The current version of raspbian installs jdk-11 (hard float) and that is just fine, if you have more that one version of java installed you could use
update-alternatives tool to manage their use.
Then install JRuby see jruby.
jgem install picrate
Install samples, and configure
geany ide (for
picrate -i # or picrate --install
or for no geany configuration
picrate -i Samples # or picrate --install Samples
Install processing libraries
# picrate -i Sound not currently working picrate -i video # preferred over vanilla video for now
Creating Sketches from the GeanyIDE
See editors geany, for how to run sketches from a gui.
Running PiCrate sketch on RaspberryPI from geany editor