private void setHead(Node newHead) { if (newHead == null) { head = null; } else { Node oldHead = (Node) pj.find(head); pj.update(oldHead, newHead); } }
private Node getHead() { if (head == null) { return null; } else { return (Node) pj.find(head); } }
@Override public boolean isEmpty() { int size = pj.size(); if (size == 0) { return true; } else { return false; } }
@Override public boolean add(T e) { if (pj.contains(e)) { return false; } Node newNode = new Node(e); newNode.setItem(e); if (getHead() == null) { setHead(newNode); } else { Node last = getLastNode(); last.setNext(newNode); } return true; }
@Override public boolean contains(Object o) { return pj.contains(o); }