Method copy

app/src/main/java/androidx/room/FileUtil.java:47–67

Copies data from the input channel to the output file channel. @param input the input channel to copy. @param output the output channel to copy. @throws IOException if there is an I/O error.

(@NonNull ReadableByteChannel input, @NonNull FileChannel output)

     * @throws IOException if there is an I/O error.
     */
    @SuppressLint("LambdaLast")
    public static void copy(@NonNull ReadableByteChannel input, @NonNull FileChannel output)
            throws IOException {
        try {
            if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) {
                output.transferFrom(input, 0, Long.MAX_VALUE);
            } else {
                InputStream inputStream = Channels.newInputStream(input);
                OutputStream outputStream = Channels.newOutputStream(output);
                int length;
                byte[] buffer = new byte[1024 * 4];
                while ((length = inputStream.read(buffer)) > 0) {
                    outputStream.write(buffer, 0, length);
                }
            }
            output.force(false);
        } finally {
            input.close();
            output.close();
        }
    }

    private FileUtil() {
    }