POI获取excel中函数计算所得的值

import org.apache.poi.ss.usermodel.Cell;

import org.apache.poi.ss.usermodel.CellValue;

import org.apache.poi.ss.usermodel.FormulaEvaluator;

import org.apache.poi.ss.usermodel.Row;

import org.apache.poi.ss.usermodel.Sheet;

import org.apache.poi.ss.usermodel.Workbook;

import org.apache.poi.xssf.usermodel.XSSFWorkbook;

Workbook wb=new XSSFWorkbook();

Sheet sheet = wb.createSheet();

Row row = sheet.createRow(0);

Cell cell0 = row.createCell(0);

Cell cell1 = row.createCell(1);

Cell cell2 = row.createCell(2);

cell0.setCellValue(2);

cell1.setCellValue(2);

cell2.setCellType(Cell.CELL_TYPE_FORMULA);

cell2.setCellFormula("SUM(A1+B1)");

FormulaEvaluator evaluator = wb.getCreationHelper().createFormulaEvaluator();

evaluator.evaluateFormulaCell(cell2);

CellValue cellValue = evaluator.evaluate(cell2);

System.out.println(cellValue.getNumberValue());