Saving a bitmap in android but it's a black picture

Question

I am building an Android app and of its jobs is to save a picture out of a canvas. The screenshoting part works great, the problem is when I save the photo. When I try to look at the photo the app saved, I get a black screen.

My code for saving is:

private int saveToInternalStorage(Bitmap bitmapImage) {
        String path = Environment.getExternalStorageDirectory().toString();
        OutputStream fOutputStream = null;
        File file = new File(path + "/drawings/");
        if (!file.exists()) {
            file.mkdirs();
        }
        file = new File(path + "/drawings/", "drawing.png");

        try {
            fOutputStream = new FileOutputStream(file);

            bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fOutputStream);

            fOutputStream.flush();
            fOutputStream.close();

            MediaStore.Images.Media.insertImage(getContentResolver(), file.getAbsolutePath(), file.getName(), file.getName());
            return 0;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            Toast.makeText(this, "Save Failed, Error 1", Toast.LENGTH_SHORT).show();
            return -1;
        } catch (IOException e) {
            e.printStackTrace();
            Toast.makeText(this, "Save Failed, Error 2", Toast.LENGTH_SHORT).show();
            return -1;
        }
    }

Plus, the photo doesn't appear in my gallery.

What can I do in order to solve this?

Thanks, Iliya.