How to write TestNG DataProvider annotation for Excel sheet with different column numbers for different rows

I have an Excel sheet with data as below

LoginPageValidation|            
LoginPage_login    | username1 | password1  
LoginPage_login    | username2 | password2   
LoginPage_login    | username3 | password3     

I am returning "array of arrays" to @Dataprovider form class reading ExcelSheet(Excelutility.java)

Is there any way to write @DataProvider which handles nullpointerException while reading data from rows with single column data.

public static Object[][] getTableArray() throws Exception 
{   
       String[][] tabArray = null;
       try {
           FileInputStream ExcelFile = new FileInputStream(FilePath);
           // Access the required test data sheet
           ExcelWBook = new XSSFWorkbook(ExcelFile);
           ExcelWSheet = ExcelWBook.getSheet(SheetName);
           int startRow = 0;
           int totalRows = ExcelWSheet.getLastRowNum()-ExcelWSheet.getFirstRowNum()+1;
           System.out.print("\nTOTAL ROWS "+totalRows+"\n");
    String a[][]=new String[totalRows][];
  for(int i=0;i<totalRows;i++)
  {
      int ColnumForRow=ExcelWSheet.getRow(i).getLastCellNum();
          a[i]=new String [ColnumForRow];
    for (int j=0;j<ExcelWSheet.getRow(i).getLastCellNum();j++)
    {
        if(getCellData(i,j).isEmpty())
        {System.out.println("\nEMPTY \n");}
        else
        { a[i][j]=getCellData(i,j);
          System.out.println("\nTABLE ARRAY : "+ a[i][j]);      
        }}
  }}
                return(tabArray);
        }

public static String getCellData(int RowNum, int ColNum) throws Exception 
    {try{   
             Cell = ExcelWSheet.getRow(RowNum).getCell(ColNum);
            int dataType = Cell.getCellType();
            String CellData = Cell.getStringCellValue();
                return CellData;
            }
        }

}

/testClass/
public class test1 { @Test(dataProvider="access") public void AADLoginLogoutTest(String test,String username,String pwd) throws IOException { System.out.println("CLAASS name AADLOGINLOGOUT"+this.getClass().getSimpleName()); } @DataProvider public Object[][] access() throws Exception { Object[][] testObjArray = ExcelUtils.getTableArray(); return (testObjArray); } }

refactored your code, try this, it must work..

  /**
     * @author revanthreddya
     *
     */
    package com.playground.excel;

    public class ExcelUtils 
    {
        private Workbook wb;
         private Sheet ws;

         public ExcelUtils(String file, String sheet) {
             try {

                   if (file.indexOf("xlsx") < 0) { 
                    wb = new HSSFWorkbook(new FileInputStream(new File(file)));
                    ws = wb.getSheet(sheet);
                   } else { 
                    wb = new XSSFWorkbook(new FileInputStream(new File(file)));
                    ws = (XSSFSheet) wb.getSheet(sheet);
                   }
                  } catch (IOException io) {
                   System.err.println("Invalid file '" + file
                     + "' or incorrect sheet '" + sheet
                     + "', enter a valid one");
                  }
        }


         public int rowCount(){
                return ws.getLastRowNum();
             }


         public String getCell(int rowIndex, int columnIndex) {
              Cell cell = null;

              try {
                cell = ws.getRow(rowIndex).getCell(columnIndex);
              } catch (Exception e) {
               System.err.println("The cell with row '" + rowIndex + "' and column '"
                 + columnIndex + "' doesn't exist in the sheet");
              }
              return new DataFormatter().formatCellValue(cell);
             }


    }



public class TestCase {

     @Test(dataProvider="access")
     public void AADLoginLogoutTest(String test, String username, String password) throws IOException 
     {
          System.out.println(" test :"+test+"  user "+username+"  password:"+  password); 
     }


     @DataProvider(name = "access")
     public Object[][] access() throws Exception {

      ExcelUtils userD= new ExcelUtils("input.xlsx", "Actions");

      ArrayList<Object> paraList = new ArrayList<Object>();

      int i = 1;
      int totalRows = userD.rowCount();
      System.out.println("TotalRows: "+totalRows);
      while (i < totalRows) {

       Object[] args = new Object[3];
       args[0] = userD.getCell(i, 0);
       args[1] = userD.getCell(i, 1);
       args[2] = userD.getCell(i, 2);

       paraList.add(args);

       i++;
      }

      Object[][] argsData = new Object[paraList.size()][];
      for (i = 0; i < paraList.size(); i++)
       argsData[i] = (Object[]) paraList.get(i);
      return argsData;
     }
}