primefaces extension document viewer showing empty

Question

primefaces 5.3 pe 4.0

i am using the document viewer to display a pdf using streamed content but it is showing me and empty file.

opening the page and getting the streamed content

<h:commandLink actionListener="#{meetBean.previewbuttonAction}"  action="meetingpreview.xhtml" target="_blank">
                         <f:attribute name="attachment" value="#{meetattachment}"></f:attribute>
                         preview</h:commandLink>

making streamed content from file

public void previewbuttonAction(ActionEvent actionEvent) throws IOException {
         Meetingsattachment ma=(Meetingsattachment) actionEvent.getComponent().getAttributes().get("attachment");

            try{

            InputStream stream = new FileInputStream(new File(ma.getAttachment()));
            setStreamed(new DefaultStreamedContent(stream));

            }
            catch(NullPointerException ne){
                 FacesContext context = FacesContext.getCurrentInstance();

                    context.addMessage(null, new FacesMessage("File Unavailable") );
            }

        }

document viewer

<pe:documentViewer value="#{meetBean.streamed}" height="500"></pe:documentViewer>

but all it is showing me is an empty document

the file location is correct /path/to/files/t1-1323583810/1.pdf, i am doing everything exactly like in the showcase so i am not sure how to debug this and move forward