Unwanted File Download box in JSF - Problem while Saving State.

Question

Hi,
I am having a situation wherin there are multiple command links dynamically generated in a dataTable.When I click on any one of the links a file download dialogue pops up to save/open a pdf doc.Irrespective of any operations on the download dialogue, if I click on anyother link (i.e this is the 2nd click on tat page)
then the file download doesnt pop up and instead the page is refreshed.
On the 3rd click , the file download again pops up.
The code in the action method of the command link goes like this
public void showPDF() {
byte[] pdf = // gets the data from another place.
FacesContext faces = FacesContext.getCurrentInstance();
          HttpServletResponse response = (HttpServletResponse) faces.getExternalContext().getResponse();
          response.setContentType("application/pdf");
          response.setContentLength(pdf.length);
          response.setHeader("Content-disposition", "attachment");
          response.setHeader("Cache-Control", "cache, must-revalidate");
          response.setHeader("Pragma", "public");
          try {
               ServletOutputStream output = response.getOutputStream();
               output.write(pdf);
          } catch (IOException e) {
                    log.debug("IOException in viewPdf: " + e.toString());
     faces.responseComplete();
}To fix the above problem ...I have included the following 2 lines of code just before invoking the responseComplete() method :
  StateManager stateManager = (StateManager)    
                                                                faces.getApplication().getStateManager();
     stateManager.saveSerializedView(faces);This solves the above problem but causes another problem for which I need help :
There is a value change listener in my jsp.When I change the value in a drop down list in the same page, the file download dialogue is poping up. which shuld only pop up when am clicking any one of the command links.
I debugged thru the code and found out that after the value change listener action method is finished executing it jumps and executes the above showPDF() method.
Seems its something to do with saving of the client state.
It will be of great help anyone can advise on this.
Thanks
Archan

Answer 1

Hi,
I am having a situation wherin there are multiple command links dynamically generated in a dataTable.When I click on any one of the links a file download dialogue pops up to save/open a pdf doc.Irrespective of any operations on the download dialogue, if I click on anyother link (i.e this is the 2nd click on tat page)
then the file download doesnt pop up and instead the page is refreshed.
On the 3rd click , the file download again pops up.
The code in the action method of the command link goes like this
public void showPDF() {
byte[] pdf = // gets the data from another place.
FacesContext faces = FacesContext.getCurrentInstance();
          HttpServletResponse response = (HttpServletResponse) faces.getExternalContext().getResponse();
          response.setContentType("application/pdf");
          response.setContentLength(pdf.length);
          response.setHeader("Content-disposition", "attachment");
          response.setHeader("Cache-Control", "cache, must-revalidate");
          response.setHeader("Pragma", "public");
          try {
               ServletOutputStream output = response.getOutputStream();
               output.write(pdf);
          } catch (IOException e) {
                    log.debug("IOException in viewPdf: " + e.toString());
     faces.responseComplete();
}To fix the above problem ...I have included the following 2 lines of code just before invoking the responseComplete() method :
  StateManager stateManager = (StateManager)    
                                                                faces.getApplication().getStateManager();
     stateManager.saveSerializedView(faces);This solves the above problem but causes another problem for which I need help :
There is a value change listener in my jsp.When I change the value in a drop down list in the same page, the file download dialogue is poping up. which shuld only pop up when am clicking any one of the command links.
I debugged thru the code and found out that after the value change listener action method is finished executing it jumps and executes the above showPDF() method.
Seems its something to do with saving of the client state.
It will be of great help anyone can advise on this.
Thanks
Archan