Handle Commas In CSV Columns - Apex(http://blog.lkatney.com/2017/09/13/handle-commas-in-csv-columns-apex/)

handleCommaInApex.cls

String csvLine = 'Test,Check,abc@abc.com, "19, Link road, A1SH10, India", companyName, "companyStreet, CompanyCity, CompanyCountry"';
String prevLine = csvLine;
Integer startIndex;
Integer endIndex;

while(csvLine.indexOf('"') > -1){

    if(startIndex == null){
        startIndex = csvLine.indexOf('"');
        csvLine = csvLine.substring(0, startIndex) + ':quotes:' + csvLine.substring(startIndex+1, csvLine.length());
    }else{
        if(endIndex == null){
            endIndex = csvLine.indexOf('"');
            csvLine = csvLine.substring(0, endIndex) + ':quotes:' + csvLine.substring(endIndex+1, csvLine.length());
        }
    }
    
    if(startIndex != null && endIndex != null){
        String sub = csvLine.substring(startIndex, endIndex);
        sub = sub.replaceAll(',', ':comma:');
        csvLine = csvLine.substring(0, startIndex) + sub + csvLine.substring(endIndex, csvLine.length());
        startIndex = null;
        endIndex = null;
    }
}

System.debug('prevLine:::'+prevLine);
System.debug('csvLine:::'+csvLine);

for(String column : csvLine.split(',')){
  column = column.replaceAll(':quotes:', '').replaceAll(':comma:', ',');
  System.debug('column::'+column);
}