线程的等待超时模式

    //对当前对象加锁
    public synchronized Object get(long mills) throws InterruptedException{
        long future = System.currentTimeMillis() + mills;
        long remaining = mills;
        //当超时大于0且result返回值不满足要求
        while ((result == null) && remaining > 0){
            wait(remaining);
            remaining = future - System.currentTimeMillis();
        }
        return result;
    }
}