手写自己的ThreadLocal（线程局部变量）

Posted 2020-10-22 java_pro

ThreadLocal对象通常用于防止对可变的单实例变量或全局变量进行共享。

package com.lxc.tet;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

public class MyThreadLocal<T> {
    private Map<Thread,T> map = new ConcurrentHashMap<Thread, T>();
    
    protected T initialValue(){
        return null;
    }
    
    public void set(T value){
        map.put(Thread.currentThread(), value);
    }
    
    public T get(){
        T result = null;
        result = map.get(Thread.currentThread());
        if(result==null && !map.containsKey(Thread.currentThread())){
            result=initialValue();
            set(result);
        }
        return result;
    }
    
    public void remove(){
        map.remove(Thread.currentThread());
    }
}