On 18/07/17 18:07, Campbell, Lance wrote: > Also if tomcat is shut down and a thread is running how does tomcat > communicate with my software to end a thread?
It can't. The thread will either just stop if it is a Daemon thread or the Java process won't exit until your thread does. > Is this where you were referring to the servlet context listener? Yes. That is a good way to start/stop threads. > > -----Original Message----- > From: Campbell, Lance [mailto:la...@illinois.edu] > Sent: Tuesday, July 18, 2017 12:00 PM > To: Tomcat Users List <users@tomcat.apache.org> > Subject: RE: run thread from servlet > > Basically I have batch jobs that I need to run on many different web > applications. The batch jobs call servlets that then create threads to do > whatever task I need done behind the scenes. The servlets immediately return > a message after starting the batch threaded job. However my understanding > is that there can be issues with Tomcat detecting memory leaks if you have a > thread spawned by a servlet. So I was wondering if there was a better way to > trigger a thread. Memory leaks are likely because the Thread will almost certainly load classes from the web application. A (possibly single threaded) Executor started and stopped via a ServletContextListener is the solution that springs to mind. Mark > > -----Original Message----- > From: Pradip Bhattacharya [mailto:pradip.bhattacha...@gmail.com] > Sent: Tuesday, July 18, 2017 9:10 AM > To: Tomcat Users List <users@tomcat.apache.org> > Subject: Re: run thread from servlet > > Hello, > I hope I understood the requirement correctly. I believe you can start > EmailProcess thread by the context listener. This thread can wait on an > object. And the servlet can enque the data in a concurrent queue, and then > notify the object, on which EmailProcess thread is waiting. > Is this EmailProcess is an asynchronous service to send emails ? > Regards > Pradip.B > > On Jul 18, 2017 7:27 PM, "Campbell, Lance" <la...@illinois.edu> wrote: > > Tomcat 8.0.x > Question: > I am wanting to know the proper way to start a thread from a servlet. > > Use Case: > A batch process will call a URL that is a servlet. The servlet will call a > processes that will trigger a thread to run to do a particular job. The > thread will run for a while. The servlet will not wait on the thread to > finish running. Also the thread that is started is running a processes that > requires there to only be one of these processes running at any given time. > > What I have done: > I created a class I call EmailProcess. I have a static Boolean flag in the > class called isWorking that indicates if the process is running. The class > extends Runnable. The class also has a static method to start the thread if > isWorking flag is false. I have a servlet that will call the static method > in EmailProcess to start the thread if possible. > > Note: If the Tomcat container decides to clean up the servlet that is called > that triggers the thread I don't want it to mess with the thread. I want it > to keep on running. > > Thanks for your advice. > > Lance > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
