code: private void getImportResource() throws CmsVfsException {
  
          // get the import resource
          m_importResource = new File(m_importFolderName);
          // check if this is a folder or a ZIP file
          if (m_importResource.isFile()) {
              try {
                  m_zipStreamIn = new ZipInputStream(new FileInputStream(m_importResource));
              } catch (IOException e) {
                  // if file but no ZIP file throw an exception
                  throw new CmsVfsException(
                      Messages.get().container(Messages.ERR_NO_ZIPFILE_1, m_importResource.getName()),
                      e);
              }
          }
      }
docs: Stores the import resource in an Object member variable.<p>
  @throws CmsVfsException if the file to import is no valid zipfile