初学java，写个期末考试的题

package zuoye;
//输出一个棱形

public class Lx {


public static void main(String[] args) {
int n = 7;
for (int i = 1; i <= n; i++) {
for (int j = n - 1; j >= i; j--) {
System.out.print(" ");
}
for (int k = 1; k <= 2*i-1; k++) {
System.out.print("*");
}
System.out.println();
}
for (int i = n-1; i >=1; i--) {
for (int j = 1; j <= n-i; j++) {
System.out.print(" ");
}
for (int k = 1; k <= 2*i-1 ; k++) {
System.out.print("*");
}
System.out.println();
}
}
}