A basic java implementation of Stack data structure. (Confused Coders)

Stack.java

class Item {
	intdata;
	Item next;

	public Item(int data) {
		this.data = data;
	}
}



public class Stack {

	private Item top;

	
 	public void push(int data) {
		if (null == top) {
			top = new Item(data);
		} else {
			Item item = new Item(data);
			item.next = top;
			top = item;
		}
	}
	

	public int pop() {
		int data = top.data;
		top = top.next;
		return data;
	}
	

	public void printStack() {
		Item tmp = top;

		if (top == null) {
			System.out.print("Stack is empty !!");
		}
		System.out.println();
		while (tmp != null) {
			System.out.print(" > " + tmp.data);
			tmp = tmp.next;
		}
	}
	

	public static void main(String[] args) {
		Stack stack = new Stack();
		stack.printStack();
		stack.push(5);
		stack.push(14);
		stack.push(3);
		stack.push(23);
		stack.printStack();
		System.out.print("\npoped: " + stack.pop());
		System.out.print("\npoped: " + stack.pop());
		stack.printStack();

	}

}