Need help to download csv file in application by writting to outputstream.

Question

HI All,
Requirment of my client is donloading CSV file from portal.
My approach  is:
On clicking "Download" button in JSP I am calling an action in controller and from here I am redirecting call to DownloadCSV.jsp where i am writing to output stream of response.
Action called in controller:
     @Jpf.Action(forwards = { @Jpf.Forward(name = StaticConstants.SUCCESS, redirect = true, path = "DownloadCSV.jsp") })
     public Forward gotoReports() {
          Forward forward = new Forward(StaticConstants.SUCCESS);
          return forward;
Download jsp:
response.resetBuffer();
     response.reset();
     response.setContentType("application/vnd.ms-excel");
     response.addHeader("Content-Disposition", "attachment;filename="+ companyId +"_Audit_Report.csv");
     ServletOutputStream os = response.getOutputStream();
          os .println();
          os .print("DATE");
          os .print("USER");
os .println();
os.flush();
os.close();
I am able to download the csv file in excel. But after that i am not able to perform any operation in portal page. Mouser pointer becomes busy and cant click on anything.
Second approach followed:
I wrote the code for writting to outputstream of outputresponse in controller action itself and forwarded to the same jsp where my download button resides.
Problem:
Download happens perfectly but the excel in csv format contains the portal framework generated content also other than content i wrote to response.
If u have any other approach to download an excel without redirecting to JSP plz let me know. Coing is being done in 10.2 weblogic portal.
Please help. Its very urgent.
Plz let me know how a file can be downloded in portal context without keeping a file at server side. I need to download file by writting to outputstream.
If it is possible plz attach one small example project also.
Thanks a ton in advance.
It is very important plz do reply.

Answer 1

Hi Srinivas,
For downloading binary content that is not text/html, the Oracle WebLogic Portal content management tools use javascript in an onclick event handler to set the window URL to the URL of a download pageflow controller: window.location = url. The content management tools are in a portal so it should be possible for you to do the same thing.
The url is a custom pageflow controller that streams the bytes to the response. It sounds like you already have a pageflow you could recycle to use in that way. You don't want to stay within your portlet pageflow because then you will be streaming bytes into the middle of a portal response. You want a separate download pageflow that you invoke directly, outside of the portal framework (in other words, don't invoke it by rendering a portlet that invokes the pageflow).
You can set the url to invoke the pageflow directly by giving the path to the pageflow controller from the web root (remember the pageflow path matches the package name of the pageflow controller class) like this: "/content/node/nodeSelected/download/DownloadContentController.jpf"
By the way, for the case of text/html, the tools uses a standalone portlet URL so that the text/html is not rendered in the browser window, which would replace the portal markup (because the browser renders text/html by default, instead of giving you a download widget or opening some other application to deal with the bytes).