Seems like it doesn't support records: https://javafiddle.leaningtech.com/#E4Uwxg9sAmAEAKECWA7ALgCl...

"record" is a Java 14+ feature. CheerpJ currently supports Java 8 only, but the 3.0 is designed to be scalable to modern Java versions.

Locally:

  exabrial@galactus:~$ jshell
  |  Welcome to JShell -- Version 17.0.6
  |  For an introduction type: /help intro

  jshell> System.out.println("HelloWorld!");
  HelloWorld!
  
  jshell> /exit
  |  Goodbye

Related ongoing thread:

CheerpJ 3.0: a JVM replacement in HTML5 and WASM to run Java on modern browsers - https://news.ycombinator.com/item?id=35873552 - May 2023 (121 comments)

There is also IJava (https://github.com/SpencerPark/IJava) -- a nice Jupyter Java kernel. Perfect for a lot of small Java programs for learning and teaching.

how do you bootstrap all the downloads from your ant/mvn/gradle to run anything besides hello world?