Those classes can call stored procedures or functions.
Those classes can be called BY stored procedures or functions.
You can call stored procedures and functions from server-side Java code.
So you can have a java app call a stored proc call a java class call a stored proc ...
Yes. Yes, this is why they call it Legacy.
or, if the modern job postings are indicative, FastAPI to PG to PY https://www.postgresql.org/docs/17/plpython-funcs.html
Those classes can call stored procedures or functions.
Those classes can be called BY stored procedures or functions.
You can call stored procedures and functions from server-side Java code.
So you can have a java app call a stored proc call a java class call a stored proc ...
Yes. Yes, this is why they call it Legacy.