private static String formatByteArray(final byte[] filePiece, final int maxLength) {
    final int length = filePiece.length;
    final int displayLength = Math.min(length, maxLength);
    final StringBuilder sb = new StringBuilder();
    sb.append("[");
    for (int i = 0; i < displayLength; i++) {
      sb.append(String.format("%02x", filePiece[i]));
      if (i < displayLength - 1) {
        sb.append(", ");
      }
    }
    if (length > maxLength) {
      sb.append("...");
    }
    sb.append("]");
    return sb.toString();
  }
The piece of the file content.
iotdb-client/service-rpc/src/main/java/org/apache/iotdb/rpc/subscription/payload/poll/FilePiecePayload.java