Concurrent container overview

ConcurrentHashMap; thread-safe HashMap
CopyOnWriteArrayList: thread-safe List
BlockingQueue: This is an interface that represents a blocking queue, which is very suitable as a data sharing channel.
ConcurrentLinkedQueue: An efficient non-blocking concurrent queue, implemented using a linked list. It can be regarded as a thread-safe LinkedList
ConcurrentSkipListMap: it is a Map that uses the data structure of a jump table for quick search.

History of collections

Vector和Hashtable

Using synchronized, the concurrency performance is poor.

ArrayList和HashMap

Although these two classes are not thread-safe, you can use Collections.synchronizedList(new ArrayListt) and Collections.synchronizedMap(new HashMap<K,V>()) to make them thread-safe.

ConcurrentHashMap

Introduction to Map
Why do you need ConcurrentHashMap
Analysis of HashMap
Implementation and analysis of ConcurrentHashMap of JDK1.7
ConcurrentHashMap implementation and source code analysis of JDK1.8
Regarding the advantages and disadvantages of JDK1.7 and JDK1.8, why change the structure of 1.7 to the structure of 1.8?
Combined operation: ConcurrentHashMap is also not thread-safe
Actual production case

Introduction to Map

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Common methods of Map interface


/**
 * @Classname MapDemo
 * @Description 演示Map的基本用法
 * @Date 2021/2/26 10:23
 * @Created by YoungLiu
 */
public class MapDemo {
    
    
    public static void main(String[] args) {
    
    
        Map<String,Integer> map = new HashMap<>();
        System.out.println(map.isEmpty());
        map.put("123",23);
        map.put("456",12);
        System.out.println(map.keySet());
        System.out.println(map.get("123"));
        System.out.println(map.size());
        System.out.println(map.containsKey("123"));
    }
}