java 读取excel文件中经过公式算出的列值

我在读取excel表格的时候，发现明明好好的数值列，在某一行就是报错，debug了一下，发现那一列是经过公式算出来的 比如值是：=A1+B1+C1。 如果想要经过计算后的此列的值，就需要用到HSSFFormulaEvaluator.我参考的是在一个bbs上看到的：http://bbs.csdn.net/topics/340055433

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.CellValue;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import com.zkhy.web.integration.settle.entity.SettlePay;
import com.zkhy.web.presentation.settle.vo.PayAddressVO;

public class TestAnalyseExcel {

	@BeforeClass
	public static void setUpBeforeClass() throws Exception {
	}

	@AfterClass
	public static void tearDownAfterClass() throws Exception {
	}

	@Before
	public void setUp() throws Exception {
	}

	@After
	public void tearDown() throws Exception {
	}
	
	 HSSFWorkbook hssfWorkbook;
	
	HSSFFormulaEvaluator evaluator;
	   
    @Test
	public void testGetListFromExcel() throws IOException {
    	
    	
	InputStream is = new FileInputStream("D:\\file\\settle\\pay\\1435644172649socialSecurity_city.xls");
        HSSFWorkbook hssfWorkbook = new HSSFWorkbook(is);
       evaluator = new HSSFFormulaEvaluator();
        // 获取第一个工作表Sheet
        HSSFSheet hssfSheet = hssfWorkbook.getSheetAt(0);
        
        if (hssfSheet == null) {
        	throw new IOException("传入的excel的第一张表为空！");
        }

        List list = new ArrayList();
        
         HSSFRow hssfRow = hssfSheet.getRow(1);
            
        for (int rowNum = 2; rowNum <= hssfSheet.getLastRowNum(); rowNum++) {
        		
        		hssfRow = hssfSheet.getRow(rowNum);
        		SettlePay record = convertRowToSettlePay(hssfRow);
        		list.add(record);
         }
        	
	}
	

	private SettlePay convertRowToSettlePay(HSSFRow hssfRow) {
		 SettlePay record = new SettlePay();
		 for(int i=1;i

CellValue tempCellValue = evaluator.evaluate(hssfCell);
		double iCellValue = tempCellValue.getNumberValue(); 
return String.valueOf(iCellValue); 
}else if (hssfCell.getCellType() == hssfCell.CELL_TYPE_ERROR) { 
return null;
} else {
// 返回字符串类型的值 
return String.valueOf(hssfCell.getStringCellValue()); }}}