设置输出文件的列宽，防止文件过于丑陋

Sheet sheet = workbook.createSheet(FileConstants.ERROR_FILE_SHEET_NAME);
sheet.setColumnWidth(0, 40 * 256);
sheet.setColumnWidth(1, 20 * 256);
sheet.setColumnWidth(2, 20 * 256);
sheet.setColumnWidth(3, 20 * 256);

实现标题行的第一个字符为红色，效果如图

//这边的0,1   就是设置第一个字符  

Font font = workbook.createFont(); font.setColor(IndexedColors.RED.getIndex());

RichTextString store = workbook.getCreationHelper().createRichTextString(FileConstants.UPDATE_TEMPLATE_NAMES.get(Constants.ZERO)); store.applyFont(0, 1, font);

titleRow.createCell(Constants.ONE_INT).setCellValue(store);

判断如果是第一列的话   设置字体为红色

if (Constants.ZERO.equals(columnIndex)) {cellStyle.setFont(font);cell.setCellStyle(cellStyle);
}

将文件上传oss保存，可以忽略

try (InputStream inputStream = new ByteArrayInputStream(out.toByteArray())) {aliyunOssUtil.uploadFile(ossFilePath, inputStream);
}

 完整代码如下：

    private void uploadErrorFile(List<BatchUpdateStatusFileDTO> list, String fileBatchId) {try (ByteArrayOutputStream out = new ByteArrayOutputStream();Workbook workbook = new XSSFWorkbook()) {Sheet sheet = workbook.createSheet(FileConstants.ERROR_FILE_SHEET_NAME);sheet.setColumnWidth(0, 40 * 256);sheet.setColumnWidth(1, 20 * 256);sheet.setColumnWidth(2, 20 * 256);sheet.setColumnWidth(3, 20 * 256);// 创建标题行Row titleRow = sheet.createRow(0);titleRow.createCell(Constants.ZERO).setCellValue(StringPool.EMPTY);Font font = workbook.createFont();font.setColor(IndexedColors.RED.getIndex());RichTextString store = workbook.getCreationHelper().createRichTextString(FileConstants.UPDATE_TEMPLATE_NAMES.get(Constants.ZERO));store.applyFont(0, 1, font);titleRow.createCell(Constants.ONE_INT).setCellValue(store);RichTextString number = workbook.getCreationHelper().createRichTextString(FileConstants.UPDATE_TEMPLATE_NAMES.get(Constants.ONE_INT));number.applyFont(0, 1, font);titleRow.createCell(Constants.TWO_INT).setCellValue(number);RichTextString status = workbook.getCreationHelper().createRichTextString(FileConstants.UPDATE_TEMPLATE_NAMES.get(Constants.TWO_INT));status.applyFont(0, 1, font);titleRow.createCell(Constants.THREE_INT).setCellValue(status);// 创建数据行for (int i = 0; i < theResList.size(); i++) {BatchUpdateStatusFileDTO data = theResList.get(i);Row row = sheet.createRow(i + 1);createCell(row, Constants.ZERO, data.getCheckResult(), workbook, font);createCell(row, Constants.ONE_INT, data.getSalesStore(), workbook, font);createCell(row, Constants.TWO_INT, data.getSalesOrder(), workbook, font);createCell(row, Constants.THREE_INT, data.getSalesStatus(), workbook, font);}String ossFilePath = String.format(FileConstants.BATCH_UPDATE_ERROR_FILE_PATH, fileBatchId);// 将Excel输出为InputStreamworkbook.write(out);try (InputStream inputStream = new ByteArrayInputStream(out.toByteArray())) {aliyunOssUtil.uploadFile(ossFilePath, inputStream);}} catch (Exception e) {log.error("---Modify the order status in batches, failed to upload an error file---", e);}}private void createCell(Row row, int columnIndex, Object value, Workbook workbook, Font font) {Cell cell = row.createCell(columnIndex);if (value instanceof String) {cell.setCellValue((String) value);} else if (value instanceof Integer) {cell.setCellValue((Integer) value);} else {cell.setCellValue(value.toString());}CellStyle cellStyle = workbook.createCellStyle();cellStyle.setWrapText(Boolean.TRUE);cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);cell.setCellStyle(cellStyle);if (Constants.ZERO.equals(columnIndex)) {cellStyle.setFont(font);cell.setCellStyle(cellStyle);}}