问java.io.FileNotFoundException:此文件无法作为文件描述符打开；它可能已压缩

EN

@Override
public AssetFileDescriptor openAssetFile(final Uri uri, final String mode) throws FileNotFoundException
{
    final String assetPath = uri.getLastPathSegment();  // or whatever

    try
    {
        final boolean canBeReadDirectlyFromAssets = ... // if your asset going to be compressed?
        if (canBeReadDirectlyFromAssets)
        {
            return getContext().getAssets().openFd(assetPath);
        }
        else
        {
            final File cacheFile = new File(getContext().getCacheDir(), assetPath);
            cacheFile.getParentFile().mkdirs();
            copyToCacheFile(assetPath, cacheFile);
            return new AssetFileDescriptor(ParcelFileDescriptor.open(cacheFile, MODE_READ_ONLY), 0, -1);
        }
    }
    catch (FileNotFoundException ex)
    {
        throw ex;
    }
    catch (IOException ex)
    {
        throw new FileNotFoundException(ex.getMessage());
    }
}

private void copyToCacheFile(final String assetPath, final File cacheFile) throws IOException
{
    final InputStream inputStream = getContext().getAssets().open(assetPath, ACCESS_BUFFER);
    try
    {
        final FileOutputStream fileOutputStream = new FileOutputStream(cacheFile, false);
        try
        {
            //using Guava IO lib to copy the streams, but could also do it manually
            ByteStreams.copy(inputStream, fileOutputStream); 
        }
        finally
        {
            fileOutputStream.close();
        }
    }
    finally
    {
        inputStream.close();
    }
}