用java语言打印一个空心菱形

以下是Java代码：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入菱形边长：");
        int n = sc.nextInt();

        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n - i; j++) {
                System.out.print(" ");
            }
            System.out.print("*");
            if (i > 1) {
                for (int k = 1; k <= 2 * i - 3; k++) {
                    System.out.print(" ");
                }
                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(" ");
            }
            System.out.print("*");
            if (i > 1) {
                for (int k = 1; k <= 2 * i - 3; k++) {
                    System.out.print(" ");
                }
                System.out.print("*");
            }
            System.out.println();
        }
    }
}

运行后输出对应边长为5的空心菱形：

请输入菱形边长：
5
    *
   * *
  *   *
 *     *
*       *
 *     *
  *   *
   * *
    *