MyWriter of Numbers

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;

public class MyWriter {
    public static void main(String[] args) {
        System.out.println("Starting...");
        String fileName = "numbers.txt";
        try (PrintWriter writer = new PrintWriter(new File(fileName))) {
            int sep = 1;
            for (int i = 0; i < 10; i++) {
                sep++;
                writer.print(i);
                if (sep == 3) {
                    writer.write("\n");
                    sep = 1;
                }
            }
        } catch (final IOException ex) {
            ex.printStackTrace();
        }
    }
}