There are cases where we want to show users status of a long term process which has been started on the server. To achieve that we usually use a progress bar. I want to expose the implementation of the progress bar with using Server-sent events (more ways look at page). Server-sent events (SSE) is a technology where a client side automaticly receives data from a server via HTTP connection. It is enough to monitor a status of a process and to update our progess bar.
To build the application I use Spring MVC. Scince 4.2 version the SseEmmiter class has been introduced. This class makes more easier using of the Server-sent events with Spring.