EasyExcel相较于传统Excel操作或者解析都是利用Apach POI进行操作,EasyExcel更加便捷,少了很多繁琐步骤
https://easyexcel.opensource.alibaba.com/docs/current/

依赖

        <!-- https://mvnrepository.com/artifact/com.alibaba/easyexcel -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>3.0.5</version>
        </dependency>

/**
 * 基础数据类
 *
 * @author Jiaju Zhuang
 **/
@Getter
@Setter
@EqualsAndHashCode
public class DownloadData {
    //value 对应标题 index 对应列的顺序 一般用在文件下载上
    @ExcelProperty(value = "字符串标题",index =0)
    private String string;
    @ExcelProperty(value = "日期标题",index =1)
    private Date date;
    @ExcelProperty(value = "数字标题",index =2)
    private Double doubleData;
    // @ExcelIgnore 注解用来注释需要忽略类中不需要处理的字段
    @ExcelIgnore
    private String test;

}

文件下载

        /**
     * 文件下载（失败了会返回一个有部分数据的Excel）
     * <p>
     * 1. 创建excel对应的实体对象 参照{@link DownloadData}
     * <p>
     * 2. 设置返回的 参数
     * <p>
     * 3. 直接写，这里注意，finish的时候会自动关闭OutputStream,当然你外面再关闭流问题不大
     */
    @PostMapping("/exportDetail")
    public void exportDetail(HttpServletResponse response) throws LogicalException, IOException {
         //查询需要导出的数据集合
        List<DownloadData> list = tenantCarService.exportDetail();
        // 这里注意 有同学反应使用swagger 会导致各种问题，请直接用浏览器或者用postman
        try {
            //设置头居中
            WriteCellStyle headWriteCellStyle = new WriteCellStyle();
            headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
            //设置内容居中
            WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
            contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);

            HorizontalCellStyleStrategy horizontalCellStyleStrategy = new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            response.setCharacterEncoding("utf-8");
            String fileName = URLEncoder.encode("文件名称", "UTF-8");
            response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".xlsx");
            EasyExcel.write(response.getOutputStream(), DownloadData .class)
                    .autoCloseStream(Boolean.FALSE)
                    .registerWriteHandler(horizontalCellStyleStrategy)
                    .sheet("模板")
                    //要导出的数据集合
                    .doWrite(list);
        } catch (Exception e) {
            // 重置response
            response.reset();
            response.setContentType("application/json");
            response.setCharacterEncoding("utf-8");
            Map<String, String> map = MapUtils.newHashMap();
            map.put("status", "failure");
            map.put("message", "下载文件失败" + e.getMessage());
            response.getWriter().println(JSON.toJSONString(map));
        }
  }      

文件上传

/**
 * 基础数据类
 *
 * @author Jiaju Zhuang
 **/
@Getter
@Setter
@EqualsAndHashCode
public class UploadData {
    //value 对应标题 index 对应列的顺序 一般用在文件下载上
    @ExcelProperty(value = "字符串标题",index =0)
    private String string;
    @ExcelProperty(value = "日期标题",index =1)
    private Date date;
    @ExcelProperty(value = "数字标题",index =2)
    private Double doubleData;
}

    /**
     * 文件上传
     * <p>
     * 1. 创建excel对应的实体对象 参照{@link UploadData}
     * <p>
     * 2. 由于默认一行行的读取excel，所以需要创建excel一行一行的回调监听器，参照{@link UploadDataListener}
     * <p>
     * 3. 直接读即可
     */
    @PostMapping("upload")
    @ResponseBody
    public String upload(MultipartFile file) throws IOException {
        List<UploadData> list = EasyExcel.read(new BufferedInputStream(file.getInputStream())).head(UploadData.class).sheet().doReadSync();
        //之后做入库操作
        //  .....
        return "success";
    }