code: public static Workbook createBook(File excelFile, String password) {
  		try {
  			return WorkbookFactory.create(excelFile, password);
  		} catch (Exception e) {
  			throw new POIException(e);
  		}
  	}
docs: 创建或加载工作簿，只读模式
  
  @param excelFile Excel文件
  @param password Excel工作簿密码，如果无密码传{@code null}
  @return {@link Workbook}