How to read values from excel file and store in Array?

import java.io.File;
import java.io.IOException;

import jxl.Cell;
import jxl.Sheet;
import jxl.Workbook;
import jxl.read.biff.BiffException;

public class NewExcel 
{

    private String inputFile;
    String[][] data = null;
    public void setInputFile(String inputFile) 
    {
        this.inputFile = inputFile;
    }

    public String[][] read() throws IOException  
    {
        File inputWorkbook = new File(inputFile);
        Workbook w;

        try 
        {
            w = Workbook.getWorkbook(inputWorkbook);
            // Get the first sheet


            Sheet sheet = w.getSheet(0);
            data = new String[sheet.getColumns()][sheet.getRows()];
            // Loop over first 10 column and lines
       //     System.out.println(sheet.getColumns() +  " " +sheet.getRows());
            for (int j = 0; j <sheet.getColumns(); j++) 
            {
                for (int i = 0; i < sheet.getRows(); i++) 
                {
                    Cell cell = sheet.getCell(j, i);
                    data[j][i] = cell.getContents();
                  //  System.out.println(cell.getContents());
                }
            }

         /*   for (int j = 0; j < data.length; j++) 
            {
                for (int i = 0; i <data[j].length; i++) 
                {

                    System.out.println(data[j][i]);
                }
            } */

        } 
        catch (BiffException e) 
        {
            e.printStackTrace();
        }
    return data;
    }


}

If you really want an array, you are going to have to know how many elements you want in the array when you allocate storage for it. You can do that at runtime -- it does not have to be known at compile time -- but you have to do that before you can use the array.

Somewhere in a declarations section:

String[] dataArray = null;

and then somewhere in the code

dataArray = new String[numberOfElements];

You can make a two (or more) dimensional array on the same principle. After that, you can assign a string to any element of the array at an index less than numberOfElements.

package Utilities;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExcellReading {

    // public Workbook workbook= null;
    // public Sheet firstSheet= null;

    public String INPUT_XLS = "/ExcelManipulation/TestExecution.xlsx";

    public ExcellReading() {
    }

    public ExcellReading(String filepath) {
        INPUT_XLS = filepath;
    }

    public Map<Integer, List<String>> ReadExcel() throws IOException {

        FileInputStream inputStream = new FileInputStream(new File("TestExecution.xlsx"));

        Map<Integer, List<String>> data = new HashMap<Integer, List<String>>();

        Workbook workbook = new XSSFWorkbook(inputStream);

        Sheet firstSheet = workbook.getSheetAt(5);

        Iterator<Row> iterator = firstSheet.iterator();

        // Test test=new Test();
        int rowCnt = 0;

        while (iterator.hasNext()) {
            Row nextRow = iterator.next();

            Iterator<Cell> cellIterator = nextRow.cellIterator();
            List<String> obj = new ArrayList<String>();
            while (cellIterator.hasNext()) {
                Cell cell = cellIterator.next();

                String cellobj = cell.getStringCellValue();

                if ("".equals(cell.getStringCellValue())) {
                    obj.add("Missing");

                } else if (cellobj.equals(null)) {
                    obj.add("");

                } else {
                    obj.add(cell.getStringCellValue());
                }

            }

            data.put(rowCnt, obj);
            rowCnt++;

        }
        return data;
    }

}