Convert binary tree to mirror tree in java

Java program for Convert binary tree to mirror tree. Here problem description and other solutions.

/* 
  Java program for
  Convert binary tree to it's mirror tree
*/
// Binary Tree Node
class TreeNode
{
    public int data;
    public TreeNode left;
    public TreeNode right;
    public TreeNode(int data)
    {
        // Set node value
        this.data = data;
        this.left = null;
        this.right = null;
    }
}
public class BinaryTree
{
    public TreeNode root;
    public BinaryTree()
    {
        // Set initial values
        this.root = null;
    }
    // Display inorder element
    public void inorder(TreeNode node)
    {
        if (node != null)
        {
            inorder(node.left);
            // Print node value
            System.out.print("  " + node.data);
            inorder(node.right);
        }
    }
    // Convert binary tree into mirror tree
    public void mirrorTree(TreeNode node)
    {
        if (node != null)
        {
            mirrorTree(node.left);
            mirrorTree(node.right);
            // Change left and right child 
            TreeNode temp = node.left;
            node.left = node.right;
            node.right = temp;
        }
    }
    public static void main(String[] args)
    {
        // Create new tree
        BinaryTree tree = new BinaryTree();
        /* Binary Tree
            -----------------------
                     1
                   /   \
                  6     8
                 / \   / \
                2   3 4   5
               /           \
              19            10
                        
            */
        // Add element
        tree.root = new TreeNode(1);
        tree.root.left = new TreeNode(6);
        tree.root.left.left = new TreeNode(2);
        tree.root.right = new TreeNode(8);
        tree.root.right.right = new TreeNode(5);
        tree.root.right.left = new TreeNode(4);
        tree.root.left.right = new TreeNode(3);
        tree.root.left.left.left = new TreeNode(19);
        tree.root.right.right.right = new TreeNode(10);
        System.out.print("\n Before convert");
        System.out.print("\n In-order Data : ");
        tree.inorder(tree.root);
        // Transform into mirror tree
        tree.mirrorTree(tree.root);
        /* 
            Mirror Tree
            --------------
                 1
               /   \
              8     6
             / \   / \
            5   4 3   2
           /           \
          10            19
                     
        */
        System.out.print("\n After convert");
        System.out.print("\n In-order Data : ");
        tree.inorder(tree.root);
    }
} 

Output

 Before convert
 In-order Data :   19  2  6  3  1  4  8  5  10
 After convert
 In-order Data :   10  5  8  4  1  3  6  2  19