spiral matrix II

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.

For example,
Given n = 3,

You should return the following matrix:

[ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ]]

public class Solution {    public int[][] generateMatrix(int n) {        int x = 0;        int y = 0;        int num = 1;        int[][] result = new int[n][n];        while(n > 0)        {            if(n == 1)            {                result[y][x] = num++;                break;            }            for(int i = 0; i < n-1; i++)            {                result[y][x+i] = num++;            }            for(int i = 0; i < n-1; i++)            {                result[y+i][x+n-1] = num++;            }            for(int i = 0; i < n-1; i++)            {                result[y+n-1][x+n-1-i] = num++;            }            for(int i = 0; i < n - 1; i++)            {                result[y+n-1-i][x] = num++;            }            x++;            y++;            n = n-2;        }        return result;    }}