实例代码：

    @PostMapping("/import")
    public ResponseMsg<Boolean> importConfig(@RequestBody MultipartFile file ) {
        try {
            ExcelReader reader = ExcelUtil.getReader(file.getInputStream());
            reader.addHeaderAlias("标题行名称","对应的字段");
            //例如
            reader.addHeaderAlias("用户名","username");
            List<User> list = reader.readAll(User.class);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

引入hutool依赖 hutool依赖版本会影响部分方法的使用，在最新的版本中更新了很多4.x版本不同的方法

<!-- hutool 工具包 -->
<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.8.1</version>
</dependency>

<!-- poi exce表格导入导出 -->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

<!-- poi需要使用 excel表格解析器 -->
<dependency>
    <groupId>xerces</groupId>
    <artifactId>xercesImpl</artifactId>
    <version>2.11.0</version>
</dependency>

流式读取

@PostMapping("/excel")
public String importBatchExcel(@RequestBody MultipartFile file) throws Exception {
    List<Map<String,String>> lists = new LinkedList<>();
    List<Object> lists2 = new LinkedList<>();
    Workbook workbook=null;

    boolean is2003Excel= file.getOriginalFilename().toLowerCase().endsWith("xls")?true:false;
    if (is2003Excel){
        workbook= new HSSFWorkbook(file.getInputStream());
    }else {
        workbook = new XSSFWorkbook(file.getInputStream());
    }
    // sheet页数
    int numberOfSheets = workbook.getNumberOfSheets();

    for (int i=0;i<numberOfSheets;i++){
        //读取每一个sheet
        Sheet sheetAt = workbook.getSheetAt(i);
        for (Row row: sheetAt){
            //每一行 第几列
            System.out.println(row.getCell(0));
        }   
    }

提出来一个静态方法

public static  void getExcel(MultipartFile file) throws Exception {
    HSSFWorkbook workbook = new HSSFWorkbook(file.getInputStream());

    HSSFSheet sheet = null;
    for (int i = 0; i < workbook.getNumberOfSheets(); i++) {//获取每个Sheet表
        sheet = workbook.getSheetAt(i);
        System.out.println(sheet.getSheetName());
        for (int j = 0; j < sheet.getPhysicalNumberOfRows(); j++) {//获取每行
            HSSFRow row = sheet.getRow(j);

            for (int k = 0; k < row.getPhysicalNumberOfCells(); k++) {//获取每个单元格
                System.out.print(row.getCell(k) + "\t");
            }
            System.out.println("---Sheet" + i + "处理完毕---");
        }
    }
}

实际中的代码

        ResponseMsg<Boolean> msg = new ResponseMsg(ResponseCode.SUCCESS);
        List<Invoice> list = new ArrayList<>();
        List<InvoiceDetail> detailList = new ArrayList<>();
        try {
            OPCPackage opcPackage = OPCPackage.open(file.getInputStream());
            XSSFReader reader = new XSSFReader(opcPackage);
            // sheet页数
            SharedStringsTable sharedStringsTable = reader.getSharedStringsTable();
            StylesTable stylesTable = reader.getStylesTable();
//            SAXParserFactory parserFactory = SAXParserFactory.newInstance();
//            SAXParser parser = parserFactory.newSAXParser();
            XMLReader xmlReader = XMLReaderFactory.createXMLReader();
            XSSFReader.SheetIterator sheetIterator = (XSSFReader.SheetIterator) reader.getSheetsData();
            SheetHandler sheetHandler = new SheetHandler(list);
            SheetHandlerDetail sheetHandlerDetail = new SheetHandlerDetail(detailList);
            XSSFSheetXMLHandler sheetXMLHandler = new XSSFSheetXMLHandler(stylesTable, sharedStringsTable, sheetHandler, false);
            xmlReader.setContentHandler(sheetXMLHandler);
            while (sheetIterator.hasNext()) {
                InputStream next = sheetIterator.next();
                InputSource is = new InputSource(next);
                System.out.println("====sheetName1===");
                System.out.println(sheetIterator.getSheetName());
                System.out.println("====sheetName2===");
                log.info("读取"+sheetIterator.getSheetName());
                xmlReader.parse(is);
            }

新建一个SheetHandler类实现XSSFSheetXMLHandler.SheetContentsHandler接口

public class SheetHandler implements XSSFSheetXMLHandler.SheetContentsHandler {
     /**
     * 开始行
     * @param i
     */
    @Override
    public void startRow(int i) {

    }

    /**
     * 结束行
     * @param i
     */
    @Override
    public void endRow(int i) {

    }

    /**
     * 处理每个单元格
     * @param cellName
     * @param value
     * @param xssfComment
     */
    @SneakyThrows
    @Override
    public void cell(String cellName, String value, XSSFComment xssfComment) {

    }
}