LeetCode 59 - 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 int[][] generateMatrix(int n) {
    int[][] matrix = new int[n][n];
    int m = n, k = 0, l = 0;
    int v = 1;
    while(k<m && l<n) {
        for(int i=l; i<n; i++) {
            matrix[k][i] = v++;
        }
        k++;
        n--;
        for(int i=k; i<m; i++) {
            matrix[i][n] = v++;
        }
        if(l<n) {
            m--;
            for(int i=n-1; i>=l; i--) {
                matrix[m][i] = v++;
            }
        }
        if(k<m) {
            for(int i=m-1; i>=k; i--) {
                matrix[i][l] = v++;
            }
            l++;
        }
    }
    return matrix;
}