EDIT

        logger.setLevel(Level.DEBUG);

        CSVReader csvReader = new CSVReader(reader, COMMA);

        // read header row and prepare the searchColumnMap

        String[] headerRow = csvReader.readNext();

        for(String colName : idSearchFields){

            int idx = ArrayUtils.indexOf(headerRow, colName);

            if(idx > -1){

        // read the rest of the file

        List<String[]> data = csvReader.readAll();

        csvReader = null; // release memory

        String matchIdCode;

        } // END of areas loop

        return resultMap;

    }