A Stack using LinkedList

LinkedListStack.java

import java.util.Iterator;
import java.util.NoSuchElementException;

public class LinkedListStack<Item> implements Iterable<Item> {
	private class Node {
		Item value;
		Node next;
	}

	private Node top;
	private int count;

	public LinkedListStack() {
		top = null;
		count = 0;
	}

	public boolean isEmpty() {
		if (top == null)
			return true;
		return false;
	}

	public void push(Item val) {
		Node n = new Node();
		n.value = val;
		n.next = top;
		top = n;
		count++;
	}

	public Item pop() throws Exception {
		if (top == null)
			throw new Exception("The stack is already empty");
		Item val = top.value;
		top = top.next;
		count--;
		return val;
	}

	public int size() {
		return count;
	}

	public Iterator<Item> iterator() {
		return new ListIterator();
	}

	private class ListIterator implements Iterator<Item> {
		private Node current = top;

		public boolean hasNext() {
			return top != null;
		}

		public void remove() {
			throw new UnsupportedOperationException();
		}

		public Item next() {
			if (!hasNext())
				throw new NoSuchElementException();
			Item item = current.value;
			current = current.next;
			return item;
		}
	}
}