Hey guys im working on a palindrome program that uses a stack and a queue

So far I have coded the Node class, the Stack class, and the Queue class.

I am not to sure that the Queue class is totally correct, but here are the classes, just looking to see if the classes are coded correctly, if everything is as it should be.

Code:
public class Node 
{
	private Object item;
	private Node next;
	
	public Node(Object newItem)
	{
		item = newItem;
		next = null;
	}
	
	public Node(Object newItem, Node nextNode)
	{
		item = newItem;
		next = nextNode;
	}
	
	public void setItem(Object newItem)
	{
		item = newItem;
	}
	
	public Object getItem()
	{
		return item;
	}
	
	public void setNext(Node nextNode)
	{
		next = nextNode;
	}
	
	public Node getNext()
	{
		return next;
	}
}
Code:
public class Stack
{
  private int top = 0;
  private int anArray[] ;
  final int MAX_SIZE = 20;
  
  public Stack()
  {
    anArray = new int[MAX_SIZE];
  }
  
  public boolean isEmpty()
  {
    if (top == 0)
      return true;
    else
      return false;      
  }
  
  public void createStack()
  {
    Stack newStack = new Stack();
  }

  public void push(int newItem)
  {
    newItem = anArray[top];
    top++;
  }
  
  public int pop()
  {
    top--;
    return anArray[top];
  }
  
  public void popAll()
  {
    anArray[top] = 0;
  }
  
  public int peek()
  {
    return anArray[top];
  }
  
  
}
Code:
public class Queue
{
 private Node lastNode;
 
 public Queue()
 {
	 lastNode = null;
 }
 
 public boolean isEmpty()
 {
	 return lastNode == null;
 }
 
 public void dequeueAll()
 {
	 lastNode = null;
 }
 
 public void enqueue(Object newItem)
 {
	 Node newNode = new Node(newItem);
	 
	 if (isEmpty())
	 {
		 newNode.setNext(newNode);
	 }
	 else
	 {
		newNode.setNext(lastNode.getNext());
	 	lastNode.setNext(newNode);
	 }
	 
	 lastNode = newNode;
 }
}
ANY COMMENTS, INPUT OR HELP IS APPRECIATED!!!!!!!!!!!!