Some Apps need Java to work.
Most of them needs an actual JRE, which is also a much smaller installation-file than the full JDK.
The JRE has also its own directory at sourceforge: https://sourceforge.net/projects/portableapps/files/OpenJDK%20JRE%20Port...
But in the App directory I can only find the JDK version to download, not the JRE (or maybe I'm to blind to see it.)
Maybe the JRE version can be listed in the app directory as separate App, for easy downloading and installation?
It's called jPortable due to the trademark agreement with Oracle.
Sometimes, the impossible can become possible, if you're awesome!
I use an implementation of a Java JRE from here: Home Page: https://adoptium.net/
Download Page: https://adoptium.net/temurin/releases/
At the download page use the drop-down boxes to specify the download you want. If you want the JRE as a portable just download the appropriate zip package.
I use the portable implementation with LibreOffice and it works fine, no complaints.
The install size of the portable implementations are roughly as follows:
JRE x64 123MB — JDK x64 299MB
JRE x86 103MB — JDK x86 275MB
Use Portable Apps on both Flash Drive and HDD/SSD.