Question

要使用POI和java从excel文件中读取列，请执行以下操作：

package main;

import java.io.FileInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class ReadExcel {

 public static void main(String[] args) {

try {

    InputStream fs = new FileInputStream("/.../ListProducts.xls");
    HSSFWorkbook wb = new HSSFWorkbook(fs);
    HSSFSheet sheet = wb.getSheetAt(0);



    Map<String, Integer> map = new HashMap<String,Integer>(); //Create map
    HSSFRow row = sheet.getRow(0); //Get first row
    //following is boilerplate from the java doc
    short minColIx = row.getFirstCellNum(); //get the first column index for a row
    short maxColIx = row.getLastCellNum(); //get the last column index for a row
    for(short colIx=minColIx; colIx<maxColIx; colIx++) { //loop from first to last index
    HSSFCell cell = row.getCell(colIx); //get the cell
    map.put(cell.getStringCellValue(),cell.getColumnIndex()); //add the cell contents (name of column) and cell index to the map
    }

    List<ReportRow> listOfDataFromReport = new ArrayList<ReportRow>();
    for(int x = 1; x<=sheet.getPhysicalNumberOfRows(); x++){
     ReportRow rr = new ReportRow(); 
     HSSFRow dataRow = sheet.getRow(x); 

     int idxForColumn1 = map.get("Id"); 
     int idxForColumn2 = map.get("Name"); 
     int idxForColumn3 = map.get("Price"); 

     HSSFCell cell1 = dataRow.getCell(idxForColumn1); 
     HSSFCell cell2 = dataRow.getCell(idxForColumn2); 
     HSSFCell cell3 = dataRow.getCell(idxForColumn3);  

     rr.setColumn1(cell1.getNumericCellValue()); 
     rr.setColumn2(cell2.getNumericCellValue());
     rr.setColumn3(cell3.getNumericCellValue());

     listOfDataFromReport.add(rr);

    }

} catch (Exception e) {
    System.out.println(e.getMessage());
}
}

我注意到setColumn1,setColumn2,setColumn3方法的变量是double。

当我尝试运行程序来读取数据时出现以下错误：

     Exception in thread "main" java.lang.IllegalStateException: Cannot get a NUMERIC value from a STRING cell
at org.apache.poi.hssf.usermodel.HSSFCell.typeMismatch(HSSFCell.java:654)
at org.apache.poi.hssf.usermodel.HSSFCell.getNumericCellValue(HSSFCell.java:679)

请给我任何建议，我在excel文件中有一个数字类型的所有单元格......

Answer 1

您要做的是使用DataFormatter类。你传递了一个单元格，它会尽力返回一个字符串，其中包含Excel为该单元格显示的内容。如果你传递一个字符串单元格，你将获得该字符串。如果您传递了一个应用了格式规则的数字单元格，它将根据它们格式化数字并返回字符串。

对于您的情况，如果您要求DataFormatter格式化这些单元格，它会返回一个包含双字符串的字符串。

尝试使用

DataFormatter formatter = new DataFormatter();
String str = formatter.formatCellValue(cell1);
double dnum = Double.parseDouble(str );
System.out.println("In formated Cell Value--" + dnum);
rr.setColumn1(dnum);

如需更多参考，请查看这些链接，我认为它会对您有所帮助。 http://massapi.com/class/da/DataFormatter.html

Answer 2

如果您确定3个值是数字，则可以在读取之前修改它的类型：

HSSFCell cell1 = dataRow.getCell(idxForColumn1); 
HSSFCell cell2 = dataRow.getCell(idxForColumn2); 
HSSFCell cell3 = dataRow.getCell(idxForColumn3);  

cell1.setCellType(CellType.NUMERIC);
cell2.setCellType(CellType.NUMERIC);
cell3.setCellType(CellType.NUMERIC);

rr.setColumn1(cell1.getNumericCellValue()); 
rr.setColumn2(cell2.getNumericCellValue());
rr.setColumn3(cell3.getNumericCellValue());

无法从带有POI的STRING单元格获取NUMERIC值

2 个答案: