There's no need to re-invent things. Consider using SharedPreferences.
If you still want to use your XML-format and want to read it the proper way, here's something that will get you started:
InputStream is = ...
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(is);
doc.getDocumentElement().normalize();
NodeList myTags = doc.getElementsByTagName("your_xml_tag");
I can also highly recommend the XML/JSON-library Jackson . It can read and save complete objects using only a few lines of code.