Upload zip file and unzip it

I need to periodically update the assets (pictures) in my app, from a local zip file if possible.
I'm trying to use activity starter (action = android.intent.action.GET_CONTENT; DataType = application/zip).
I also want to unzip this file with this extension:
and in the end, i need to store and save each picture in the zip as part of my asset.
Anyone can help? thanks.