LinkedList中addAll(int index, Collection<? extends E> c)函数分析
public boolean addAll(int index, Collection<? extends E> c) { if (index < 0 || index > size) throw new IndexOutOfBoundsException("Index: "+index+ ", Size: "+size); Object[] a = c.toArray(); int numNew = a.length; if (numNew==0) return false;modCount++; Entry<E> successor = (index==size ? header : entry(index)); Entry<E> predecessor = successor.previous;for (int i=0; i<numNew; i++) { Entry<E> e = new Entry<E>((E)a[i], successor, predecessor); predecessor.next = e; predecessor = e; } successor.previous = predecessor; size += numNew; return true; }