Question

I hava an app on JSF where I upload a file. Very basic. The question is, is there a way to launch (or keep executing) another java program when I reach the last page of my app? That is:

UploadFile.xhtml -> receiveFile.java -> Thanks.xhtml (user will close this the browser) -> another program make some processing on the recently uploaded file (even if user shutsdown the PC)

I thought using a daemon program that keeps checking if a new file arrived, but I want to know if there’s a way to keep executing things even if the user closes the browser.

Thanks.

Answer 1

Certainly the best way to do this is to have a scheduler that will look for certain files every x time interval and do something with it within a thread.

Advice, make sure you shut down the scheduler on context unload. Here is an example on how to use a SchedulerService.

You would want to do something like in a context listener.

    ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
    Runnable handler = new Runnable() {
           public void run() { 
                // handle file
           }
    };
    scheduler.scheduleAtFixedRate(handler, 10, 10, SECONDS);