String fileSuffix = file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf(".")); //获取文件的后缀名.excl
XSSFWorkbook xssfWorkBook=XSSFWorkbookKit.create(file.getInputStream());
XSSFSheet xssfSheet = xssfWorkBook.getSheetAt(0);
String sheetName = xssfSheet.getSheetName();//sheet名称,用于校验模板是否正确