用java打印空心金字塔

import java.util.Scanner;
public class empty01 {
    public static void main(String[] args){
        Scanner myScanner = new Scanner(System.in);
        System.out.println("请输入金字塔所需行数");
        int line = myScanner.nextInt();
        for(int i = 1 ; i < line ; i++){
            for(int j = 1 ; j <= 2 * line - 1 ; j ++){
                if(j == line - i + 1 || j == line + i - 1){
                    System.out.print("*");
                } else {
                    System.out.print(" ");
                }
            }
            System.out.print("\n");
        }
        for(int j = 1 ; j <= 2 * line - 1 ; j ++){
            System.out.print("*");
        }
        myScanner.close();
    }
}