Depending on what sort of document you're looking for, you might like either the JEP: https://openjdk.org/jeps/254
or Shipilev's slides (pdf warning): https://shipilev.net/talks/jfokus-Feb2016-lord-of-the-string...
Shipilev's website (https://shipilev.net/#lord-of-the-strings), and links from the JEP above to other JEPS, are both good places to find further reading.
(I think I saw a feature article about the implementation of the string compression feature, but I'm not sure who wrote it or where it was, or if I'm thinking about something else. Actually I think it might've been https://shipilev.net/blog/2015/black-magic-method-dispatch/, despite the title.)
Shipilev's website looks like a fascinating resource. I appreciate the pointer!
I would, but unfortunately I got a NullPointerException.
I suggest you try Rust instead; its borrow checker will ensure you can't share pointers in an unsafe manner.
You can't share "pointers" in an unsafe manner in Java. Even data races are completely memory safe.