Binary Trees2-Mirror Binary Tree

For a given Binary Tree of type integer, update it with its corresponding mirror image.
Example:
Alt text

Input Format:
The first and the only line of input will contain the node data, all separated by a single space. Since -1 is used as an indication whether the left or right node data exist for root, it will not be a part of the node data.
Output Format:
The only line of output prints the mirrored tree in a level-wise order. 
Each level will be printed on a new line. Elements printed at each level will be separated by a single line.
Note:
You are not required to print anything explicitly. It has already been taken care of.
Constraints:
1 <= N <= 10^5
Where N is the total number of nodes in the binary tree.

Time Limit: 1 sec
Sample Input 1:
1 2 3 4 5 6 7 -1 -1 -1 -1 -1 -1 -1 -1
Sample Output 1:
1 
3 2 
7 6 5 4
Sample Input 2:
5 10 6 2 3 -1 -1 -1 -1 -1 9 -1 -1
Sample Output 2:
5 
6 10 
3 2 
9

****************************************Code**************************************

public static void mirrorBinaryTree(BinaryTreeNode<Integer> root){
		
		if(root==null)
			return;
		BinaryTreeNode<Integer> temp=root.left;
		root.left=root.right;
		root.right=temp;
		mirrorBinaryTree(root.left);
		mirrorBinaryTree(root.right);
	}