@Order(20.0)
      public class FileField extends AbstractFileChooserField {

        @Override
        protected String getConfiguredLabel() {
          return TEXTS.get("Filename");
        }

        @Override
        protected boolean getConfiguredTypeLoad() {
          return true;
        }
      }

byte[] content = IOUtility.getContent(new FileInputStream(getFileField().getValue()));

  File folder = new File(getDefaultFolder());
  FileChooser.setCurrentDirectory(getDefaultFolder());
  String filename = "Portrait*.*";
  FileChooser chooser = new FileChooser(folder, new String[]{"png", "jpg", "gif", "bmp", "*"}, true);
  chooser.setFileName(filename);
  File[] files = chooser.startChooser();