A DESCRIPTION OF THE REQUEST :
At least standard plain text controls on Windows seem to have in-built, out-of-the-box support for Undo [Ctrl+Z]. See JGuru (http://www.jguru.com/faq/view.jsp?EID=11398): "I need for undo with group operations like in win32 edit controls. Is exists some sample of algorithm defines what is operation was begin and end for undo block?"

There have been some developments in this field: "Add an undo/redo function to your Java apps with Swing"
http://www.javaworld.com/javaworld/jw-06-1998/jw-06-undoredo.html

We have special section in Tutorial: "Implementing Undo and Redo" http://java.sun.com/docs/books/tutorial/uiswing/components/generaltext.html#undo

However, working "Ctrl+Z" is what at least Windows users expect working by default.

JUSTIFICATION :
This is about usability of Swing and probably about its fidelity.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Working "Ctrl+Z" is what at least Windows users expect working by default.
ACTUAL -
"Ctrl+Z" is not working out of the box.