code: public static final String characterPad(final String s, final int fieldLength, final char padChar,
        final boolean postpend) {
      final char[] chArr = s.toCharArray();
      final int sLen = chArr.length;
      if (sLen < fieldLength) {
        final char[] out = new char[fieldLength];
        final int blanks = fieldLength - sLen;
  
        if (postpend) {
          for (int i = 0; i < sLen; i++) {
            out[i] = chArr[i];
          }
          for (int i = sLen; i < fieldLength; i++) {
            out[i] = padChar;
          }
        } else { //prepend
          for (int i = 0; i < blanks; i++) {
            out[i] = padChar;
          }
          for (int i = blanks; i < fieldLength; i++) {
            out[i] = chArr[i - blanks];
          }
        }
  
        return String.valueOf(out);
      }
      return s;
    }
docs: Prepend or postpend the given string with the given character to fill the given field length.
  If the given string is equal or greater than the given field length, it will be returned
  without modification.
  @param s the given string
  @param fieldLength the desired field length
  @param padChar the desired pad character
  @param postpend if true append the pacCharacters to the end of the string.
  @return prepended or postpended given string with the given character to fill the given field
  length.