Android: implementing and running a listener on a socket

I am developing an Android application,

I need to make a session between the client (cell phone) and the web server (apache) and save this session to receive notifications from the server for that I can implement socket also make this socket listener to notify the client if the file is ready to download after receiving of this notification (file id) the client will download this file

so my question is, can this be implemented? the best solution is to use sockets or web service you can fill me some links or guides to help me implement this.

Thank you very much