java并发容器
ConcurrentHashMap
===============
CopyOnWriteArrayList
CopyOnWriteArraySet
适用于读多写少的场景
===============
ConcurrentLinkedQueue
原理可参考
http://www.cnblogs.com/studyLog-share/p/5283646.html
https://my.oschina.net/xianggao/blog/390390
http://ifeve.com/concurrentlinkedqueue/