findGivenNode(root, key, foundNode, parentStack);

private boolean findGivenNode(Node node, int key, Node foundNode, Stack<Node> parentStack) {
    if (node == null) {
        return false;
    }

    parentStack.add(node);
    if (node.getData() == key) {
        foundNode = node;
        return true;
    }
    boolean leftReturn = findGivenNode(node.getLeftChild(), key, foundNode, parentStack);
    boolean RightReturn = findGivenNode(node.getRightChild(), key, foundNode, parentStack);
    if (leftReturn || RightReturn) {
        return true;
    }  else {
        parentStack.pop();
        return false;
    }
}

foundNode = node; // this doesn't reflect outside of the method

foundNode.setData(node.getData()); // this will reflect outside of the method

findGivenNode(root, key, foundNode, parentStack);