java.lang.ThreadLocalJava

文章发布较早，内容可能过时，阅读注意甄别。

# 1. 成员变量

AtomicInteger nextHashCode获得下个hashcode

# 2. 成员函数

get()从ThreadLocalMap中取元素ThreadLocalMap.Entry,ThreadLocalMap没有元素时，设置初始化值

    private T setInitialValue() {
        T value = initialValue();
        Thread t = Thread.currentThread();
        ThreadLocalMap map = getMap(t);
        if (map != null)
            map.set(this, value);
        else
            createMap(t, value);
        return value;
    }

1
2
3
4
5
6
7
8
9
10

remove()从ThreadLocalMap中remove(this)

# 3. 内部类

static final class SuppliedThreadLocal<T> extends ThreadLocal<T>在ThreadLocal默认初始化时使用

    public static <S> ThreadLocal<S> withInitial(Supplier<? extends S> supplier) {
        return new SuppliedThreadLocal<>(supplier);
    }

1
2
3
4

static class ThreadLocalMap类用于存储数据，此类中还有静态类

    static class Entry extends WeakReference<ThreadLocal<?>> {
        /** The value associated with this ThreadLocal. */
        Object value;

        Entry(ThreadLocal<?> k, Object v) {
            super(k);
            value = v;
        }
    }

1
2
3
4
5
6
7
8
9
10

#Java