I have a case like getting an XML and convert the XML elements to document object and getting the element values and attributes which i have been created already
Her
DocumentBuilder db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document document = db.parse(new ByteArrayInputStream(xmlString.getBytes("UTF-8"))); //remove the parameter UTF-8 if you don't want to specify the Encoding type.
this works well for me even though the XML structure is complex.
And please make sure your xmlString is valid for XML, notice the escape character should be added "\" at the front.
The main problem might not come from the attributes.