---
title: "NCG Android SDK 2.19.0"
description: "Updated NcgEpubFile.open(String cID, String path) function:"
---
> For the complete documentation index, see [llms.txt](/llms.txt).

- **Updated** `**NcgEpubFile.open(String cID, String path)**` **function:**

  - Added `cID` (Content ID) parameter to the `NcgEpubFile.open()` function.

  - When the same Content ID is reused, internal file open and DRM info parsing are skipped, improving performance.

- **Added Multi-thread Support for** `**NcgEpubFile**`**:**

  - `NcgEpubFile` class now supports multi-threaded usage.

  - Each `NcgEpubFile` instance must be operated by a single thread — multiple threads reading from the same `open()` call are not supported.

- **Updated** `**NcgEpubFile.close()**` **call behavior:**

  - `close()` should no longer be called immediately after each `open()`. Instead, call `close()` only when all file operations are complete.

  - For contents sharing the same `cID`, use `open()` to open the next file without calling `close()` in between.

  - Example: When an EPUB file contains multiple internal files, call `open()` for each file as needed, and call `close()` only once when all files within the EPUB have been processed.