How to return from a process to a frontend backend process?

Question

I need load 10.000 rows in my database google cloud sql using AppEngine with Java. For this case, i use a proccess using backend, but i want advertise to user, how rows was wrong load? But, i don't know as send a message from my backend proccess to my front to show a message to screen.

Regards.

Answer 1

Maybe you don't need to send callback (from backend to front-end). Maybe you should make the front-end poll to see when these results are ready at the back-end side. Maybe through some JS/Ajax code which keeps polling on the background and once the results are ready, pulls them and displays them in the designated area of the page. I assume your front-end is a web page.