Life of the IT-Drummer

public class Node<E> {
	private E content;
	private Node<E> below;
 
	public Node(E content) { this.content = content; }
	public E getContent() { return content; }
	public void setContent(E content) { this.content = content;}
	public Node<E> getBelow() { return below; }
	public void setBelow(Node<E> below) { this.below = below;}
}

/**
 * Simple stack.
 * @author Tobias Rusås Olsen
 *
 * @param <E>
 */
public class SimpleStack<E> {
	private Node<E> topNode;
	private int size;
 
	/**
	 * Default constructor, sets the size of the stack to zero.
	 */
	public SimpleStack() { size = 0; }
 
	/**
	 * Push element to the stack
	 * @param content
	 * @return
	 */
	public boolean push(E content) {
		if(size!=0) {
			Node<E> newNode = new Node<E>(content);
			newNode.setBelow(topNode);
			topNode = newNode;
		}
		else topNode = new Node<E>(content);
		size++;
		return true;
	}
 
	/**
	 * Get element from the stack.
	 * @return
	 */
	public E pop() {
		if(size==0) return null;
		Node<E> returnNode = topNode;
		topNode = returnNode.getBelow();
		size--;
		return returnNode.getContent();
	}
 
	/**
	 * Look at top element of stack.
	 * @return
	 */
	public E peek() {
		if(size==0) return null;
		return topNode.getContent();
	}
 
	public int size() {
		return size;
	}
}