code: public static void writeWorkBookToExcel(Workbook workbook, OutputStream os) throws WriteExcelException {
          try {
              workbook.write(os);
          } catch (IOException e) {
              throw new WriteExcelException(e.getMessage());
          }
      }
docs: 将指定WorkBook写入指定文件中
  
  @param workbook 指定工作簿
  @param os       指定输出流,需要手动关闭
  @throws WriteExcelException 出现I/O异常抛出