Starting threads in background?

Question

I am trying to address the issue where I have a somewhat
          time-consuming server-side operation, and I don't want the
          browser to time out, etc. So, I want to use a the html
          meta-refresh capability to keep the browser happy,
          and possibly send it some percent completed status info, etc.
          But to do this, it seems like I need to be able to start another
          thread on the server which will do the work, which the
          session thread can monitor, etc.
          Is there a certain way within weblogic that threads should be
          created etc., or is it allowed at all. I know that it is not
          allowed to start new threads within EJB code. What about
          within JSP's and JavaBeans?
          Thanks,
          Jason
          

Answer 1

You can just redirect using the response object, however sometimes you may
          want to do some fancier stuff with JavaScript, that is all I meant.
          > I am not clear on how you are able to detect when "processing..."
          > is completed. Do you use a meta refresh to spin until the
          > processing is done on the server side, and then redirect?
          Basically, yes. There are really two things to do:
          1) Displaying status of processing (not started, in progress, done)
          2) Refreshing if not done
          For example, if you identify the task as 1752324, your URL might be:
          http://myco.com/myapp/showstatus-1752324.proc
          Or:
          http://myco.com/myapp/showstatus?id=1752324
          The point is that the same URL could show:
          "Has not started yet"
          Then:
          "Is in phase 1"
          Then:
          "Is in phase 2"
          Then:
          "Is finished"
          And if the user refreshes the page in the browser or saves off the URL and
          visits it later or whatever, the process itself will not be repeated, just
          the status will be displayed
          Cameron Purdy
          [email protected]
          http://www.tangosol.com
          WebLogic Consulting Available
          "Jason Rosenberg" <[email protected]> wrote in message
          news:[email protected]...
          > Cameron,
          >
          > It seems like your response below is something you like to cut and
          > paste and post repeatedly...But can you augment it a little to explain
          > the second part of step 3, the "uses javascript to redirect" part?
          >
          > I am not clear on how you are able to detect when "processing..."
          > is completed. Do you use a meta refresh to spin until the
          > processing is done on the server side, and then redirect?
          >
          > Or what?
          >
          > I am not that familiar yet with JavaScript, does it have built in
          > functionality to do this? I am guessing not, since it is entirely
          > client-side....
          >
          > Jason
          >
          >
          > "Cameron Purdy" <[email protected]> wrote in message
          > news:[email protected]...
          > > 1) The work to be done is assigned a uid or something similar to
          prevent
          > it
          > > from being done twice
          > > 2) The user presses the button which passes the uid in a hidden field
          > (for
          > > example)
          > > 3) The serlvet responds by kicking off the big process with jms and
          sends
          > > back a page that displays a "processing..." message and uses javascript
          to
          > > redirect (with a place to click just in case javascript is turned off)
          > > 4) The url redirected to includes the uid to identify the process for
          > which
          > > the result is desired
          > > 5) When the process is completed, the information is placed in some
          known
          > > location (e.g. HttpSession or database) and the pending request to find
          > the
          > > result can return the result
          > >
          > > --
          > >
          > > Cameron Purdy
          > > [email protected]
          > > http://www.tangosol.com
          > > WebLogic Consulting Available
          > >
          > >
          > > "Jason Rosenberg" <[email protected]> wrote in message
          > > news:[email protected]...
          > > > I am trying to address the issue where I have a somewhat
          > > > time-consuming server-side operation, and I don't want the
          > > > browser to time out, etc. So, I want to use a the html
          > > > meta-refresh capability to keep the browser happy,
          > > > and possibly send it some percent completed status info, etc.
          > > >
          > > > But to do this, it seems like I need to be able to start another
          > > > thread on the server which will do the work, which the
          > > > session thread can monitor, etc.
          > > >
          > > > Is there a certain way within weblogic that threads should be
          > > > created etc., or is it allowed at all. I know that it is not
          > > > allowed to start new threads within EJB code. What about
          > > > within JSP's and JavaBeans?
          > > >
          > > > Thanks,
          > > >
          > > > Jason
          > > >
          > > >
          > >
          > >
          >
          >