Can't compile Java code?

Question

Java

Good evening everyone!
I can’t compile the code for this program: https://github.com/kin3tik/Verifier
There are suspicions that the 2017 compiler can no longer compile the 2012 code. I must say right away that I am not a programmer) If there are solutions to this problem, I will be glad for any explanations .
Thank you in advance!

Answer 1

Java is backwards compatible, future versions collect deprecated code

Answer 2

You need to include the swing library. Use maven