java 中modCount 详解及源码分析

java/83864.html">java;">private abstract class HashIterator<E> implements Iterator<E> {    Entry<K,V> next;    // next entry to return    int expectedModCount;  // For fast-fail    int index;       // current slot    Entry<K,V> current;   // current entry    HashIterator() {      expectedModCount = modCount;      if (size > 0) { // advance to first entry        Entry[] t = table;        while (index < t.length && (next = t[index++]) == null)          ;      }    }    public final boolean hasNext() {      return next != null;    }    final Entry<K,V> nextEntry() {      if (modCount != expectedModCount)        throw new ConcurrentModificationException();      Entry<K,V> e = next;      if (e == null)        throw new NoSuchElementException();      if ((next = e.next) == null) {        Entry[] t = table;        while (index < t.length && (next = t[index++]) == null)          ;      }      current = e;      return e;    }    public void remove() {      if (current == null)        throw new IllegalStateException();      if (modCount != expectedModCount)        throw new ConcurrentModificationException();      Object k = current.key;      current = null;      HashMap.this.removeEntryForKey(k);      expectedModCount = modCount;    }  }