java poi 怎样得到公式计算后的数值?怎样得到计算公式?

 

 switch (cell.getCellType()) {
            case Cell.CELL_TYPE_NUMERIC: //数字
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            case Cell.CELL_TYPE_STRING: //字符串
                cellValue = String.valueOf(cell.getStringCellValue());
                break;
            case Cell.CELL_TYPE_BOOLEAN: //Boolean
                cellValue = String.valueOf(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_FORMULA: //公式
                //cellValue = String.valueOf(cell.getCellFormula());  //直接获得公式
                cellValue = String.valueOf(cell.getNumericCellValue());  //获得公式计算后的值
                break;
            case Cell.CELL_TYPE_BLANK: //空值
                cellValue = "0";
                break;
            case Cell.CELL_TYPE_ERROR: //故障
                cellValue = "非法字符";
                break;
            default:
                cellValue = "未知类型";
                break;
        }