java - 如何使用java在Excel中按列读取？

Question

如果假设Excel在任何列中具有日期值格式，我需要将整个列更改为日期格式，并在日期列的空记录中插入“N/A”值。任何人，请帮我解决这个问题。

Answer 1

private void processExcelFromLocal() {

        FileInputStream fis = null;
        try {
            fis = new FileInputStream(
                    new File("/home/rajat/Downloads/excelFile.xlsx"));
        } catch (FileNotFoundException e) {
            e.printStackTrace();

        }

        if (fis != null) {

            @SuppressWarnings("resource")
            XSSFWorkbook workbook = null;
            try {
                workbook = new XSSFWorkbook(fis);
            } catch (IOException e) {
                e.printStackTrace();

            }

            XSSFSheet spreadsheet = workbook.getSheetAt(0);

            for (int i = 0; i <= spreadsheet.getLastRowNum(); i++) {
                XSSFRow row = spreadsheet.getRow(i);
                String value = row.getCell().getStringCellValue();    
            }
        }

        try {
            fis.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }