/**
 * @Author: JCccc
 * @Date: 2022-8-31 02:49
 * @Description:
 */
public class ExcelUtil {
    protected static final Logger logger = LoggerFactory.getLogger(ExcelUtil.class);
    private static final String XLS = "xls";
    private static final String XLSX = "xlsx";
    private static final String SPLIT = ".";
    public static Workbook getWorkbook(MultipartFile file) {
        Workbook workbook=null;
        try {
            // 获取Excel后缀名
            String fileName = file.getOriginalFilename();
            if (StringUtils.isEmpty(fileName) || fileName.lastIndexOf(SPLIT) < 0) {
                logger.warn("解析Excel失败，因为获取到的Excel文件名非法！");
                return null;
            }
            String fileType = fileName.substring(fileName.lastIndexOf(SPLIT) + 1, fileName.length());
            // 获取Excel工作簿
            if (fileType.equalsIgnoreCase(XLS)) {
                workbook = new HSSFWorkbook(file.getInputStream());
            } else if (fileType.equalsIgnoreCase(XLSX)) {
                workbook = new XSSFWorkbook(file.getInputStream());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return workbook;
    }
    public static List<String> getSheetTitles( Workbook workbook) {
        //拿第一个sheet表
        Sheet sheet = workbook.getSheetAt(0);
        // 校验sheet是否合法
        if (Objects.isNull(sheet)) {
            return null;
        }
        // 获取第一行数据（假如第一行就是列名）
        Row sheetTitleRow = sheet.getRow(sheet.getFirstRowNum());
        // 取出最后一列
        short lastCellNum = sheetTitleRow.getLastCellNum();
        List<String> sheetTitleList = new LinkedList<>();
        for (int i = 0; i < lastCellNum; i++) {
            //取出每一列的名
            String cellValue = sheetTitleRow.getCell(i).getStringCellValue();
            sheetTitleList.add(cellValue);
        }
        return sheetTitleList;
    }
}