Java EE (Java Enterprise Edition) General Discussion

 public void download() {
        HttpServletResponse res = HttpJSFUtil.getResponse();
        res.setContentType("application/pdf");
        String filename = "my_document_";
        filename += CalendarUtil.formatDateValueMerged(new Date());
        filename += ".pdf";
        res.setHeader("Content-disposition", "attachment; filename=" + filename);
        try {
            ServletOutputStream out = res.getOutputStream();           
            if(subCategoryId != null){
            articleDTO = action.getArticleById(subCategoryId);
            out.write(getBytes(articleDTO.getContent()));//articleDTO.getContent() is String
            }


        } catch (IOException ex1) {
            ex1.printStackTrace();
        }
        FacesContext faces = FacesContext.getCurrentInstance();
        faces.responseComplete();
    }

    public static byte[] getBytes(Object obj) throws java.io.IOException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        ObjectOutputStream oos = new ObjectOutputStream(bos);
        oos.writeObject(obj);
        oos.flush();
        oos.close();
        bos.close();
        byte[] data = bos.toByteArray();
        return data;
    }

 <h:commandLink id="download" action="#{CategoriesBean.download}" value="Download">
                    <f:param name="subCategoryId" value="#{CategoriesBean.subCategoryId}"/> 
                </h:commandLink>