java 读取 3124xlsx excel文件 CUsers25346Desktop3124xlsx 表格第一行为列名第一列是 CardID 和 第二列是 AttenDatatime 生成ListCardAttenDence cardAttenDenceList = new ArrayList; 其中CardID列的值是16进制的数字AttenDatatime列的值是yyyy-mm-dd

你可以使用Apache POI库来读取Excel文件。下面是一个例子，演示如何读取并解析Excel文件中的数据：

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class ExcelReader {

    public static void main(String[] args) {
        String filePath = "C:\\Users\\25346\\Desktop\\3124.xlsx";
        List<CardAttenDence> cardAttenDenceList = readExcel(filePath);
        // 在这里可以使用 cardAttenDenceList 进行后续操作
        for (CardAttenDence cardAttenDence : cardAttenDenceList) {
            System.out.println(cardAttenDence);
        }
    }

    public static List<CardAttenDence> readExcel(String filePath) {
        List<CardAttenDence> cardAttenDenceList = new ArrayList<>();

        try (FileInputStream fis = new FileInputStream(filePath);
             Workbook workbook = new XSSFWorkbook(fis)) {

            Sheet sheet = workbook.getSheetAt(0);
            Row firstRow = sheet.getRow(0);

            int cardIdColumnIndex = -1;
            int attenDatatimeColumnIndex = -1;

            // 找到 CardID 和 AttenDatatime 列的索引
            for (Cell cell : firstRow) {
                String cellValue = cell.getStringCellValue();
                if (cellValue.equalsIgnoreCase("CardID")) {
                    cardIdColumnIndex = cell.getColumnIndex();
                } else if (cellValue.equalsIgnoreCase("AttenDatatime")) {
                    attenDatatimeColumnIndex = cell.getColumnIndex();
                }
            }

            if (cardIdColumnIndex == -1 || attenDatatimeColumnIndex == -1) {
                throw new IllegalArgumentException("列名未找到");
            }

            // 从第二行开始读取数据
            for (int i = 1; i <= sheet.getLastRowNum(); i++) {
                Row row = sheet.getRow(i);

                String cardId = row.getCell(cardIdColumnIndex).getStringCellValue();
                String attenDatatime = row.getCell(attenDatatimeColumnIndex).getStringCellValue();

                cardAttenDenceList.add(new CardAttenDence(cardId, attenDatatime));
            }

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

        return cardAttenDenceList;
    }

    static class CardAttenDence {
        private String cardId;
        private String attenDatatime;

        public CardAttenDence(String cardId, String attenDatatime) {
            this.cardId = cardId;
            this.attenDatatime = attenDatatime;
        }

        public String getCardId() {
            return cardId;
        }

        public String getAttenDatatime() {
            return attenDatatime;
        }

        @Override
        public String toString() {
            return "CardAttenDence{" +
                    "cardId='" + cardId + '\'' +
                    ", attenDatatime='" + attenDatatime + '\'' +
                    '}';
        }
    }
}

注意，上述代码中使用的是XSSFWorkbook类，适用于读取.xlsx格式的Excel文件。如果要读取.xls格式的文件，你需要使用HSSFWorkbook类