Switches between the installed java versions for development on a linux (Ubuntu) machine.
If you haven't installed the java versions in the same folder, use j6.sh, j7.sh, j8.sh ... j11.sh

if they are already installed in the same the same folder, use:

$ bash javaswitcher.sh 6
$ bash javaswitcher.sh 7
$ bash javaswitcher.sh 8
...
$ bash javaswitcher.sh 11

on Arch linux the system already has a built in way to change between the settings:

archlinux-java get

will return the current version, for expample: java-8-openjdk

you can list all versions with:

archlinux-java status

you can change between the versions with: JDK 8:

sudo archlinux-java set java-8-openjdk

or
JDK 11:

sudo archlinux-java set java-11-openjdk