SpringBootMultiLineString

@SpringBootApplication
public class Main implements CommandLineRunner {
 public static void main(String[] args) {
 SpringApplication.run(Main.class, args);
 System.out.println("I am in");
 }
 public void run(String... args) throws Exception {
 //Creating string reporte
 
 String reporte = "";
 for (int i = 0; i < 10; i++) {
 reporte = reporte +"Line"+i+ "\n";// Line1\nLine2\n.......
 }
 //Creating file.txt saving the string and defining as multiline
 
 FileWriter fileWriter = new FileWriter("file.txt", true);
 BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);
 bufferedWriter.write(reporte + "\n");
 bufferedWriter.flush();
 bufferedWriter.close();
 fileWriter.close();
 }
}