// Open the rptDocument
  reportDocument = getReportEngine().openReportDocument(rptDocumentPath);

  // Create the render task, configured for the wanted export format
  IRenderTask renderTask = getReportEngine().createRenderTask(reportDocument);

  IRenderOption options = new RenderOption();
  options.setOutputFormat("pdf");
  options.setOutputFileName("myfile.pdf");
  renderTask.setRenderOption(options);

                
  try {
    // Launch the render task and close it 
    renderTask.render();
    renderTask.close();
                                        
    // Close the rptDocument
    reportDocument.close();
                    
    // Finally, open the target file with the right application
    Program.launch(exportFileName);
                    
  } catch (final EngineException e) {
    Syso ....
  }