I am trying to pass params to a xsl stylesheet from a Java application. It falls over with the following error
"org.xml.sax.SAXParseException: Content is not allowed in prolog."

Usually this means there is whitespace, in often a line feed before the
XML declaration, i.e. before...

<?xml version="1.0" encoding="UTF-8"?>

  ^^^ ...here
Check this first.