将excel导入到list<list<Obj>>中

package io.renren.utils;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
 
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.web.multipart.MultipartFile;
 
/**
 * description: Excel 数据导入
 * @version v1.0
 **/
public class ExcelImport {

    private ExcelImport INSTANSE = new ExcelImport();

    /**
     * excel 2003 suffix
     */
    private static final String EXCEL_XLS_SUFFIX = ".xls";

    /**
     * excel 2007 或以上 suffix
     */
    private static final String EXCEL_XLSX_SUFFIX = ".xlsx";

    /**
     * 分隔符 "."
     */
    public static final String POINT = ".";

    /**
     * description: 读取excel数据
     *
     * @param file
     * @return List<List < Object>>
     * @version v1.0
     */
    public static List<List<Object>> importFile(File file) throws Exception {
        if (file == null) {
            return null;
        }
        if (file.getName().endsWith(EXCEL_XLS_SUFFIX)) {
            return readXls(new FileInputStream(file));
        }
        if (file.getName().endsWith(EXCEL_XLSX_SUFFIX)) {
            return readXlsx(new FileInputStream(file));
        }
        throw new RuntimeException("文件不对,必须是excel文件，后缀名以：" + EXCEL_XLS_SUFFIX + " 或者 " + EXCEL_XLSX_SUFFIX);
    }

    /**
     * description: 导入excel --- 支持web
     *
     * @return List<List < Object>>
     * @throws Exception
     * @version v1.0
     */
    public static List<List<Object>> importFile(MultipartFile multipartFile) throws Exception {
        if (multipartFile == null) {
            return null;
        }
        if (multipartFile.getOriginalFilename().endsWith(EXCEL_XLS_SUFFIX)) {
            return readXls(multipartFile.getInputStream());
        }
        if (multipartFile.getOriginalFilename().endsWith(EXCEL_XLSX_SUFFIX)) {
            return readXlsx(multipartFile.getInputStream());
        }
        throw new RuntimeException("文件不对,必须是excel文件，后缀名以：" + EXCEL_XLS_SUFFIX + " 或者 " + EXCEL_XLSX_SUFFIX);
    }


    /**
     * description: 读取03版excel
     *
     * @return List<List < Object>>
     * @version v1.0
     */
    private static List<List<Object>> readXls(InputStream inputStream) throws Exception {
        List<List<Object>> list = new ArrayList<>();
        // 读取excel 
        HSSFWorkbook workbook = new HSSFWorkbook(inputStream);
        // 获取sheet 页数量
        int sheets = workbook.getNumberOfSheets();
        for (int num = 0; num < sheets; num++) {
            HSSFSheet sheet = workbook.getSheetAt(num);
            if (null == sheet) {
                continue;
            }
            // sheet 页的总行数
            int rows = sheet.getLastRowNum();
            // startRow 开始读取的行数 --- 第二行开始读
            for (int startRow = 1; startRow <= rows; startRow++) {
                HSSFRow row = sheet.getRow(startRow);
                List<Object> rowList = new ArrayList<>();
                if (null != row) {
                    // row 行中的 单元格总个数
                    short cells = row.getLastCellNum();
                    for (int x = 0; x <= cells; x++) {
                        HSSFCell cell = row.getCell(x);
                        if (null == cell) {
                            rowList.add("");
                        } else {
                            rowList.add(getXlsValue(cell));
                        }
                    }
                    list.add(rowList);
                }
            }
        }
        return list;
    }

    /**
     * description: 获取 03 版 excel数据
     *
     * @param cell
     * @return String
     * @version v1.0
     */
    private static String getXlsValue(HSSFCell cell) {
        if (cell.getCellType() == cell.CELL_TYPE_BOOLEAN) {
            return String.valueOf(cell.getBooleanCellValue());
        } else if (cell.getCellType() == cell.CELL_TYPE_NUMERIC) {
            String cellValue = "";
            if (HSSFDateUtil.isCellDateFormatted(cell)) {
                Date date = HSSFDateUtil.getJavaDate(cell.getNumericCellValue());
                cellValue = new SimpleDateFormat("yyyy/MM/dd").format(date);
            } else {
                DecimalFormat df = new DecimalFormat("#.##");
                cellValue = df.format(cell.getNumericCellValue());
                String strArr = cellValue.substring(cellValue.lastIndexOf(POINT) + 1, cellValue.length());
                if (strArr.equals("00")) {
                    cellValue = cellValue.substring(0, cellValue.lastIndexOf(POINT));
                }
            }
            return cellValue;
        } else {
            // 其他类型的值，统一设置为 string
            // http://blog.csdn.net/ysughw/article/details/9288307
            cell.setCellType(Cell.CELL_TYPE_STRING);
            return String.valueOf(cell.getStringCellValue());
        }
    }

    /**
     * description: 读取07或以上版本的 excel
     *
     * @return List<List < Object>>
     * @throws Exception
     * @version v1.0
     */
    private static List<List<Object>> readXlsx(InputStream inputStream) throws Exception {
        List<List<Object>> list = new ArrayList<>();
        // 读取excel ，封装到 XSSFWorkbook 对象 
        XSSFWorkbook workbook = new XSSFWorkbook(inputStream);
        int sheets = workbook.getNumberOfSheets();
        for (int num = 0; num < sheets; num++) {
            XSSFSheet sheet = workbook.getSheetAt(num);
            if (null == sheet) {
                continue;
            }
            // 获取sheet页的总行数
            int rows = sheet.getLastRowNum();
            for (int startRow = 1; startRow <= rows; startRow++) {
                // startRow 开始读取的行数， 从第二行开始读取
                XSSFRow row = sheet.getRow(startRow);
                List<Object> rowList = new ArrayList<>();
                if (null != row) {
                    // 获取行总单元格个数
                    short cells = row.getLastCellNum();
                    for (int x = 0; x < cells; x++) {
                        XSSFCell cell = row.getCell(x);
                        if (cell == null) {
                            rowList.add("");
                        } else {
                            rowList.add(getXlsxValue(cell));
                        }
                    }
                    list.add(rowList);
                }
            }
        }
        return list;
    }

    /**
     * description: 获取07或以上版本 excel 数据
     *
     * @param cell
     * @return Object
     * @version v1.0
     */
    private static Object getXlsxValue(XSSFCell cell) {
        if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
            return String.valueOf(cell.getBooleanCellValue());
        } else if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
            String cellValue = "";
            if (DateUtil.isCellDateFormatted(cell)) {
                Date date = DateUtil.getJavaDate(cell.getNumericCellValue());
                cellValue = new SimpleDateFormat("yyyy/MM/dd").format(date);
            } else {
                DecimalFormat df = new DecimalFormat("#.##");
                cellValue = df.format(cell.getNumericCellValue());
                String strArr = cellValue.substring(cellValue.lastIndexOf(POINT) + 1, cellValue.length());
                if (strArr.equals("00")) {
                    cellValue = cellValue.substring(0, cellValue.lastIndexOf(POINT));
                }
            }
            return cellValue;
        } else {
            // 其他类型的值，统一设置为 string 
            // http://blog.csdn.net/ysughw/article/details/9288307
            //cell.setCellType(Cell.CELL_TYPE_STRING);
            return String.valueOf(cell.getStringCellValue());
        }
    }
}

@PostMapping("/getDataListExcel")
    @ApiOperation("解析excel")
    public String getDataListExcel(@RequestBody MultipartFile file) {
        try {
            List<List<Object>> lists = ExcelImport.importFile(file);
            System.out.println(lists);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "success";
    }