http://zh.visualgo.net/
Note: 数据集合存储结构，默认no synchronized，允许NULL，允许duplicate
Tree结构支持内部元素根据指定的规则排序
Collection
├List
│├LinkedList
│├ArrayList
│└Vector
│ └Stack
└Set
├HashSet
├TreeSet
Map
├Hashtable
├TreeMap
├HashMap
└WeakHashMap
Collection
List
- LinkedList
- 实现了List<E>, Deque<E>, Queue<E>
- List 【Every* element in the {@code List} has an index；allow duplicate* elements, as compared to Sets, where elements have to be unique】
- Deque 【double ended queue】【FIFO (First-In-First-Out) 】【Deques can also be used as LIFO (Last-In-First-Out) stacks】
注:push-pollLast 满足LIFO
add-poll满足FIFO
- you should probably use {@link ArrayList} if you don't need the queue-like behavior.
- ArrayList
ArrayList is an implementation of {@link List}, backed by an array.
- Vector
Vector is an implementation of {@link List}, backed by an array and synchronized.
- Stack
- {@code Stack} is a **Last-In/First-Out(LIFO) *data structure which represents a stack of objects.
- including null objects. There is no limit to the size of the stack.
Set
(A {@code Set} is a data structure which does not allow duplicate elements.)
- TreeSet
- 实现了SortedSet接口，支持元素排序
- HashSet
Map
A {@code Map} is a data structure consisting of a set of keys and values in which each key is mapped to a single value.
- HashTable
- Hashtable is a synchronized implementation of {@link Map}. All optional operations are supported.
- **Neither keys nor values can be null. *(Use {@code HashMap} or {@code LinkedHashMap} if you need null keys or values.)
- TreeMap
A map whose entries are sorted by their keys.
- HashMap
Note: the implementation of {@code HashMap} is not synchronized.
- WeakHashMap
WeakHashMap is an implementation of Map with keys which are WeakReferences.
- LinkedHashMap
doubly-linked list
