Strange error when downloading blob

Question

ADF 11g
Hello
I have a pdf file uploaded to the DB as a blob column.
I am now trying to download it.
I've tried to convert the Kuba [http://kuba.zilp.pl/?id=1] example from ADF 10 to 11.
I have page showing an af:table.
Clicking on the filename column runs the following :
    public BindingContainer getBindings() {
        FacesContext fc = FacesContext.getCurrentInstance();       
        return (BindingContainer)fc.getApplication().evaluateExpressionGet(fc,"#{bindings}", BindingContainer.class);
    public String onDownLoad() {
         BindingContainer bindings = getBindings();
         DCIteratorBinding itr = (DCIteratorBinding) bindings.get ("SttAttachedFilesView1Iterator");
         Row r = itr.getCurrentRow();
         BlobDomain file = (BlobDomain)r.getAttribute("FileContent");
         String fileName = (String)r.getAttribute("FileName");
         FileOperations.downloadFile( fileName,  file);
         return null;
     }The actual download code is
public class FileOperations {
    public FileOperations() {
    public static String getMimeType(String fileName){
        String mime = null;
        String ext = fileName.toLowerCase();
             if(ext.endsWith(".pdf")) { mime = "application/pdf"; }
        else if(ext.endsWith(".doc")) { mime = "application/msword"; }
        else if(ext.endsWith(".ppt")) { mime = "application/vnd.ms-powerpoint"; }
        else if(ext.endsWith(".rar")) { mime = "application/octet-stream"; }
        else if(ext.endsWith(".zip")) { mime = "application/zip"; }
     return mime;
    public static synchronized void downloadFile( String fileName, BlobDomain blobDomain )
        FacesContext facesContext = FacesContext.getCurrentInstance();
        ExternalContext extContext = facesContext.getExternalContext();
        Long length = blobDomain.getLength();      
        String fileType = getMimeType(fileName);
        HttpServletResponse response = (HttpServletResponse) extContext.getResponse();
        response.setHeader("Content-Disposition", "attachment;filename=\"" + fileName + "\"");
        response.setContentLength((int) length.intValue());
        response.setContentType( fileType );
        try {
            InputStream in = blobDomain.getBinaryStream();
            OutputStream out = response.getOutputStream();
            byte[] buf = new byte[1024];
            int count;
            while ((count = in.read(buf)) >= 0) {
                out.write(buf, 0, count);
            in.close();
            out.flush();
            out.close();
            facesContext.responseComplete();
        } catch (IOException ex) {
            System.out.println(ex.getMessage());
            ex.printStackTrace();
}Whats happening is the first time I click on the filename the file is downloaded from the DB correctly.
If I click a second time I get the following errors :
<25 juil. 2009 12.54. h CEST> <Error> <HTTP> <BEA-101083> <Connection failure.
java.net.ProtocolException: Didn't meet stated Content-Length, wrote: '0' bytes instead of stated: '156751' bytes.
     at weblogic.servlet.internal.ServletOutputStreamImpl.ensureContentLength(ServletOutputStreamImpl.java:425)
     at weblogic.servlet.internal.ServletResponseImpl.ensureContentLength(ServletResponseImpl.java:1451)
     at weblogic.servlet.internal.ServletResponseImpl.send(ServletResponseImpl.java:1494)
     at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1437)
     at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
     Truncated. see log file for complete stacktrace
>
<25 juil. 2009 12.54. h CEST> <Error> <HTTP> <BEA-101104> <Servlet execution in servlet context "ServletContext@18785780[app:UpLoadDownload module:UpLoadDownload-ViewController-context-root path:/UpLoadDownload-ViewController-context-root spec-version:2.5]" failed, java.net.ProtocolException: Didn't meet stated Content-Length, wrote: '0' bytes instead of stated: '156751' bytes..
java.net.ProtocolException: Didn't meet stated Content-Length, wrote: '0' bytes instead of stated: '156751' bytes.
     at weblogic.servlet.internal.ServletOutputStreamImpl.ensureContentLength(ServletOutputStreamImpl.java:425)
     at weblogic.servlet.internal.ServletResponseImpl.ensureContentLength(ServletResponseImpl.java:1451)
     at weblogic.servlet.internal.ServletResponseImpl.send(ServletResponseImpl.java:1494)
     at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1437)
     at weblogic.work.ExecuteThread.execute(ExecuteThread.java:201)
     Truncated. see log file for complete stacktrace
>It as if the inputStream is empty the second time round even though the lenght is correct.
If I close the application and restart I can download the file again.
I've added an execute button to re-execute the query after the first download but the problem persists.
Anybody got any ideas ?
Regards
Paul

Answer 1

If I add
OperationBinding operation = getBindings().getOperationBinding("Rollback");        
operation.execute();         to the end of the onDownLoad method the error dissapears and everything works as expected.
If I replace Rollback with either Commit or Execute the problem continues.
Whats going on here its as if the blob field isn't really there....
Regards
Paul
Bump - because I've been on holiday :-)
Edited by: Paul (MITsa) on 10-Aug-2009 04:20