Bstiterator.java

    public Iterator<Integer> iterator() {
       return new BSTIterator();
    }

    /* Package Private Methods */

    Node findSuccessor(Node node) {
        if(node == null) {
            return null;
        }
        if (node.getRight() != null ) {
            Node pointer = node.getRight();
            return findMin(node);
        } else{
            Node dad = node.getDad();
            while(dad != null && node == dad.getRight()) {
               node = node.getDad();
               dad = dad.getDad();
            }
            return dad;
        }
    }
    Node findMin(Node node) {
        if (node == null)
            return null;
        if (node.getLeft() == null)
            return node;
        return findMin(node.getLeft());
    }

    class BSTIterator implements Iterator<Integer> {
        Node pointer = findMin(root);

        @Override
        public boolean hasNext() {
            return pointer != null;
        }


        @Override
        public Integer next() {
            if (pointer == null)
                throw new NoSuchElementException();
            int toReturn = pointer.getData();
            pointer = findSuccessor(pointer);
            return toReturn;
        }

        @Override
        public void remove() {
            throw new java.lang.UnsupportedOperationException("Not supported yet.");
        }
    }