how to refresh ProgressBar in any event of the Upload progress

I am uloading using com.vaadin.ui.Upload; a file that after is upload in the

@Override
public void uploadFinished(Upload.FinishedEvent finishedEvent

I process the content as CSV file and post the data into a REST Service, this part of the process is takes much more time than the upload itself, in the upoad process of the file the progresbar is update but I am not able to update and show progress from any other event, I use the same code :

@Override

        public void updateProgress(final long readBytes, final long contentLength) {

            // this method gets called several times during the update

            progressBar.setValue(readBytes / (float) contentLength);

            textualProgress.setValue("Processed " + readBytes + " bytes of " + contentLength);

          

that I use in the updateProgress in the uploadFinished, but not changes are show in info window. 

@Override

        public void uploadFinished(Upload.FinishedEvent finishedEvent) {

              state.setValue("Idle");

              textualProgress.setValue("Processe FINISH " + 888888 + " bytes of " + 222222);
/// this change is not refresh into the info's window

          try {

            /* Let's build a container from the CSV File */
            FileReader reader = new FileReader(tempFile);
            List<FSData> listFSData = buildContainerFromCSV(reader);
            int i = 0;
            reader.close();

            tempFile.delete();

            uploadInfoWindow.setClosable(true);

            postToREST(listFSData);

 How can I get a progress indicator that is show the progress when postToREST(listFSData) is running?