Java 使用 Apache POI 更新 excel 文件
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时间：2020-08-11 12:16:05 来源:igfitidea点击:
Updating excel file using Apache POI
提问by Anuj Shrivastav
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.
我正在尝试使用 Apache POI 更新现有的 excel 文件。每次运行我的代码时，都会收到如下所示的错误。我也试过 FileInputStreamNewFile 的事情。
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)
Please find the code below. Appreciate your help.
请在下面找到代码。感谢你的帮助。
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);
}
}
采纳答案by Jelle Heuzel
If you replace
如果你更换
//Update the value of cell
cell = sheet.getRow(row).getCell(col);
cell.setCellValue("Pass");
With
和
//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");
It will work!
它会起作用！
回答by turoni
Thanks Jelle Heuzel for getting a good example.
I just wanted to add the resulting working code so other can incorporate it in their code faster.
感谢 Jelle Heuzel 提供了一个很好的例子。
我只是想添加生成的工作代码，以便其他人可以更快地将其合并到他们的代码中。
I also had to use XSSFRow instead of HSSFRow but other than that it works fine for me.
我还必须使用 XSSFRow 而不是 HSSFRow 但除此之外它对我来说很好用。
package stackoverflow.appachePOI;
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.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:\Users\Sam\files\Masterproef lca\lca-analysebeheer\Test-Files\exceltemplates\template.xlsx");
XSSFWorkbook workbook = new XSSFWorkbook(file);
XSSFSheet sheet = workbook.getSheetAt(0);
Cell cell = null;
//Retrieve the row and check for null
XSSFRow 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");
file.close();
FileOutputStream outFile =new FileOutputStream(new File("C:\Users\Sam\files\Masterproef lca\lca-analysebeheer\Test-Files\exceltemplates\Output.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);
}
}
回答by diego matos - keke
i tried with this and work for XLSX and XSSF
我试过这个并为 XLSX 和 XSSF 工作
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.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class TestStackOver {
public static void writeXLSXFile(int row, int col) throws IOException {
try {
FileInputStream file = new FileInputStream(Constante.ruta);
XSSFWorkbook workbook = new XSSFWorkbook(file);
XSSFSheet sheet = workbook.getSheetAt(0);
Cell cell = null;
//Retrieve the row and check for null
XSSFRow 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");
file.close();
FileOutputStream outFile =new FileOutputStream(new File(Constante.ruta_salida));
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
System.out.println("inicio");
writeXLSXFile(1, 14);
System.out.println("terminado");
}
}
