使用Apache POI更新Excel文件 [英] Updating excel file using Apache POI
本文介绍了使用Apache POI更新Excel文件的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在尝试使用Apache POI更新现有的excel文件.每次我运行代码时,都会收到如下所示的错误.我也尝试过FileInputStreamNewFile的事情.
I am trying to update an existing excel file using Apache POI. Every time I run my code I receive an error as shown below. I have also tried FileInputStreamNewFile thing.
Exception in thread "main" java.lang.NullPointerException
at com.gma.test.WriteExcelTest.writeXLSXFile(WriteExcelTest.java:26)
at com.gma.test.WriteExcelTest.main(WriteExcelTest.java:44)
请在下面找到代码.感谢您的帮助.
Please find the code below. Appreciate your help.
package com.gma.test;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class WriteExcelTest {
public static void writeXLSXFile(int row, int col) throws IOException {
try {
FileInputStream file = new FileInputStream("C:\\Anuj\\Data\\Data.xlsx");
XSSFWorkbook workbook = new XSSFWorkbook(file);
XSSFSheet sheet = workbook.getSheetAt(0);
Cell cell = null;
//Update the value of cell
cell = sheet.getRow(row).getCell(col);
cell.setCellValue("Pass");
file.close();
FileOutputStream outFile =new FileOutputStream(new File("C:\\Anuj\\Data\\Data.xlsx"));
workbook.write(outFile);
outFile.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
writeXLSXFile(3, 3);
}
}
推荐答案
如果替换
//Update the value of cell
cell = sheet.getRow(row).getCell(col);
cell.setCellValue("Pass");
使用
//Retrieve the row and check for null
HSSFRow sheetrow = sheet.getRow(row);
if(sheetrow == null){
sheetrow = sheet.createRow(row);
}
//Update the value of cell
cell = sheetrow.getCell(col);
if(cell == null){
cell = sheetrow.createCell(col);
}
cell.setCellValue("Pass");
它将起作用!
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