In my program, I have to overwrite the current data to a CSV file. But after being overwritten, when I launch my program again, those data disappeared.

> public class writeFile {

    private Writer fw;
    public writeFile(String fileName) {
        try {
            fw = new FileWriter(fileName, false);
        } catch (IOException e) {
            System.out.println(e.toString());
        }
    }

    public void writeToCSV(String[] org) {
        String text = "";
        for(int i = 0; i < org.length; i++) {
            text += org[i];
            if(i != org.length - 1) {
                text += ",";
            } else {
                text += "n";
            }
        }
        try {
            fw.write(text);
            fw.flush();
            //fw.close();
        } catch (IOException e) {
            System.out.println(e.toString());
        }
    }

    public void shutDown() {
        try {
            fw.close();
        } catch(IOException e) {
            System.out.println(e.toString());
        }
    }
}

Above is my writeFile class. Can anyone help me to explain and fix it?