extends:http://www.cnblogs.com/dolphin0520/p/3933551.html
Iterator<Integer> iterator = list.iterator(); while(iterator.hasNext()){ Integer integer = iterator.next(); if(integer==2) iterator.remove(); }
ArrayList迭代修改抛出ConcurrentModificationException
原文：http://www.cnblogs.com/niray/p/5153551.html