Apache POI XSSFWorkbook throwing NullPointerException for file

Question

I have checked every possible question on here with a similar problem, and none of the solutions have worked. I feel like I am missing something really obvious, but I just c

Answer 1

I think you have not added the jars properly.

First go to this url : https://archive.apache.org/dist/poi/release/bin/ and download poi-bin-4.1.2-20200217.zip from there.

Now extract the zip and add this jars to your project marked with red.

I have tested your code and its working.

import java.io.File;
import java.io.IOException;
import java.util.Iterator;

import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class Testing {
    public static void main(String args[]) throws IOException, InvalidFormatException {

        // Linking file to Workbook
        // ****Where exception is called every time****
        XSSFWorkbook wb = new XSSFWorkbook(new File("C:\\Users\\Anish\\Downloads\\TestData.xlsx"));

        System.out.println("Workbook loaded");

        // Pulling sheet from Workbook
        XSSFSheet sheet = wb.getSheetAt(0);

        // Get iterator to all the rows in current sheet
        Iterator<Row> rowIterator = sheet.iterator();

        // Traversing over each row of XLSX file
        while (rowIterator.hasNext()) {
            Row row = rowIterator.next();

            // For each row, iterate through each columns
            Iterator<Cell> cellIterator = row.cellIterator();

            while (cellIterator.hasNext()) {
                Cell cell = cellIterator.next();
                switch (cell.getCellType()) {
                case STRING:
                    System.out.print(cell.getStringCellValue() + "\t");
                    break;
                case NUMERIC:
                    System.out.print(cell.getNumericCellValue() + "\t");
                    break;
                case BOOLEAN:
                    System.out.print(cell.getBooleanCellValue() + "\t");
                    break;
                default:
                }
            }
        }
        wb.close();

    }
}

Output :

Now, if you are using maven in the project.Then, you don't need to add jars on the classpath.

Simply, add this dependency in the pom.xml.

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.2</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

Answer 2

So after much troubleshoooting, I abandoned using the Apache POI jar files, and switched to using maven and adding apache poi as a dependancy, and my code now runs successfully.

Thank you too everyone who helped and made suggestions, though I am still not sure of the origin of the communication problem between Eclipse and the POI jar files.