controller层： 通过文件流的方式 读取 前端上传的文件 MultipartFile 

上传文件：utf-8编码的csv文件

    @ApiOperation(value = "导入文件")
    @RequestMapping(value = "/updateFieldMapFromCsvfile", method = RequestMethod.POST)
    public BaseResult updateFieldMapFromCsvfile(@RequestParam("file") MultipartFile multipartFile) throws IOException, ParseException {
        BaseResult baseResult = new BaseResult();
        BaseController.execute(null, new ControllerCallback<Long>() {
            @Override
            public void check() {
            }
            @Override
            public Long execute() throws IOException {
                // 更新
                return nodeService.updateFieldMapFromCsvfile(multipartFile);
            }
        }, baseResult);
        return baseResult;

    }

实现层：

   public long updateFieldMapFromCsvfile(MultipartFile multipartFile) throws IOException {
        Reader reader = new InputStreamReader(multipartFile.getInputStream(), "UTF-8");
        BufferedReader br = new BufferedReader(reader);
        br.readLine();//br是迭代器类型的，每readline一次，行数指向next，用于过滤第0行标题
        String line ;
        while ((line = br.readLine()) != null) {
            SqDataNodeFieldMapDO eachData = new SqDataNodeFieldMapDO();
            String item[] = line.split(",");
            eachData.setId(Long.parseLong(item[0]));
            eachData.setOutputNode(item[3]);
            eachData.setOutputField(item[4]);
            eachData.setOutputValueType(item[5]);
            eachData.setSourceNode(item[6]);
            eachData.setSourceField(item[7]);
            eachData.setSourceValueType(item[8]);
            eachData.setLastModer(item[9]);
            eachData.setLinkCode(item[10]);
            eachData.setBizCode(item[11]);
            eachData.setValueUdf(item[12]);
            eachData.setValueCaliber(item[13]);
            fieldMapConfigService.updateFieldMapFromCsv(eachData);//更新数据库
        }
        return 0;
    }

postman调用调试