I created a DoubleFormattedTextField class shows below and
new DoubleFormattedTextField("#.###", 0.0, 2.5);

I expect it commit when I enter between 0.0 and 2.5 everything else
less than or great than or not double such as "a string" should revert.
But it doesn't work that way. I entered -1.2, 3.5 or "hello world", they
all committed.
Can anyone out there tell me what I have missed?

Thank Q very much!

class DoubleFormattedTextField extends JFormattedTextField {
    private static final long serialVersionUID = 1L;

    private double minimum;
        private double maximum;

    public DoubleFormattedTextField(String format, double minimum, double
maximum) {
        super(new DecimalFormat(format));
        this.minimum = minimum;
        this.maximum = maximum;

        NumberFormat doubleFormat = DecimalFormat.getNumberInstance();
        doubleFormat.setMinimumFractionDigits(3);
        doubleFormat.setMinimumIntegerDigits(1);
       
       
        NumberFormatter doubleFormatter = new NumberFormatter(doubleFormat);
        doubleFormatter.setFormat(doubleFormat);
        doubleFormatter.setMinimum(new Double(this.minimum));
        doubleFormatter.setMaximum(new Double(this.maximum));
       
        setFormatterFactory(new DefaultFormatterFactory(doubleFormatter));
        setFocusLostBehavior(JFormattedTextField.COMMIT_OR_REVERT);

    }
}