The Entry type, which is used to store the key-value mapping, extends WeakReference, so when expungeStaleEntries() asks for the next expired weak reference, it gets back an Entry.

It would be nice if there was a way to be notified when the referent of a weak reference is garbage collected, and that is what reference queues are for.

如果有一种方法可以在弱引用的referent被垃圾收集时发出通知就好了，这就是引用队列的作用。

If the weak reference has been cleared ( either because the referent has already been garbage collected or because someone called WeakReference. clear()), get() returns null.

如果弱引用被清除了（不管是referent已经被垃圾收集了，还是有人调用了WeakReference.clear（）），get（）会返回null。

Dead mappings could be eliminated by periodically scanning the Map, calling get() on each weak reference, and removing the mapping if get() returns null.

可以通过周期性地扫描Map，对每一个弱引用调用get（），并在get（）返回null时删除那个映射而消除死映射。

The weak reference from the long-lived object to the short-lived object is kept long after the short-lived object has been destroyed.

在短周期对象销毁后，长周期对象对短周期对象的弱引用依然会长久保留下来。

Using a weak reference here keeps objects that are above the minimum around as long as possible, but makes them available for GC as required.

在此使用弱引用可以使除最低数量对象以外的对象尽可能久地保持活跃状态，但是使它们可供GC根据需要使用。

If the minimum number of objects is already allocated, then a weak reference to the object is enqueued.

如果已经分配了最低数量的对象，则对象的弱引用被放置到队列中。

GC is a thread of very low priority, so a weak reference object may not be collected immediately.

因为垃圾回收器是一个优先级很低的线程，所以弱引用对象也不一定会马上就会被回收。

From above shall we say that an object can't have a soft reference and a weak reference at the same time?

从以上是否能看出，一个对象不能同时具有软引用和弱引用？

A weak reference is a holder for a reference to an object, called the referent.

弱引用是对一个对象（称为referent）的引用的持有者。

Garbage collector scans the long weak reference table.

垃圾收集器扫描长弱引用表。

A long weak reference is created.

则创建长弱引用。

We'd better hurry or we'll be in for it.

我们最好赶快，不然要受罚的。

We'd better take a taxi.

我们最好乘出租车。

We'd recommend you to book your flight early.

我们建议你早点儿预订航班。

We'd better hurry or we'll miss the train.

我们最好快点，否则就赶不上火车了。

We'd been to hell and back together and we were still good friends.

我们曾经患难与共，现在依然是好友。

Suddenly it clicked ─ we'd been talking about different people.

我们突然领悟到原来我们谈论的不是同一个人。

We'd better leave now or we'll miss the bus.

我们最好现在就走，不然就赶不上公共汽车了。

Bring the family round one evening; we'd love to meet them.

哪天晚上带全家人来坐坐，我们很想见见他们。

I think we'd better drop the subject.

我认为我们最好不要再谈这个话题。