Servlets :: Event Stream Does Not Stop After JSP Exits

I have a servlet which sends HTML5 server sent events to the jsp client. The servlet sends data to the client every one second. The jsp client instantiates a new eventsource and recieves the data. When the window is about to close, the jsp client closes eventsource at the "beforeunload" event (shown in the code below).

However, I have noticed that even after the client closes the eventsource and the browser exits, the server continues sending data. As far as the documentation on eventsource goes, using eventsource.close() is enough to stop client from reconnecting to the server and the server will stop sending any further push notifications.

Why the server does not stop sending push notifications even after eventsource.close() and the browser exit? Do I write any other piece of code to notify the server to stop sending data once client exits?

Pasted below are the servlet (server ) code and the client code.

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;

[Code] .....