code: public static XlsxWorkbook getWorkbook(File file) throws IOException
      {
          try
          {
              return new XlsxWorkbook(file);
          }
          catch(Docx4JException e)
          {
              if(e.getCause() != null
                  && e.getCause() instanceof IOException)
                  throw (IOException)e.getCause();
              else
                  throw new IOException(e);
          }
      }
docs: Returns an existing workbook object.
  @param file The file with the workbook
  @return The existing workbook object
  @throws IOException if the workbook cannot be opened