t.setOutputProperty(OutputKeys.INDENT, "yes"); // insert newlines
t.setOutputProperty(OutputKeys.METHOD, "xml");
t.setOutputProperty(OutputKeys.VERSION, "1.0");
t.setOutputProperty(OutputKeys.ENCODING, "utf-8");
t.setOutputProperty(OutputKeys.STANDALONE, "yes");
Source src = new DOMSource(doc);
File sysDir = new File(WebappHelper.getUserDataRoot(), SYSTEM_DIR); // destination is .../olatdata/system/catalog.xml
File f = new File(sysDir, XML_FILE);
File o = new File(sysDir, XML_FILE + ".old");
OutputStream os = new BufferedOutputStream(new FileOutputStream(o));
try {