public static void main(String[] args) {
        ThreadLocal threadLocal = new ThreadLocal();
        for(int i=0;i<3;i++){
            new Thread(()->{
                double random = Math.floor(Math.random()*10);
                threadLocal.set(random);
                System.out.println("設(shè)置線程"+Thread.currentThread().getName()+",線程變量："+random);
                System.out.println("查看線程"+Thread.currentThread().getName()+",線程變量："+threadLocal.get());
            }).start();
        }
    }

 public class Thread implements Runnable {
    ThreadLocal.ThreadLocalMap threadLocals = null;
 ｝

public void set(T value) {
		//獲取調(diào)用者線程
        Thread t = Thread.currentThread();
        //獲取調(diào)用者線程自有的ThreadLocalMap
        ThreadLocalMap map = getMap(t);
        if (map != null)
        	//如果map！=null直接設(shè)置值
            map.set(this, value);
        else
        	//創(chuàng)建ThreadLocalMap，并將value存儲(chǔ)
            createMap(t, value);
    }
    ThreadLocalMap getMap(Thread t) {
    	//獲取線程的ThreadLocalMap
        return t.threadLocals;
    }
    void createMap(Thread t, T firstValue) {
    	//創(chuàng)建ThreadLocalMap，并設(shè)置firstValue
        t.threadLocals = new ThreadLocalMap(this, firstValue);
    }

public T get() {
		//獲取調(diào)用者線程
        Thread t = Thread.currentThread();
        //獲取調(diào)用者線程自有的ThreadLocalMap
        ThreadLocalMap map = getMap(t);
        if (map != null) {
        	//獲取到當(dāng)前ThreadLocal的值
            ThreadLocalMap.Entry e = map.getEntry(this);
            if (e != null) {
                @SuppressWarnings("unchecked")
                T result = (T)e.value;
                return result;
            }
        }
        return setInitialValue();
    }
    private T setInitialValue() {
    	//獲取默認(rèn)值（null），也可以重寫(xiě)該方法
        T value = initialValue();
        //獲取調(diào)用者線程
        Thread t = Thread.currentThread();
        //獲取調(diào)用者線程自有的ThreadLocalMap
        ThreadLocalMap map = getMap(t);
        if (map != null)
        	//設(shè)置為空
            map.set(this, value);
        else
        	//創(chuàng)建一個(gè)ThreadLocalMap,賦值為空
            createMap(t, value);
        return value;
    }

public void remove() {
	     //獲取調(diào)用者線程自有的ThreadLocalMap
         ThreadLocalMap m = getMap(Thread.currentThread());
         if (m != null)
             //刪除ThreadLocalMap中key為當(dāng)前ThreadLocal的數(shù)據(jù)
             m.remove(this);
    }