (19.04, 18.04), Debian and Linux Mint using APT
sudo add-apt-repository ppa:linuxuprising/java
sudo apt update
sudo apt install oracle-java12-installer
java -version
sudo update-alternatives --config java
sudo vim /etc/environment
JAVA_HOME=/usr/lib/jvm/java-12-oracle
source /etc/environment
echo $JAVA_HOME