```
public class Solution {
public void rotate(int[][] matrix) {
int tmp,
n = matrix.length;
for (int i = 0; i <= (n-1)/2; i++) {
for (int j = i; j < n-i-1; j++) {
int times = 4;
int tmpI = i;
int tmpJ = j;
tmp = matrix[i][j];
while (times-- > 0) {
int a = tmpJ;
int b = n - tmpI - 1;
int c = tmp;
tmp = matrix[a][b];
matrix[a][b] = c;
tmpI = a;
tmpJ = b;
}
}
}
}
}
```