Well, I have found decision, maybe it will useful for someone:
String n =
rootElement.getElementsByTagName("ID").item(0).getNodeName();
String v =
rootElement.getElementsByTagName("ID").item(0).getChildNodes().item(0).getNodeValue();
-----
n=ID
v=399999
XMLParser in GWT has strange behavior, it regards list-node value as
one more node and requires getting childe nodes for it...