What is the best way to position the caret at the end of a JTextField on focus?

By default, when a JTextField gains focus the caret is positioned at the beginning of the text. However, I think the better behavior is to position it at the end, or to select all the text, e.g. http://jsfiddle.net/Marcel/jvJzX/. What is a nice way to do this? Ideally, the solution would be applied globally to all JTextFields in the application.

Example of the default behavior (hit tab to focus the field):

public static void main(String[] args) {
    JTextField field = new JTextField("hello world!");
    JOptionPane.showMessageDialog(null, field);
}

Edit: To clarify, it would be nice if I didn't have to search through my app and change all the text fields.

Solution

Neither the actual behaviour nor the requirement are fully described:

when a JTextField gains focus the caret is positioned at the beginning of the text

that's not entirely true: when it gains focus by

clicking, the caret is placed at the mouse location
other means (tabbing, programmatic) it is placed at the position it had at the time focus was lost.

Consequently, the requirement:

the better behavior is to position it at the end, or to select all the text

needs a bit of thought for those cases to not detoriate usability, at least for the first users might be confused if a mouse gesture would be overruled. The second is arguable and probably OS/LAF dependent. Personally, I wouldn't touch the caret if its position is not at the start.

Technically, a solution to globally trigger changes of component state on focus changes is to register a PropertyChangeListener with the KeyboardFocusManager:

PropertyChangeListener pl = new PropertyChangeListener() {

    @Override
    public void propertyChange(PropertyChangeEvent evt) {
        if (!(evt.getNewValue() instanceof JTextField)) return;
        JTextField field = (JTextField) evt.getNewValue();
        // crude check to not overdo it
        int dot = field.getCaretPosition();
        if (dot == 0) {
            field.selectAll();
        }
    }
};
KeyboardFocusManager.getCurrentKeyboardFocusManager()
    .addPropertyChangeListener("permanentFocusOwner", pl);