線程局部變量 threadLocal

//爲線程局部變量設置初始值
    static ThreadLocal<Object> threadLocal = new ThreadLocal<Object>() {
        @Override
        protected Object initialValue() {
            return "初始值";
        }
    };

    /**
     * 若是一個線程是從其餘某個線程中建立的，這個類將提供繼承的值
     */
    static ThreadLocal<Object> threadLocalII = new InheritableThreadLocal<Object>() {
        @Override
        protected Object childValue(Object o) {
            return "覆蓋繼承的值";
        }
    };

    public static void main(String args[]){
        threadLocalII.set(new Integer(123));

        Thread thread = new MyThread();
        thread.start();

        System.out.println("main = " + threadLocalII.get());
    }

    static class MyThread extends Thread{
        @Override
        public void run(){
            System.out.println("MyThread = " + threadLocalII.get());
        }
    }