code: public static byte[] getMD5(byte[] src) {
          assert src != null;
          try {
              return MessageDigest.getInstance("MD5").digest(src);
          } catch (NoSuchAlgorithmException ex) {
              throw new IllegalArgumentException("Missing 'MD5' algorithm", ex);
          }
      }
docs: Compute the MD5 of the given byte[] array. If the MD5 algorithm is not available
  from the MessageDigest registry, an IllegalArgumentException will be thrown.
  
  @param  src  Binary value to compute the MD5 digest for. Can be empty but not null.
  @return      16-byte MD5 digest value.