There is opportunity to use String.stripTrailing() method in java.desktop in SwingUtilities2 class.
Currently used method has the same logic:

    private static String trimTrailingSpaces(String s) {
        int i = s.length() - 1;
        while(i >= 0 && Character.isWhitespace(s.charAt(i))) {
            i--;
        }
        return s.substring(0, i + 1);
    }