Can i create my own custom snaps in snaplogic?
does snap logic support Java to run my logic?
if it support and it requires extra packages how can we install?
not only java even in python or any another language ?
Yes, you can make your custom snaps in snapLogic.
The link shared by @dmiller is spot on, both of these have been mentioned in the initial snapLogic training and documentation that you can refer to by clicking ? button on any snap settings.