How to deal with CSV files having an unknown number of columns using Super CSV

Question

For a project I need to deal with CSV files where I do not know the columns before runtime. The CSV files are perfectly valid, I only need to perform a simple task on several different files over and over again. I do need to analyse the values of the columns, which is why I would need to use a library for working with CSV files. For simplicity, lets assume that I need to do something simple like appending a date column to all files, regardless how many columns they have. I want to do that with Super CSV, because I use the library for other tasks as well.

What I am struggeling with is more a conceptual issue. I am not sure how to deal with the files if I do not know in advance how many columns there are. I am not sure how I should define POJOs that map arbitrary CSV files or how I should define the Cell Processors if I do not know which and how many columns will be in the file. How can I dynamically create Cell processors that match the number of columns? How would I define POJOs for instance based on the header of the CSV file?

Consider the case where I have two CSV files: products.csv and address.csv. Lets assume I want to append a date column with today’s date for both files, without having to write two different methods (e.g. addDateColumnToProduct() and addDateColumnToAddress()) which do the same thing.

product.csv:

name, description, price
"Apple", "red apple from Italy","2.5€" 
"Orange", "orange from Spain","3€"

address.csv:

firstname, lastname
"John", "Doe"
"Coole", "Piet"

Based on the header information of the CSV files, how could I define a POJO that maps the product CSV? The same question for Cell Processors? How could I define even a very simple cell processor that just basically has the right amount of parameters for the constructor, e.g. for the product.csv

CellProcessor[] processor = new CellProcessor[] { 
    null,
    null,
    null
};

and for the address.csv:

CellProcessor[] processor = new CellProcessor[] { 
    null,
    null
};

Is this even possible? Am I on the wrong track to achieve this?

Edit 1: I am not looking for a solution that can deal with CSV files having variable columns in one file. I try to figure out if it is possible dealing with arbitrary CSV files during runtime, i.e. can I create POJOs based only on the header information which is contained in the CSV file during runtime. Without knowing in advance how many columns a csv file will have.

Solution Based on the answer and comments from @baba

private static void readWithCsvListReader() throws Exception {

        ICsvListReader listReader = null;
        try {
                listReader = new CsvListReader(new FileReader(fileName), CsvPreference.TAB_PREFERENCE);

                listReader.getHeader(true); // skip the header (can't be used with CsvListReader)
                int amountOfColumns=listReader.length();
                CellProcessor[] processor = new CellProcessor[amountOfColumns];
                List<Object> customerList;

                while( (customerList = listReader.read(processor)) != null ) {
                        System.out.println(String.format("lineNo=%s, rowNo=%s, customerList=%s", listReader.getLineNumber(),
                                listReader.getRowNumber(), customerList));
                }

        }
        finally {
                if( listReader != null ) {
                        listReader.close();
                }
        }
}

Answer 1

Maybe a little bit late but could be helpful...

  CellProcessor[] processors=new CellProcessor[properties.size()];

  for(int i=0; i< properties.zise(); i++){
            processors[i]=new Optional();

   }
    return  processors;