"read configuration entirely from [an] XML file (without need to create [a] class)?"
...the answer is yes! Being able to generate UIs from a variety of sources, including dynamic ones such as rule engines or database entries, is a core capability of Metawidget. I've put together a simple example that uses an XmlInspector to configure the UI, and a custom MapProcessor to store the data. No Classes or JavaBeans are used at all.
You can download the example here.
Telefonica, one of the largest telecommunications companies in the world, used this same approach for the Spanish National Health System. You can read more about this large-scale deployment in our whitepaper.