code: public static ARCReader get(final URL arcUrl, final long offset)
      throws IOException {
          return (ARCReader)ARCReaderFactory.factory.getArchiveReader(arcUrl,
              offset);
      }
docs: Get an ARCReader aligned at <code>offset</code>. This version of get
  will not bring the ARC local but will try to stream across the net making
  an HTTP 1.1 Range request on remote http server (RFC1435 Section 14.35).
  
  @param arcUrl HTTP URL for an ARC (All ARCs considered remote).
  @param offset Offset into ARC at which to start fetching.
  @return An ARCReader aligned at offset.
  @throws IOException