What is the difference between localname and qname?

The qualified name includes both the namespace prefix and the local name: att1 and foo:att2.

Sample XML

<root     xmlns="http://www.example.com/DEFAULT"     att1="Hello"     xmlns:foo="http://www.example.com/FOO"     foo:att2="World"/>

Java Code:

att1

Attributes without a namespace prefix do not pick up the default namespace. This means while the namespace for the root element is "http://www.example.com/DEFAULT", the namespace for the att1 attribute is "".

int att1Index = attributes.getIndex("", "att1");attributes.getLocalName(att1Index);  // returns "att1"attributes.getQName(att1Index);  // returns "att1"attributes.getURI(att1Index);  // returns ""

att2

int att2Index = attributes.getIndex("http://www.example.com/FOO", "att2");attributes.getLocalName(att2Index);  // returns "att2"attributes.getQName(att2Index);  // returns "foo:att2"attributes.getURI(att2Index);  // returns "http://www.example.com/FOO"

Generally speaking, localname is the local name, meaning inside the namespace. qname, or qualified name, is the full name (including namespace). For example, <a:b …> will have a localname b, but a qname a:b.

This is however very general, and settings-dependant. Take a look at the example at the end of this page for a more thorough example: example

By default, an XML reader will report a Namespace URI and a localName for every element that belongs in a namespace, in both the start and end handler.

Consider the following example:

  <html:hr xmlns:html="http://www.w3.org/1999/xhtml"/>

With the default SAX2 Namespace processing, the XML reader would report a start and end element event with the Namespace URI http://www.w3.org/1999/xhtml and the localName hr. Most XMLReader implementations also report the original qName html:hr, but that parameter might simply be an empty string (except for elements that aren't in a namespace).

http://www.saxproject.org/namespaces.html