fixed critical issue in copying large files

[l3utterfly]

Critical issue in android for copying large files: previous version downloads the large file but does not copy anything over 2GB.

Sorry! This PR fixes it.

[kesha-antonov]

Is it working on android 7.0?

[kesha-antonov]

https://developer.android.com/reference/java/nio/file/package-summary

Added in API level 26
java.nio.file

I previously added this API but changed to FileChannel because we need to support android 7.0+ (api 24+)

[l3utterfly]

Hmm.. my app has min version 26 so this was not a problem.

How about this code?

private static void moveFile(File src, File dst) throws IOException {
    FileChannel inChannel = new FileInputStream(src).getChannel();
    FileChannel outChannel = new FileOutputStream(dst).getChannel();
    try {
        long bytesTransferred = 0;
        long totalBytes = inChannel.size();
        while (bytesTransferred < totalBytes) {
            long remainingBytes = totalBytes - bytesTransferred;
            long chunkSize = Math.min(remainingBytes, Integer.MAX_VALUE);
            long transferredBytes = inChannel.transferTo(bytesTransferred, chunkSize, outChannel);
            bytesTransferred += transferredBytes;
        }
        src.delete();
    } finally {
        if (inChannel != null)
            inChannel.close();
        if (outChannel != null)
            outChannel.close();
    }
}

(untested, but should work). The main problem with the previous code is that transferTo takes an Int, which cannot go past 2GB

[kesha-antonov]

Could you test in android emulator with api 24?

I can do it also but on Wednesday.

[Prashant13Pawar]

Not able to download files above 1GB . Please provide fix for this

[l3utterfly]

Did you try the code in the PR? I tested it and it works for files over 4GB with no problems

[Prashant13Pawar]

I tried code from PR still same issue

[l3utterfly]

Hmm.. not sure, will take a look later. The code works fine, and it is already in production, so not sure what's wrong with your version