How do I parse XML with german umlauts in ! names !?

I try to parse XML in java by

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(new ByteArrayInputStream(msg.getBytes("UTF-8")));

Everything seems to be ok, also

<data>äöü</data>

is parsed correctly (esp. concerning the german umlauts).

But when I try to parse

<däta>xxx</däta>

the parser throws an exception, names with umlauts in it seem to not work.

What to do?