Custom Burp extension in Jython

Hi, I have a big problem with my custom burp extensions written in Python (To be precise - in Jython). It works perfectly unless I import any Java utility. None of IDEs can't understand Java libraries, I went through millions of tutorials and nothing works. Also Burp doesn't understand them. Does anybody here have experience in writing custom Burp Extensions and can help me to make it work?

burp cybersecurity extension