Depth or Height of a binary tree

height.java

import java.util.Stack;
import java.lang.*;

class Node {

    int data;
    Node left, right;

    public Node(int item) {
        data = item;
        left = right = null;
    }
}

class BinaryTree {

    Node root;

    public void printHeight() {
      System.out.println(" Height " + height(root));
    }
    
    public int height(Node root){
        
        if(root==null){
            return 0;
        }
        int left  = height(root.left);
        int right = height(root.right);
        return (Math.max(left, right) + 1);
    }
    
    public static void main(String args[]) {
        
        BinaryTree tree = new BinaryTree();
        tree.root = new Node(1);
        tree.root.left = new Node(2);
        tree.root.right = new Node(3);
        tree.root.left.left = new Node(4);
        tree.root.left.right = new Node(5);
        tree.printHeight();
    }
}