https://zhuanlan.zhihu.com/p/24687801?refer=dreawer
http://www.cnblogs.com/skywang12345/p/3323085.html
https://github.com/CarpenterLee/JCFInternals
http://www.cnblogs.com/whgk/category/909062.html
http://www.cnblogs.com/xiaoxi/category/929860.html
Collection
线程安全性
Vector、Stack：线程安全，ArrayList、LinkedList：非线程安全
实现方式
LinkedList：双向链表，ArrayList，Vector，Stack：数组
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ArrayList
LinkedList
Vector和Stack
CopyOnWriteArrayList
Map
HashMap
HashMap
LinkedMap
