print all nodes in binary tree java

1public class Node<E>{
2	private Node left;
3  	private Node right;
4  	private E elem;
5  	public void printNodes(){
6    	if(left!=null){
7        	left.printNodes();
8        }
9      	System.out.println(elem);
10      	if(right!=null){
11        	right.printNodes();
12        }
13    }
14}