installing openJDK

Ubuntu flavored distributions have the openjdk packages already on its own repos.

open a terminal like:

• KDE’s Konsole
• GNOME’s Terminal

# for the java openjdk 14 you need to run
you@host:~$ sudo apt install openjdk-14-jdk

wait for the installation to complete…

# confirm that you have the Openjdk java runtime installed correctly by running the java command 
# and checking you get a similar result as below
user@hostname:~$ java -version

openjdk version "14.0.2" 2020-07-14
OpenJDK Runtime Environment (build 14.0.2+12-Ubuntu-120.04)
OpenJDK 64-Bit Server VM (build 14.0.2+12-Ubuntu-120.04, mixed mode, sharing)

# confirm that you have the Openjdk java compiler installed correctly by running the javac command
# and checking you get a similar result as below
user@hostname:~$ javac -version

javac 14.0.2

if your system does not recognize the javac command most likely you installed the jre instead of the jdk, review the steps above and make sure you executed them properly.