集合类源码（一）概述

一个简单知识点，List和Set都是继承Collection接口，HashMap实现了Map接口，而这两个顶级接口的实现类都有哪些呢？

Collection

子接口：BlockingDeque, BlockingQueue, Deque, List, NavigableSet, Queue, Set, SortedSet, TransferQueue

BlockingDeque【双向阻塞队列】

实现类：LinkedBlockingDeque

BlockingQueue【阻塞队列】

实现类：ArrayBlockingQueue, DelayQueue, LinkedBlockingDeque, LinkedBlockingQueue, LinkedTransferQueue, PriorityBlockingQueue, SynchronousQueue

Deque【双向队列】

实现类：ArrayDeque, ConcurrentLinkedDeque, LinkedBlockingDeque, LinkedList

List【有序列表】

实现类：AbstractList, AbstractSequentialList, ArrayList, AttributeList, CopyOnWriteArrayList, LinkedList, RoleList, RoleUnresolvedList, Stack, Vector

NavigableSet【SortedSet的扩展】

实现类：ConcurrentSkipListSet, TreeSet

Queue【队列】

实现类：AbstractQueue, ArrayBlockingQueue, ArrayDeque, ConcurrentLinkedDeque, ConcurrentLinkedQueue, DelayQueue, LinkedBlockingDeque, LinkedBlockingQueue, LinkedList, LinkedTransferQueue, PriorityBlockingQueue, PriorityQueue, SynchronousQueue

Set【集合】

实现类：AbstractSet, ConcurrentHashMap.KeySetView, ConcurrentSkipListSet, CopyOnWriteArraySet, EnumSet, HashSet, JobStateReasons, LinkedHashSet, TreeSet

SortedSet【有序集合】

实现类：ConcurrentSkipListSet, TreeSet

TransferQueue【一个BlockingQueue，其中生产者可以等待消费者接收元素】

实现类：LinkedTransferQueue

结构图：

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Map

子接口：Bindings, ConcurrentMap, ConcurrentNavigableMap, NavigableMap, SortedMap
实现类：AbstractMap, Hashtable, LinkedHashMap

Bindings【一个key为string类型的key/value映射类型】

实现类：SimpleBindings

ConcurrentMap【线程安全Map】

实现类：ConcurrentHashMap, ConcurrentSkipListMap

ConcurrentNavigableMap【支持NavigableMap操作的ConcurrentMap】

实现类：ConcurrentSkipListMap

NavigableMap【SortedMap的扩展】

实现类：ConcurrentSkipListMap, TreeMap

SortedMap【有序Map】

实现类：ConcurrentSkipListMap, TreeMap

AbstractMap【抽象Map】

实现类：ConcurrentHashMap, ConcurrentSkipListMap, EnumMap, HashMap, IdentityHashMap, TreeMap, WeakHashMap

Hashtable【线程安全Map】

实现类：Properties, UIDefaults

接下来的文章会从功能、原理、优缺点三个方面来阐述上述所有实现类