Apologies, I was reminded of an urgent breakfast appointment.
The item that Zbe refers to can be found here:
Here is the original:
This part is relevant to you:
So, something like:
sudo pacman -S jre-openjdk
or
sudo pacman -Syu jre-openjdk
(or substitute for jre-openjdk-headless depending on which you wish to keep)
The resolution itself is fairly straightforward, however there may be additional unforeseen complications depending on your particular environment.
Cheers.