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java – While reading data from Excel Sheet got NullpointerException

Posted by: admin May 14, 2020 Leave a comment

Questions:

I am trying to read data from a excel sheet but getting NullPointerException every time when reading data at the cell index =6. Put while(value != null) to avoid null values but still got the exception without any output.
I am putting the screen shot of excel sheet from where i am trying to get data. enter image description here

Code-
package com.selenium;

import java.io.FileInputStream;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.usermodel.WorkbookFactory;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.firefox.FirefoxDriver;
import java.io.IOException;

public class Exxcel {
  public static void main(String[] args) throws Exception,NullPointerException{
    //WebDriver driver= new FirefoxDriver();
    //WebElement wb;
    try{
    FileInputStream file= new FileInputStream("C:\Documents and Settings\OMEGA\Desktop\Test Planning And Documents\Automation Data.xlsx");
    Workbook data=WorkbookFactory.create(file);
    Sheet sheet=data.getSheet("Sheet1");
    for(int i=1;i<=sheet.getLastRowNum();i++){
        Row row= sheet.getRow(i);
        int j=0;
        String value=row.getCell(j).getStringCellValue();
        while(value != null){ 
        System.out.println(value);
        }//while
        while(value == null){
            j++; 
         }  
    }//for

         /*while(j1==9){
             String value=row.getCell(j1).getStringCellValue();
             System.out.println(value);
             }//while2
             */
    }catch(NullPointerException n){n.printStackTrace();
        System.out.println("Null");
        }// catch
    }//main
 }//class


StackTrace-
Null
java.lang.NullPointerException
at com.selenium.Exxcel.main(Exxcel.java:22)
How to&Answers:

It’s not enough to check that row.getCell(j).getStringCellValue() != null. You should check that row.getCell(j) != null.

In addition, your while loops makes no sense :

The first one will either do nothing or print value forever (since you are not changing value inside the loop).

    while(value != null) { 
        System.out.println(value);
    }//while

The second one will either do nothing or increment j forever (since you are not changing value inside the loop).

    while(value == null) {
        j++; 
    } 

I suggest you replace them with the following code :

Row row = sheet.getRow(i);
if (row != null) {
    for (int j = 0; j < row.getLastCellNum(); j++) {
        if (row.getCell(j) != null) {
            if (row.getCell(j).getCellType() == CELL_TYPE_STRING) {
                String value=row.getCell(j).getStringCellValue();
                if(value != null) { 
                    System.out.println(value);
                }
            }
        }   
    }
}