question for filedownload jsp with commandLink and commandButton

[Yasushi Okubo]

Hi experts,

I have multiple download links [commandLink] /buttons[commandButton] on 
the same page.  I realized that a user needs to click twice to see an 
open directory window from the second attempt, I do not understand why 
this is happening.

The download page was implemented with jsp page. 
commandLink/commandbutton  are simply taking  a user to this download 
page by clicking a link or a button.

At the first click, a use always go to this page and the browser asks a 
user if one wants to save a directory or open on the browser. Then a 
user can decide to cancel or save or open. 
At the second attempts, the problem is that a user clicks link/button 
subsequently right after the first attempt, the action does not take a 
user to the jsp page, and it only reloads page with a round trip.
Then a user needs to click a link/ a button  second time, then it works.

Could someone advise me why this is happening and is there anyway to 
stop this ?

I implemented a commandbutton + actionListener [in backing bean] 
solution for file download, but the result was the same.  From the 
second attempt, a user always needs to click twice [double click] button.
I saw the one post on google is that adding _blank on form tag helps, 
but it actually did not help at all.

Any idea ?

yasushi


==== partial code for jsp page ====
....

if(allowCache == null || allowCache.equalsIgnoreCase("false"))
   {
       response.setHeader("pragma", "no-cache");
       response.setHeader("Cache-control", "no-cache, no-store, 
must-revalidate");
       response.setHeader("Expires", "01 Apr 1995 01:10:10 GMT");
       response.addHeader("Cache-Control", "post-check=0, pre-check=0");
       response.setDateHeader ("Expires", 0);
   }

   if(contentType!=null)
   {
       response.setContentType(contentType);
   }

   if(fileName != null)
   {

       StringBuffer contentDisposition = new StringBuffer();

       if("true".equals(openDirectly))
       {
           contentDisposition.append("attachment;");
            logger.info("==> attachement");
       }

       contentDisposition.append("filename=\"");
       contentDisposition.append(fileName);
       contentDisposition.append("\"");

       response.setHeader ("Content-Disposition", 
contentDisposition.toString());
   }

   if (bytes != null)
   {
       response.getOutputStream().write(bytes);
   }