How to get an Excel Blank Cell Value in Apache POI?

If you want to get all cells, no matter if they exist or not, then the iterator isn’t for you. Instead, you need to manually fetch the appropriate cells, likely with a missing cell policy

for(Row row : sheet) {
   for(int cn=0; cn<row.getLastCellNum(); cn++) {
       // If the cell is missing from the file, generate a blank one
       // (Works by specifying a MissingCellPolicy)
       Cell cell = row.getCell(cn, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
       // Print the cell for debugging
       System.out.println("CELL: " + cn + " --> " + cell.toString());
   }
}

There’s more details on all of this in the Apache POI documentation on iterating over cells