Android: get real filepath from uri without copying to filestream

Question

I am creating an app that allows the user to upload multiple files to my server and I am doing the uploading with the "Fast Android Networking" Library, so I will need to provide File Objects to upload the files and can not use the Uri's I get from the filechooser. Currently I'm getting an InputStream from a Uri and copy it into a File.

public static void copyInputStreamToFile(InputStream inputStream,
                                         File file) throws IOException {
    try (FileOutputStream outputStream = new FileOutputStream(file, false)) {
        int read;
        byte[] bytes = new byte[8192];
        while ((read = inputStream.read(bytes)) != -1) {
            outputStream.write(bytes, 0, read);
        }
    }
}

This though, will get any device to lag pretty fast and I'd like to avoid this. I searched everywhere but couldn't find a method for converting a Uri to a File object, that works for me. If anyone knows a way to directly upload from uri, that would also work for me.