BST and Binary Tree Assignment::Pair sum in a BST

import java.util.ArrayList;

public class Solution {

/*	Binary Tree Node class
 * 
 * class BinaryTreeNode<T> {
		T data;
		BinaryTreeNode<T> left;
		BinaryTreeNode<T> right;
		
		public BinaryTreeNode(T data) {
			this.data = data;
		}
	}
	*/


// 	public static void printNodesSumToS(BinaryTreeNode<Integer> root, int s) {
//       printNodesSumToS(root ,root ,s);
        
//     }

//     public static void printNodesSumToS(BinaryTreeNode<Integer> temp1 ,BinaryTreeNode<Integer> temp2 ,int s){
//         if(temp1 == null){
//             return;
//         }
//         if(temp2 == null){
//             return;
//         }
        
//         printNodesSumToS(temp1.left, temp2 ,s);
//         printNodesSumToS(temp1, temp2.right ,s);

//         int sum = temp1.data + temp2.data;

//         if(sum == s){
//             System.out.println(temp1.data+" "+temp2.data);
//             printNodesSumToS(temp1.right ,temp2.left ,s);
//             //printNodesSumToS(temp2.left);
//         }else if(sum > s){
//             printNodesSumToS(temp1 ,temp2.left ,s);
//         }else{
//             printNodesSumToS(temp1.right ,temp2 ,s);
//         }
            

//     }
    
    
    public static void printNodesSumToS(BinaryTreeNode<Integer> root, int sum) {
		
        Queue<BinaryTreeNode<Integer>> pendingNodes = new Queue<>();
		ArrayList<Integer> list = new ArrayList<>();
		pendingNodes.enqueue(root);
		while (!pendingNodes.isEmpty()) {
			BinaryTreeNode<Integer> frontNode = null;
			int counter = pendingNodes.size();
			for (int i = 0; i < counter; i++) {
				try {
					frontNode = pendingNodes.dequeue();
				} catch (QueueEmptyException e) {
					e.printStackTrace();
				}
				list.add(frontNode.data);
				if (frontNode.left != null) {
					pendingNodes.enqueue(frontNode.left);
				}
				if (frontNode.right != null) {
					pendingNodes.enqueue(frontNode.right);
				}
			}
		}
		for (int i = 0; i < list.size(); i++) {
			for (int j = 0; j != i && j < list.size(); j++) {
				if (list.get(i) + list.get(j) == sum) {
					if (list.get(i) < list.get(j)) {
						System.out.println(list.get(i) + " " + list.get(j));
					} else {
						System.out.println(list.get(j) + " " + list.get(i));
					} 
				}
			}
		}

	}

}