ADF and BLOBs

Question

Hi All,
What is the best way to display a PDF document stored in a blob column using ADF, BC4J and Struts?
Thanks,
Matt

Answer 1

Hi Matt,
here is my solution I use in an Jdev904 appliation with Tomcat as Webcontainer. I have delete some code to show just the important parts. The solution works for me, but everyone is invited to post some improvements.
Markus
1.) EntityObject with attribute of type BlobDomain (and a default VO based on EO).
2.) a JSP containing a line like
download
3.) showPDFDocument.do Action:
public class ShowPDFDocument extends Action {
public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
BlobDomain blob = (BlobDomain) row.getAttribute("Blob");
byte[] blobArray = blob.toByteArray();
String docURI = (String)rows[0].getAttribute("Name");
if (docURI.endsWith(".pdf") == false){
docURI += ".pdf";
docURI = "pdfs/" + docURI;
request.getSession().setAttribute("PDFfilename", docURI);
request.getSession().setAttribute("thePDF", blobArray);
return new ActionForward(docURI, true);
4.) The redirect calls the PDFResponseServlet:
public class PDFResponseServlet extends HttpServlet {
protected void doPost(HttpServletRequest p0, HttpServletResponse p1)
throws ServletException, IOException {
byte[] blobArray = (byte[]) request.getAttribute("thePDF");
if (blobArray == null){
blobArray = (byte[]) request.getSession().getAttribute("thePDF");
Boolean isDownload = (Boolean) request.getSession().getAttribute("doPDFDownload");
if (isDownload != null && isDownload.booleanValue() == true){
String filename = (String) request.getSession().getAttribute("PDFfilename");
if (filename == null || filename.length()==0){
filename = "myPDF.pdf";
response.setHeader("Content-Disposition", "attachment; filename=" + filename);
response.setContentType("application/pdf;charset=windows-1252");
response.setContentLength(blobArray.length);
response.getOutputStream().write(blobArray);
response.getOutputStream().flush();
5.) web.xml
<servlet>
<servlet-name>PDFResponse</servlet-name>
<servlet-class>com.trivadis.efa.controller.PDFResponseServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>PDFResponse</servlet-name>
<url-pattern>/pdfs/*</url-pattern>
</servlet-mapping>