install java in ubuntu 20.04
# Java in ubuntu
# first check if java is already installed or not using
java -version
# install openjdk (Java Development Kit)
sudo apt install default-jdk
# it will ask for confirmation...around 480 MB will be downloaded
# this will install both the latest jdk and jre of openjdk distribution
# check for java
java -version
#check for javac
javac -version
# If you only want to install jre and not jdk, just run
sudo apt install default-jre