post方法下載excel

main{
　　

ByteArrayOutputStream outputStream = excelUtil.exportExcel(header, data);
// 返回檔案流給前端
String fileName = "fixedSavingExport" + CommUtil.getComputerDate() + ".csv";

return ResponseEntity.ok()
        .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename="+fileName+"")
        .contentType(MediaType.parseMediaType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"))
        .body(new ByteArrayResource(outputStream.toByteArray()));

}

public ByteArrayOutputStream exportExcel(List<String> header, List<List<String>> data) {
    try (Workbook workbook = new XSSFWorkbook();
         ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {
        Sheet sheet = workbook.createSheet("Sheet1");

        // 建立表頭
        Row headerRow = sheet.createRow(0);
        for (int i = 0; i < header.size(); i++) {
            headerRow.createCell(i).setCellValue(header.get(i));
        }

        // 填充資料
        for (int i = 0; i < data.size(); i++) {
            Row dataRow = sheet.createRow(i + 1);
            List<String> rowData = data.get(i);
            for (int j = 0; j < rowData.size(); j++) {
                dataRow.createCell(j).setCellValue(rowData.get(j));
            }
        }

        try {
            workbook.write(outputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }

        return outputStream;
    } catch (IOException e) {
        e.printStackTrace();
    }

    return null;
}