How to add Jar files to classpath?

Im having a hard time finding the .bashrc file that I would like to edit in order to not have to include writing out the .jar files i would like to use when i compile a .java file. Is there anyway someone could direct me in the proper direction for Dietpi? Im also using the Stretch image with openjdk 9

I found a way to add the path but, It does not seem to stick once I reboot. Any ideas ?