Rotating matrix in java clockwise by 90 degree

public void rotateMatrixRight90Transpose(int[][] mat) {

    int m = mat.length;
    int n = mat[0].length;

    for (int i = 0; i < m; i++) {
      for (int j = i; j < n; j++) {
        int x = mat[i][j];
        mat[i][j] = mat[j][i];
        mat[j][i] = x;
        System.out.println("IC" + i + ":" + j);
      }
    }

    // swap cols
    for (int i = 0; i < m; i++) {
      for (int j = 0; j < n / 2; j++) {
        // swap mat[i][j] with mat[N-i-1][j]
        int temp = mat[i][j];
        mat[i][j] = mat[i][n - j - 1];
        mat[i][n - j - 1] = temp;
      }
    }
  }

public void rotate(int[][] matrix) {
    int n = matrix.length;
    for (int i = 0; i < (n + 1) / 2; i++) {
      for (int j = 0; j < n / 2; j++) {
        int temp = matrix[n - 1 - j][i];
        matrix[n - 1 - j][i] = matrix[n - 1 - i][n - j - 1];
        matrix[n - 1 - i][n - j - 1] = matrix[j][n - 1 - i];
        matrix[j][n - 1 - i] = matrix[i][j];
        matrix[i][j] = temp;
      }
    }
  }