String cellValue = "";

                double numericCellValue = cell.getNumericCellValue();

                BigDecimal bd2 = new BigDecimal(String.valueOf(numericCellValue)).setScale(6, BigDecimal.ROUND_HALF_UP);

                cellValue = bd2.stripTrailingZeros().toPlainString();


            return cellValue;

stripTrailingZeros是小数点后最后的0全部去除