java导入xls和xlsx格式

            InputStream inputStream = new BufferedInputStream(new FileInputStream(file));             Sheet sheet = null;            //读写xls和xlsx格式时，HSSFWorkbook针对xls，XSSFWorkbook针对xlsx            if (POIFSFileSystem.hasPOIFSHeader(inputStream)) {                HSSFWorkbook workBook = new HSSFWorkbook(new BufferedInputStream(inputStream));                sheet = workBook.getSheetAt(0);            }else{                XSSFWorkbook workBook = new XSSFWorkbook(new BufferedInputStream(inputStream));                sheet = workBook.getSheetAt(0);            }