java源码解析

private static class Node {
E item;
Node next;
Node prev;

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

Node node(int index) {
// assert isElementIndex(index);

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

void linkBefore(E e, Node succ) {
// assert succ != null;
final Node pred = succ.prev;
final Node newNode = new Node<>(pred, e, succ);
succ.prev = newNode;
if (pred == null)
first = newNode;
else
pred.next = newNode;
size++;
modCount++;
}

public boolean remove(Object o) {
if (o == null) {
for (Node x = first; x != null; x = x.next) {
if (x.item == null) {
unlink(x);
return true;
}
}
} else {
for (Node x = first; x != null; x = x.next) {
if (o.equals(x.item)) {
unlink(x);
return true;
}
}
}
return false;
}