Check if given LinkedList is a pallindrome or not

My version of the program. Open to corrections and improvements

/*
	* To change this license header, choose License Headers in Project Properties.
	* To change this template file, choose Tools \| Templates
	* and open the template in the editor.
	*/
	package interview.practice;

	import data.structures.LinkedList.LinkedList;
	import data.structures.LinkedList.Node;
	import data.structures.Stack.Stack;

	/**
	*
	* @author jasleen
	*/
	public class isPallindrome {

	public static boolean isPallindrome(LinkedList list) {
	Node single = list.head(), doubl = list.head();
	Stack stack = new Stack();
	if (single == null\|\|single.next()==null) {
	return false;
	}
	while (single.next() != null && doubl.next().next() != null) {
	stack.push(single.key());
	single = single.next();
	doubl = doubl.next().next();
	if ( doubl.next() == null) {
	break;
	}
	}
	System.out.println(doubl);
	System.out.println(single);
	System.out.println(stack);
	if (doubl.next()!= null) {
	stack.push(single.key());
	single = single.next();

	Node popped=stack.extractTop();
	if (!single.key().toString().equals(popped.key().toString())) {
	System.out.println("Returning at key" + popped.key().toString()+single.key());
	return false;
	}

	}
	single = single.next();
	System.out.println(stack);
	//System.out.println(single.key());
	while (single != null) {
	Node popped=stack.extractTop();
	if (!single.key().toString().equals(popped.key().toString())) {
	System.out.println("Returning at key" + popped.key().toString()+single.key());
	return false;
	}
	single = single.next();
	}

	return true;
	}


	}