Reading from a CSV file and writing to a new CSV file using openCSV in java

Question

I'm writing a program which reads a CSV file and I modify some columns.After modifying I have to write it to a new CSV file with modifications.

I have done till reading and modifying but when I'm writing it to a new file I'm just getting a single row.I'm struck here.

Help me overcome this?

I'm using openCSV and language is Java.

My code:

CSVReader reader;
try 
{   
  File file=new File("/home/srinivas/Desktop/saicharan/Cardsmod.csv");
  if(file.createNewFile()){ }
  reader = new CSVReader(new FileReader(filename));
  String filewrite="/home/srinivas/Desktop/saicharan/Cardsmod.csv";   
  CSVWriter writer=new CSVWriter(new FileWriter(filewrite));
  String[] row;
  while((row = reader.readNext()) != null)
  {
    String str=new String();
    String str1=new String();
    for(int i=0;i<row.length;i++)
    {
      str1=str1+","+row[i];
      if(row[i].equals("Card Text Listen"))
      {
        String [] nextLine = reader.readNext();
        String [] nextLine1=reader.readNext();
        str=str+nextLine[i]+nextLine1[i];           
        c2.met(str);
      }
      if(i==11)
      {
        String[] rowwrite=str1.split(",");
        writer.writeNext(rowwrite);                     
      }
    }
  }
  writer.close();
}

Thank You.

Answer 1

I saw you read and write to same file, so you should store all the row to a list and then init the writer after reader completed Exp:

String[] header;
        String[] row;
        int index = 0;
        // processing the header;
        header = reader.readNext();
        for (int i = 0; i < header.length; i++) {
            if (header[i].equals("Card Text Listen")) {
                index = i;
                break;
            }
        }
        // processing data
        while ((row = reader.readNext()) != null) {
            for (int i = 0; i < row.length; i++) {
                if (index == i) {
                    row[i] = "new value";
                    break;
                }
            }
            writer.writeNext(row);
        }