ODATA BDC and Front End Services handling issue

Hi,

I am new to odata, could you please anyone clarify the below points.

1.We used to call cl_gui_frontend_services=>directory_browse to select a folder but how to achieve this functionality in odata. who is going to handle it front end developers or odata developers. If we can achieve this please mention how to achieve.

2.Can we write BDC code in odata service, will it work?

3. How to download excel file which is uploaded from front end in odata