Christmas tree

import java.util.Scanner;
class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter the number of stars: ");
    int n = Integer.parseInt(sc.nextLine());
    for(int i = 0;i<=n;i++){
      String stars = generateFrom("*",i);
      String spaces = generateFrom(" ",n-i);
      System.out.print(spaces);
      System.out.print(stars);
      System.out.print("|");
      System.out.print(stars);
      System.out.print(spaces);
      System.out.println();
    }

  }

  public static String generateFrom(String symbol, int numberOfStars){
    StringBuffer builder = new StringBuffer();
    for(int i = 0;i< numberOfStars;i++){
      builder.append(symbol);
    }
    return builder.toString();
  }
}