Review

class Hex {
   /**
    * Hexadecimal representations of <code>data</code> with spaces between
    * individual bytes. Each string represents <code>columns</code> bytes,
    * except for the last one, which represents at most <code>columns</code>
    * bytes.
    *
    * @param data the byte array to represent.
    * @param columns the width of each line.
    * @param padWidth resulting strings will be padded to this length with
    *    spaces to the right.
    *
    * @return spaced hexadecimal representations of <code>data</code>.
    */
   private static String[] bytesToSpacedHexStrings(byte[] data, int columns,
                                           int padWidth) {
      byte[][] src = split(data,columns);
      String[] result = new String[src.length];
      for (int j = 0; j < src.length; j++) {
         result[j] = bytesToSpacedHexString(src[j]);
         result[j] = pad(result[j],padWidth,' ',RIGHT);
      }
      return result;
   }

}