On the SAX handlers' function, 3 element name present: 

void startElement(String uri,
                  String localName,
                  String qName,
                  Attributes atts)
                  throws SAXException

For example, when <foobar:test xmlns:foobar="http://example.com/foobar"> tag is seeked, SAX call startElement function with following parameters:

uri "http://example.com/foobar"
localName "test"
qName "foobar:test"

When handling the Namespaceless XML documents, only qName seems to be used. But old Java Runtime such as Android 1.5(?), only localName seems to be used.

J2SE 6 Android 2.2 Android 1.5
uri "" "" ""
localName "" "" "test"
qName "test" "test" ""

Sourcecode for Android 2.2/1.5 is as following: 

public void testSAX() throws Exception {
    final TextView tv = new TextView(this);

    ByteArrayInputStream input = new ByteArrayInputStream("<test></test>".getBytes());

    SAXParserFactory factory = SAXParserFactory.newInstance();
    SAXParser parser = factory.newSAXParser();
    parser.parse(input, new DefaultHandler() {
        @Override
        public void startElement(String uri, String localName,
                String qName, Attributes attributes) throws SAXException {
            System.out.println("uri: " + uri);
            System.out.println("localName: " + localName);
            System.out.println("qName: " + qName);

            tv.setText(
                "uri: " + uri + "\n" +
                "localName: " + localName + "\n" +
                "test: " + qName
            );

            super.startElement(uri, localName, qName, attributes);
        }
    });

    setContentView(tv);
}