Use Terminal or CMD or other command line interface
Windows, Mac, Linux = OK
Android, IOS = very awkward or impossible
SSH = ok for this program but won't work in the future (or can use X Windows)
Work in pairs, pair with someone who has laptop in class
Make sure java is running on your machine
Then, download and run one of the Java shape programs from the lecture examples and/or write a short command line Hello World program of your own.
Modify the program to try out some Java features you think might be useful to you (like inheritance and polymorphism).