code: private Workbook exportExcelNoTemplateHandler(List<NoTemplateSheetWrapper> sheetWrappers, boolean isXSSF)
              throws Excel4JException {
  
          Workbook workbook;
          if (isXSSF) {
              workbook = new XSSFWorkbook();
          } else {
              workbook = new HSSFWorkbook();
          }
  
          // 导出sheet
          for (NoTemplateSheetWrapper sheet : sheetWrappers) {
              generateSheet(workbook, sheet.getData(),
                      sheet.getClazz(), sheet.isWriteHeader(),
                      sheet.getSheetName()
              );
          }
  
          return workbook;
      }
docs: 多sheet数据导出