PDF files

Hi,
I'm a beginner java developer, and I'm developing a desktop
application, it contains form generate reports for user in pdf format
and save it in temporary file.
when user view the archived report, he could save it in another path
(for example: myDocuments)... but the new saved file is empty except
from a logo
this is the code to save the pdf ... can anybody help my to find the
problem? thanx in advance

public void export(){
  Properties m_ctx=Env.getCtx();
  JFileChooser chooser = new JFileChooser();
  chooser.setDialogType(JFileChooser.SAVE_DIALOG);
        chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
        chooser.setDialogTitle(Msg.getMsg(Env.getCtx(), "Export"));
        chooser.addChoosableFileFilter(new
ExtensionFileFilter("pdf" ,Msg.getMsg(m_ctx, "FilePDF")));

        if(chooser.showSaveDialog(this)!= JFileChooser.APPROVE_OPTION)
         return;

        File file =
ExtensionFileFilter.getFile(chooser.getSelectedFile(),
chooser.getFileFilter());
        Viewer viewer = new Viewer();
        try{
         PDFGenerator.getPDFAsStream(new
FileOutputStream(file),layoutEngine.getPageable(false));
         file.createNewFile();

        }catch(Exception e){
         e.printStackTrace();
        }