Read [Main implementation class of collection interface and map interface] Summary

Collection interface

List interface

LinkedList [asynchronous] linked list storage, introduction data slow insertion data Fast implementation synchronization: List List = Collections.synchronizedlist (new LinkedList (...));

ArrayList [asynchronous] similar to array storage, continuous storage, the introduction of data fast insertion of data slowly before inserting the Ensurecapacity method can be invoked to increase the ArrayList capacity to improve the insertion efficiency.

vector[Sync] similar to ArrayList

Stack inherits vector five unique methods: Push pop peak empty search

Set interface (object cannot be duplicated)

HashSet can quickly locate elements by hashcode find elements, ensuring a.equals (B) while A.hashcode () ==b.hashcode ()

TreeSet are stored sequentially and need to implement comparator interfaces

Map interface

TreeMap Keys Store Unique methods sequentially: Getfirstkey () Getlastkey ()

HashTable [Synchronous]key and value are NOT NULL to ensure a.equals (B) while A.hashcode () ==b.hashcode () by hashing function positioning

HashMap [async] allows NULL to create a synchronized map through Collections.synchronizedmap ()

Weakhashmap improved HashMap, weak references, when a key is no longer externally referenced will be collected by GC