Write CSV to String using opencsv without creating an actual file or a temp file

Question

I'm trying to use the opencsv library to write a csv file. The restriction being that I do not want to create a file on the disk or even a temp file. Is there a way I can achieve it?

From what I looked, the constructor for CSVWriter requires a FileWriter object.

Thanks!

Answer 1

Actually the constructor needs a Writer and you could provide a StringWriter to create a String.

Answer 2

To modify the example given here, just use a StringWriter instead of a FileWriter:

public static void main(String[] args) throws IOException {
    String[] rowData = {"column1", "column2", "column3"};

    try (StringWriter sw = new StringWriter(); CSVWriter csvWriter = new CSVWriter(sw)) {
        csvWriter.writeNext(rowData);

        String csv = sw.toString();
        System.out.println("CSV result: \n" + csv);
    }
}

Answer 3

Actually, CSVWriter takes a Writer instance, so you can simply pass a StringWriter. After the write operation, you can ask the StringWriter for it's content using toString().