Android Background processing even after process has stopped explicitly by user (Long pressing home button and deleting all recent apps)

Question

I am newbie to android. I am creating file sharing application. When user1 asks to user2 for file, user2 will get notification and further upload and download process will execute.

Question: How can I implement such task which will keep track about some one has asked for file? I have created database in which entry will be done when someone asks for file. But how android device can constantly check that entry?

I want such mechanism which is used by gmail to check every time for email. When mail comes, it shows notification.

Please help me to create such a background processing. Any help appreciated. Thanks in advance.

Answer 1

I got an answer. I will have to use Google FCM push notification. I was unaware about that before. At last I found solution. Thanks for help..