Can be anywhere from a few seconds to 4-5 minutes, depending on the size of the report.
-----Original Message----- From: Brett Connor [mailto:[EMAIL PROTECTED] Sent: Friday, July 23, 2004 10:40 AM To: Struts Users Mailing List Subject: Re: Intermediate loading page Ah. What is a typical length of time for a report generation? I'm inferring this is a serious resource constraint for your system. Rizwan Merchant wrote: >I want the variable to be reset if the browser is closed. The browser could >be closed while the report generation is in process (which is a separate >thread). There seems to be no way for the server to know that the browser >was closed. If I do not reset the session variable then I cannot start >generating another report until the first report thread dies on the server. > > >-----Original Message----- >From: Brett Connor [mailto:[EMAIL PROTECTED] >Sent: Friday, July 23, 2004 10:06 AM >To: Struts Users Mailing List >Subject: Re: Intermediate loading page > >Surely the session variable will be reset by the report generation process, >independent of any browser windows open, therefore no problem, you never >need to know if the browser has been closed or not. Or have I misunderstood? > >Brett > >Rizwan Merchant wrote: > > > >>Thanks for the previous input. I moved the report generation to a >>thread and set a session variable which is a boolean indicating that a >>report is currently being generated. Once the report generation is >>complete that session variable is set to false again. >>I have come across another problem though. Say a user starts generating >>a report. The boolean session variable is set to true. If the user >>tries to generate another report while the fist oneis not complete, >>then the boolean variable is checked and the user is not allowed to >>generate another report (until the first one is complete and the >>boolean session variable is set to false). >> >>In this scenario, if the user abruptly closes the intermediate page >>which is supposed to load the report , then the session variable is >>still set to true (indicating report is being generated) as the thread >>on the server has not finished running. If the user now tries to create >>another report then s/he will not be allowed to do so (until the thread >>on the server is done running). >> >>So I guess my question is : Is there any way to set a session variable >>when the user closes a browser window abruptly? >>Or is there another way to approach this problem? >> >>Thanks, >> >>-Riz. >> >>-----Original Message----- >>From: Craig McClanahan [mailto:[EMAIL PROTECTED] >>Sent: Friday, July 16, 2004 5:23 PM >>To: Struts Users Mailing List >>Subject: Re: Intermediate loading page >> >>Rizwan Merchant wrote: >> >> >> >> >> >>>Hi Craig, >>> >>>Thanks for the reply. I came across this solution, but does this not >>>mean that the user will only be able to generate one report at a time >>>(since we are storing the flag in the user's session)? If the user >>>starts generating a second report which is much smaller than the first >>>then would this not create a problem? >>> >>> >>> >>> >>> >>> >>> >>You could accomodate such a thing in several different ways, but how >>would the user even start requesting the second report? If they're >>sitting on the auto-repeat "Please Wait" page, they won't have the >>opportunity. If you want them to be able to go request a second report >>while the first one is still generating, you'll probably be better off >>just navigating back to the main menu (or something) after firing off >>the first thread, then let them fire off a different thread (using a >>different flag) for the second report >>-- then have a screen where they can "pick up" their completed reports >>and display them. >> >>If the computational effort to produce reports becomes severe, you >>might also consider using some sort of job queueing package so that a >>single background thread could do the report generation for all your >>users (one report at a time). If you go this way, the "pick up your >> >> >completed report" > > >>page becomes an even better idea. >> >> >> >> >> >>>Thanks again for your input. Much appreciated. >>> >>>-Riz. >>> >>> >>> >>> >>> >>> >>> >>Craig >> >> >> >> >> >>>-----Original Message----- >>>From: Craig McClanahan [mailto:[EMAIL PROTECTED] >>>Sent: Friday, July 16, 2004 3:37 PM >>>To: Struts Users Mailing List >>>Subject: Re: Intermediate loading page >>> >>>Rizwan Merchant wrote: >>> >>> >>> >>> >>> >>> >>> >>>>I am working on a web application using the Struts framework. Using a >>>>form on a jsp page, I generate a report which is displayed in pdf on >>>>a new screen. The report is generated through an Action class method. >>>>I would like to display a "Please wait" screen while the report is >>>>being generated. >>>> >>>>The action class method calls functions that generate a pdf file and >>>>then redirects control to that file. So I cannot use the flush() >>>>method to send html to the browser while the report is being >>>>generated (once a response is committed it cannot be written to >>>>again). Neither can I use the 'div' tag method as my new page is not >>>>a jsp page (it is a new browser window with pdf file displayed inside >>>> >>>> >it). > > >>>> >>>> >>>> >>>> >>>> >>>> >>>One common strategy for this sort of thing is to refactor your action >>>into several, along the following lines: >>> >>>* The Action that is currently creating the PDF should instead fire >>>off a background thread to do the report preparation. It will then >>>forward to a "Please Wait" page (see below). >>> >>>* The background thread should do whatever is needed to prepare the >>>PDF file, and set a flag variable in the user's session when it's >>>done, followed by terminating the thread. >>> >>>* The "Please Wait" page should say something like "Report generation >>>in progress", and use a meta-refresh tag to automatically submit >>>itself every few seconds, with the destination being a "Done Yet" >>>action. >>> >>>* The "Done Yet" action will consult the flag variable in the user's >>>session. >>>If its not there, forward back to the "Please Wait" page again. If >>>it's done, forward to the URL to retrieve the PDF itself. >>> >>>Craig >>> >>> >>> >>> >>> >>> >>> >>> >>>>My code is shown below.... >>>> >>>>//the jsp code calling the action >>>><nested:form action="/reports.do?action=getTransactionReports" >>>>target="_blank"> >>>> >>>> >>>>// The Action class >>>>public ActionForward getTransactionReports(ActionMapping mapping, >>>>ActionForm form, HttpServletRequest request, HttpServletResponse >>>>response) throws Exception { >>>> >>>>ICustomerAdministrationClient admin_impl = >>>>getCustomerAdministrationService(request); >>>> >>>>//enforce user permission >>>>enforceFeaturePermissions(EMSConstants.FEATURE_REPORTS, request, 1); >>>> >>>>EMSBaseAdminForm admin_form = (EMSBaseAdminForm)form; ReportsForm >>>>reportsForm = admin_form.getReportsForm(); >>>> >>>>//cant do this as it creates an IllegalStateException // PrintWriter >>>>html = response.getWriter(); // // >>>>html.print("<html>\n<head><title>my >>>>test</title></head>\n<body>"); // html.print("<p><img >>>>src=\"images/dpt_logo.jpg\"></body></html>"); >>>>// html.flush(); >>>>// html.close(); >>>> >>>> >>>>//if details type is summary then output format can only be PDF >>>>if(reportsForm.getDetailsType().equals(EMSConstants.REPORTS_SUMMARY)) >>>>reportsForm.setOutputFormat(EMSConstants.REPORTS_FORMAT_PDF); >>>> >>>>//generate the reports using jasper reports >>>>doJasperReports(reportsForm, request); >>>> >>>>CustomerForm customer_form = (CustomerForm)getSessionObject(request, >>>>"customerForm"); >>>>Collection all_region_list_forms = >>>>(Collection)getSessionObject(request, "allRegionListForms"); >>>> >>>>admin_form.setCustomerForm(customer_form); >>>>admin_form.setRegionListForms(all_region_list_forms); >>>>request.setAttribute(EMSConstants.FORM_VIEW, admin_form); >>>> >>>>String relativePath = File.separator + "temp_" + >>>>request.getSession().getId(); String pdfFilePath = File.separator + >>>>"temp" + relativePath + File.separator + "ReportinPDF.pdf"; String >>>>csvFilePath = File.separator + "temp" + relativePath + File.separator >>>>+ "ReportinCSV.dpt"; >>>> >>>>if(reportsForm.getOutputFormat().equals(EMSConstants.REPORTS_FORMAT_P >>>>D >>>>F)) return (new ActionForward(pdfFilePath, true)); >>>> >>>>return (new ActionForward(csvFilePath, true)); } >>>> >>>> >>>>Any help would be appreciated. Thanks. >>>>--------------------------------------------------------------------- >>>>- >>>>-- >>>> >>>><http://www.digitalpaytech.com/> >>>> >>>> >>>> >>>>Rizwan Merchant - Software Developer >>>>4105 Grandview Highway, Burnaby, BC, V5C 6B4, Canada >>>>Email: [EMAIL PROTECTED] >>>><mailto:[EMAIL PROTECTED]> >>>>Phone: 604-688-1959 x243 Fax: 604-687-4329 >>>>Toll Free: 1-888-687-6822 >>>>Website: www.digitalpaytech.com <outbind://11/www.digitalpaytech.com> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>--------------------------------------------------------------------- >>>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] > > > >--------------------------------------------------------------------- >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]
