数据结构---Java---LinkedList

public class LinkedList<E> extends AbstractSequentialList<E> implements List<E>, Deque<E>, Cloneable, java.io.Serializable
{

     +++++++++++内部类++++++++++++
     //双向链表
     private static class Node<E> {
        //结点元素值
        E item;
        //下一个结点索引
        Node<E> next;
        //上一个结点索引
        Node<E> prev;

        Node(Node<E> prev, E element, Node<E> next) {
            this.item = element;
            this.next = next;
            this.prev = prev;
        }
    }

     +++++++++++++属性+++++++++++++++++

      transient int size = 0;
      //头结点
      transient Node<E> first;
      //尾结点
      transient Node<E> last;

      +++++++++++++构造器++++++++++++++      

      public LinkedList() {
      }

      public LinkedList(Collection<? extends E> c) {
        this();
        addAll(c);
      }

      ++++++++++++方法++++++++++++++

      //+++++addFirst
      public void addFirst(E e) {
        linkFirst(e);
      }

      private void linkFirst(E e) {
        final Node<E> f = first;
        final Node<E> newNode = new Node<>(null, e, f);
        first = newNode;
        if (f == null)
            last = newNode;
        else
            f.prev = newNode;
        size++;
        modCount++;
      }

      //+++++++addLast
      public void addLast(E e) {
        linkLast(e);
      }

      void linkLast(E e) {
        final Node<E> l = last;
        final Node<E> newNode = new Node<>(l, e, null);
        last = newNode;
        if (l == null)
            first = newNode;
        else
            l.next = newNode;
        size++;
        modCount++;
       }

       //++++++add
       public boolean add(E e) {
        linkLast(e);
        return true;
       }

       //++++++++removeFirst
       public E removeFirst() {
        final Node<E> f = first;
        if (f == null)
            throw new NoSuchElementException();
        return unlinkFirst(f);
       }

       //++++++++++removeLast
       public E removeLast() {
        final Node<E> l = last;
        if (l == null)
            throw new NoSuchElementException();
        return unlinkLast(l);
       }

      //++++++++++++addAll
      public boolean addAll(Collection<? extends E> c) {
        return addAll(size, c);
      }

      ...

}