public void exportExcelTemplate(List<DataItem> dataItems) throws Exception { Sheet sheet = workbook.createSheet("Sheet1"); Row headerRow = sheet.createRow(0); headerRow.createCell(0).setCellValue("Name"); headerRow.createCell(1).setCellValue("Age"); int rowNum = 1; for (DataItem data : dataItems) { Row row = sheet.createRow(rowNum++); row.createCell(0).setCellValue(data.getName()); row.createCell(1).setCellValue(data.getAge()); } FileOutputStream fileOut = new FileOutputStream("template.xlsx"); workbook.write(fileOut); fileOut.close(); workbook.close(); }