public class Main {

public static void main(String args[]) throws Exception {
StreamSource source = new StreamSource(args[0]);
StreamSource stylesource = new StreamSource(args[1]);

TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer(stylesource);

StreamResult result = new StreamResult(System.out);
transformer.transform(source, result);
}
}

=========================================================

When I try to run the XSLT that we ended up with back in February
2023, I am getting an error:

"[root@dlwoas01 jl]# java Main X.xml X.xsl
ERROR: 'Could not compile stylesheet'
FATAL ERROR: 'Error checking type of the expression 'funcall(tokenize,
[step("self", -1), literal-expr(:)])'.'
:Error checking type of the expression 'funcall(tokenize,
[step("self", -1), literal-expr(:)])'.
"
I suspect/guess that the problem is that the Java 1.8 only supports
XSLT 1.0, but I don't know if it is allowable to ask about this type
of thing here in this list, so I wanted to ask that first?

You can use Saxon HE (currently supported latest versions are 11.5 and
12.3 (e.g.
https://github.com/Saxonica/Saxon-HE/releases/tag/SaxonHE12-3, also on
Maven) from Saxonica to have XSLT 3.0 (which supports all of XSLT 2, of
course) with Java. Putting Saxon on the classpath for your code above
should suffice.