I'm sorry Michael but I no longer have a working example. It's not hard to create though - here's a quick and dirty effort based on the case Harald described below, you might have to tweak and debug a little to get it working smoothly, because I have forgotten the exact JS syntax and I haven't got time to test it. Hope this helps :)
1. Write a servlet called "DataUpdateCheck" that checks the database thread for new data, and depending on whether there is new data or not, returns to the browser EITHER this: <html> <head> <script language="JavaScript"> <!-- delay=3500; // this could be substituted using a config value from web.xml updateUri = "/mywebApp/DataUpdateCheck"; // change this to suit your webapp x=setTimeout('document.location = "' + updateUri + '";', delay); //--> </script> </head> </html> OR this: <html> <head> <script language="JavaScript"> <!-- updateUri = "/mywebApp/MainDataPage"; // change this to suit your webapp document.parent.mainDataFrame.location=updateUri; //--> </script> </head> </html> 2. Write a servlet called "MainDataPage" which produces the data display for the user. You will probably have written this page already. 3. Then write a HTML page that combines the two servlets above: <HTML> <HEAD> <TITLE></TITLE> </HEAD> <frameset rows="0,*"> <frame name="dataUpdateCheckFrame" src = "DataUpdateCheck"> <frame name="mainDataFrame" src = "MainDataPage"> </frameset> </HTML> You could probably use <IFRAME>s instead of <FRAME>s to make things look neater in the browser. > -----Original Message----- > From: Michael McGrady [mailto:[EMAIL PROTECTED] > Sent: Tuesday 19 October 2004 14:57 > To: Tomcat Users List > Subject: [OT] Re: Push-Server with Tomcat > > > Do you have a simple sample of this Steve? If so, I would > sure like to > see it. > > Michael McGrady > > Steve Kirk wrote: > > >Not sure if this is stating the obvious, or this is the > approach you've > >already taken, but it's not necesary to refresh the whole > page that is > >displaying your data every few seconds. You can have an > invisible frame > >that runs the JS timer that you describe. That frame could have > >src="/mywebapp/DataUpdateCheck" which is a servlet that > returns just a > >simple js function - if there is new data, the function > reloads it into the > >visible frame, otherwise it reloads itself after a couple of > seconds to > >check for more data. > > > > > > > >>-----Original Message----- > >>From: Steve Kirk [mailto:[EMAIL PROTECTED] > >>Sent: Tuesday 19 October 2004 12:41 > >>To: 'Tomcat Users List'; [EMAIL PROTECTED] > >>Subject: RE: Push-Server with Tomcat > >> > >> > >> > >>Seems to me that browsers are inherently "pull" technology > >>because at the > >>basic level they send a single request and await a single > >>response to it. > >>You can't push stuff at them that they haven't requested. > >>Hence why you > >>have to use an approach like your javascript - which, by the > >>way, I have > >>used in the past in a web-based control system without > >>problems - it might > >>not feel that elegant, but it does work. > >> > >>I would think that to get a true push approach you would have > >>to extend the > >>browser capabilities using a plugin of some sort, e.g. java > >>applet / activex > >>/ etc. Never tried this myself though so can't comment if > >>this will solve > >>it. > >> > >> > >> > >>>-----Original Message----- > >>>From: Harald Henkel [mailto:[EMAIL PROTECTED] > >>>Sent: Tuesday 19 October 2004 09:51 > >>>To: Tomcat Users List > >>>Subject: Push-Server with Tomcat > >>> > >>> > >>>Hello everybody. > >>> > >>>Is it possible (with Tomcat) to write an application that, > >>>once startet > >>>will send a new HTML page to a client, genereated using > changed data > >>>from a database ? > >>> > >>>What I want to do is using oracle alerts to alert a waiting Tomcat > >>>thread of changed data, let it collect the data and generate > >>>one or more > >>>HTML pages sent to different clients, i.e. a specific frame in the > >>>browser on the client. > >>> > >>>Or would I have to have a Java app runing in that frame ? > >>> > >>>At the moment I'm doing this using a JavaScript timer on the client > >>>requesting a new page for that frame every couple of seconds, > >>>but for this application push would really be better. > >>> > >>>With kind regards, > >>>Harald Henkel > >>> > >>>-- > >>>Harald Henkel > >>> > >>>GS automation GmbH > >>>Winterstraße 2 > >>>82223 Eichenau > >>>Germany > >>>Tel: + 49-8141-35 731-37 > >>>Fax: + 49-8141-35 731-38 > >>>Mobile: + 49-178-7829126 > >>>e-mail: [EMAIL PROTECTED] > >>>Web: www.GS-automation.DE > >>> > >>> > >>> > >>> > >>------------------------------------------------------------ > --------- > >> > >> > >>>To unsubscribe, e-mail: [EMAIL PROTECTED] > >>>For additional commands, e-mail: > [EMAIL PROTECTED] > >>> > >>> > >>> > >>> > >> > >>------------------------------------------------------------ > --------- > >>To unsubscribe, e-mail: [EMAIL PROTECTED] > >>For additional commands, e-mail: [EMAIL PROTECTED] > >> > >> > >> > >> > > > > > > > >--------------------------------------------------------------------- > >To unsubscribe, e-mail: [EMAIL PROTECTED] > >For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]