Java 如何用二维数组创建空心菱形

package com.JavaBase; 
public class lingxing {
	// 菱形
 
	public static void main(String[] args) {
		int n = 15;//n只能是奇数
		int[][] a = new int[n][n];
		for (int i = 0; i < a.length; i++) {
			for (int j = 0; j < a[i].length; j++) {
				a[i][j] = 0;
				int p1 = a.length / 2 - i;
				int p2 = a[i].length / 2 + i;//p1,p2的规律非常好找
				if (i <= a.length / 2) {//上半部分
					a[i][p1] = 1;
					a[i][p2] = 1;
					if (a[i][j] == 1) {
						System.out.print("*");
					} else {
						System.out.print(" ");
					}
				} else {//下半部分
					int p3 = i - a.length / 2;//与p1相反
					int p4 = a.length - (i - a.length / 2) - 1;//p4的规律比较难找到
					a[i][p3] = 1;
					a[i][p4] = 1;
					if (a[i][j] == 1) {
						System.out.print("*");
					} else {
						System.out.print(" ");
					}
				}
			}
			System.out.println();
		}
	}
}

for(int i=0;i<array.length;i++)  
	     {  
	         for(int j=0;j<array[i].length;j++)  
	         {  
	             System.out.print(array[i][j]+" ");  
	         }  
	         System.out.println();  //换行  
	     }  

import java.util.Scanner; 
public class text_2 {
	public static void main(String[] args){
		System.out.println("请输入数组维度");
		Scanner sc = new Scanner(System.in);
		int num =sc.nextInt();
		text_2.printstart(num);			
	}
	public static void printstart(int n){
		int[][] array = new int[n][n];
		for (int row = 0;row<n/2;row++){
			for(int line = 0;line <(n/2-row);line++){
				array[row][line]=1;
				array[row][n-line-1]=1;
				array[n-row-1][line]=1;
				array[n-row-1][n-line-1]=1;
			}
		}
		for(int i=0;i<array.length;i++)  
	     {  
	         for(int j=0;j<array[i].length;j++)  
	         {  
	             System.out.print(array[i][j]+" ");  
	         }  
	         System.out.println();  //换行  
	     }  
		for(int row=0;row<n;row++){
			StringBuilder column = new StringBuilder();
			for(int line= 0;line<n;line++){
				if(array[row][line]==1){
					column.append("  ");
				}else{
					column.append("*");
				}
			}System.out.println(column);
		}
	}