Java for Leetcode 059 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]
]

Problem Solving Ideas:

Refer to Java for Leetcode 054 Spiral Matrix, modify the following code, Java implementation is as follows:

static public int[][] Generatematrix (int n) {        if (n==0)            return new int[0][0];    Int[][] Matrix=new int[n][n];    int num=0,left = 0, right = matrix[0].length-1, up = 0, down = matrix.length-1;        while (left <= right && up <= down) {for            (int i = left; I <= right&&up<=down; i++)                ma Trix[up][i]=++num;            up++;            for (int i = up; I <= down&&left<=right; i++)                matrix[i][right]=++num;            right--;            for (int i = right; I >= left&&up<=down; i--)                matrix[down][i]=++num;            down--;            for (int i = down; I >= up&&left<=right; i--)                matrix[i][left]=++num;            left++;        }    return matrix;      }

Java for Leetcode 059 Spiral Matrix II