Excel导入工具类兼容xls和xlsx

package com.bj58.finance.platform.operation.provider.util;

import org.apache.log4j.Logger;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.util.IOUtils;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.mock.web.MockMultipartFile;
import org.springframework.web.multipart.MultipartFile;

import java.io.*;
import java.util.ArrayList;
import java.util.List;

/**
 * excel读写工具类
 */
public class POIUtil {
    private static Logger logger = Logger.getLogger(POIUtil.class);
    private final static String xls = "xls";
    private final static String xlsx = "xlsx";

    /**
     * 读入excel文件，解析后返回
     *
     * @param file
     * @throws IOException
     */
    public static List<String[]> readExcel(MultipartFile file) throws IOException {
        //检查文件
        checkFile(file);
        //获得Workbook工作薄对象
        Workbook workbook = getWorkBook(file);
        //创建返回对象，把每行中的值作为一个数组，所有行作为一个集合返回
        List<String[]> list = new ArrayList<String[]>();
        if (workbook != null) {
            for (int sheetNum = 0; sheetNum < workbook.getNumberOfSheets(); sheetNum++) {
                //获得当前sheet工作表
                Sheet sheet = workbook.getSheetAt(sheetNum);
                if (sheet == null) {
                    continue;
                }
                //获得当前sheet的开始行
                int firstRowNum = sheet.getFirstRowNum();
                //获得当前sheet的结束行
                int lastRowNum = sheet.getLastRowNum();
                //循环除了第一行的所有行
                for (int rowNum = firstRowNum + 1; rowNum <= lastRowNum; rowNum++) {
                    //获得当前行
                    Row row = sheet.getRow(rowNum);
                    if (row == null) {
                        continue;
                    }
                    //获得当前行的开始列
                    int firstCellNum = row.getFirstCellNum();
                    //获得当前行的列数
                    int lastCellNum = row.getPhysicalNumberOfCells();
                    String[] cells = new String[row.getPhysicalNumberOfCells()];
                    //循环当前行
                    for (int cellNum = firstCellNum; cellNum < lastCellNum; cellNum++) {
                        Cell cell = row.getCell(cellNum);
                        cells[cellNum] = getCellValue(cell);
                    }
                    list.add(cells);
                }
            }
            workbook.close();
        }
        return list;
    }

    public static void checkFile(MultipartFile file) throws IOException {
        //判断文件是否存在
        if (null == file) {
            logger.error("文件不存在！");
            throw new FileNotFoundException("文件不存在！");
        }
        //获得文件名
        String fileName = file.getOriginalFilename();
        //判断文件是否是excel文件
        if (!fileName.endsWith(xls) && !fileName.endsWith(xlsx)) {
            logger.error(fileName + "不是excel文件");
            throw new IOException(fileName + "不是excel文件");
        }
    }

    public static Workbook getWorkBook(MultipartFile file) {
        //获得文件名
        String fileName = file.getOriginalFilename();
        //创建Workbook工作薄对象，表示整个excel
        Workbook workbook = null;
        try {
            //获取excel文件的io流
            InputStream is = file.getInputStream();
            //根据文件后缀名不同(xls和xlsx)获得不同的Workbook实现类对象
            if (fileName.endsWith(xls)) {
                //2003
                workbook = new HSSFWorkbook(is);
            } else if (fileName.endsWith(xlsx)) {
                //2007
                workbook = new XSSFWorkbook(is);
            }
        } catch (IOException e) {
            logger.info(e.getMessage());
        }
        return workbook;
    }

    public static String getCellValue(Cell cell) {
        String cellValue = "";
        if (cell == null) {
            return cellValue;
        }
        //把数字当成String来读，避免出现1读成1.0的情况
        if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
            cell.setCellType(Cell.CELL_TYPE_STRING);
        }
        //判断数据的类型
        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_NUMERIC: //数字
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            case Cell.CELL_TYPE_STRING: //字符串
                cellValue = String.valueOf(cell.getStringCellValue());
                break;
            case Cell.CELL_TYPE_BOOLEAN: //Boolean
                cellValue = String.valueOf(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_FORMULA: //公式
                cellValue = String.valueOf(cell.getCellFormula());
                break;
            case Cell.CELL_TYPE_BLANK: //空值
                cellValue = "";
                break;
            case Cell.CELL_TYPE_ERROR: //故障
                cellValue = "非法字符";
                break;
            default:
                cellValue = "未知类型";
                break;
        }
        return cellValue;
    }

    public static void main(String[] args) {

        File file = new File("D://新增产品支持的银行列表模板.xlsx");
        FileInputStream input = null;
        try {
            input = new FileInputStream(file);
            MultipartFile multipartFile = new MockMultipartFile("file", file.getName(), "text/plain", IOUtils.toByteArray(input));
            List<String[]> list = readExcel(multipartFile);
            System.out.println(list);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

需要引入的Maven依赖：

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.14</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.14</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>4.2.5.RELEASE</version>
        </dependency>

原文地址：https://www.cnblogs.com/lxcmyf/p/9965779.html