go to https://processing.org/ to download linux version
Move the extarct file to /opt
/opt/processing
sudo su -c “ln -s /opt/processing-3.0.2/processing /usr/local/bin/processing”a
cd /usr/share/applications/
sudo gedit /usr/share/applications/processing.desktop
OR
sudo vim /usr/share/applications/processing.desktop
Copy this
[Desktop Entry]
Version=2.1
Name=Processing
Comment=Processing Rocks
Exec=processing
Icon=/opt/processing/lib/icons/pde-256.png
Terminal=false
Type=Application
Categories=AudioVideo;Video;Graphics;
DONE! for check
cat processing.desktop