StringBuffer buffer = new StringBuffer(sz);
    public static String deleteWhitespace(String str) {        if (str == null) {            return null;        }        StringBuffer buffer = new StringBuffer();        int sz = str.length();        for (int i = 0; i < sz; i++) {            if (!Character.isWhitespace(str.charAt(i))) {                buffer.append(str.charAt(i));            }        }        return buffer.toString();    }