try {
    spinner.commitEdit();
}
catch (ParseException pe) {{
    // Edited value is invalid, spinner.getValue() will return
    // the last valid value, you could revert the spinner to show that:
    JComponent editor = spinner.getEditor()
    if (editor instanceof DefaultEditor) {
        ((DefaultEditor)editor).getTextField().setValue(spinner.getValue();
    }
    // reset the value to some known value:
    spinner.setValue(fallbackValue);
    // or treat the last valid value as the current, in which
    // case you don't need to do anything.
}
return spinner.getValue();