Springboot/SpringMvc 讀取上傳 xls 文件內容

/** * 讀取上傳 xls 內容返回 * @param file * @return */@RequestMapping(value = "/read.xls")@ResponseBodypublic String read(@RequestParam("file") MultipartFile file) {    //判斷上傳的文件類型是否是圖片    int maxSize = 1024 * 1024 * 2;    if (file == null || file.getSize()> maxSize){        object.put("msg","上傳文件 不能爲空/不能大於2M");    }else{        StringBuffer phones = new StringBuffer();        try {            Workbook wb = WorkbookFactory.create(file.getInputStream());            Sheet sheet = wb.getSheetAt(0);// 第一個腳本下的            logger.info(sheet.toString());            sheet.forEach(e->{                e.forEach(e1->{                    e1.setCellType(Cell.CELL_TYPE_STRING);                    phones.append(e1.getStringCellValue() + ",");                });            });        } catch (Exception e) {            e.printStackTrace();        }        if(phones.length()>0){            phones.delete(phones.length()-1,phones.length());        }    }    return phones.toString();}