Java集合主要分为三个部分:
1.Collection:List集合,Set集合,Queue
2.Map键值对集合
3.工具类:Iterator迭代器,Enumeration枚举,Arrays数组工具和Collecitons工具
List:List,ArrayList,LinkedList,Vector
set:set,Hashset,Treeset,LinkedHashSet
https://blog.csdn.net/qq_33642117/article/details/52040345
Map:AbstractMap,SortedMap,NavigableMap,Dictionary,Enumeration
http://www.runoob.com/java/java-map-interface.html
泛型: