一、属性及获取属性：

1、size

transient int size = 0;/** * Pointer to first node. * Invariant: (first == null && last == null) || *            (first.prev == null && first.item != null) */transient Node
    
      first;/** * Pointer to last node. * Invariant: (first == null && last == null) || *            (last.next == null && last.item != null) */transient Node
     
       last;
     
    

获取

public int size() {    return size;}

二、构造函数

//Constructs an empty listpublic LinkedList() {}public LinkedList(Collection
     c) {    this();    addAll(c);}

三、类

private static class Node
    
      {    E item;    Node
     
       next;    Node
      
        prev;    Node(Node
       
         prev, E element, Node
        
          next) {        this.item = element;        this.next = next;        this.prev = prev;    }}
        
       
      
     
    

四、方法

1、Node

Node
    
      node(int index) {    // assert isElementIndex(index);    if (index < (size >> 1)) {        Node
     
       x = first;        for (int i = 0; i < index; i++)            x = x.next;        return x;    } else {        Node
      
        x = last;        for (int i = size - 1; i > index; i--)            x = x.prev;        return x;    }}
      
     
    

*、linkFirst

/** * Links e as first element. */private void linkFirst(E e) {    final Node
    
      f = first;    final Node
     
       newNode = new Node<>(null, e, f);    first = newNode;    if (f == null)        last = newNode;    else        f.prev = newNode;    size++;    modCount++;}void linkLast(E e) {    final Node
      
        l = last;    final Node
       
         newNode = new Node<>(l, e, null);    last = newNode;    if (l == null)        first = newNode;    else        l.next = newNode;    size++;    modCount++;}
       
      
     
    

*、add、addFirst

public void addFirst(E e) {    linkFirst(e);}public boolean add(E e) {    linkLast(e);    return true;}

linkLast

2、set

public E set(int index, E element) {    checkElementIndex(index);    Node
    
      x = node(index);    E oldVal = x.item;    x.item = element;    return oldVal;}
    

3、get

public E get(int index) {    checkElementIndex(index);    return node(index).item;}

*、clear

public void clear() {    // Clearing all of the links between nodes is "unnecessary", but:    // - helps a generational GC if the discarded nodes inhabit    //   more than one generation    // - is sure to free memory even if there is a reachable Iterator    for (Node
    
      x = first; x != null; ) {        Node
     
       next = x.next;        x.item = null;        x.next = null;        x.prev = null;        x = next;    }    first = last = null;    size = 0;    modCount++;}
     
    

*、Push Pop

public void push(E e) {    addFirst(e);}

public E pop() {    return removeFirst();}

*、node(int index)

Node
    
      node(int index) {    // assert isElementIndex(index);    if (index < (size >> 1)) {        Node
     
       x = first;        for (int i = 0; i < index; i++)            x = x.next;        return x;    } else {        Node
      
        x = last;        for (int i = size - 1; i > index; i--)            x = x.prev;        return x;    }}