## Uses of Class
java.lang.ref.Reference

Packages that use Reference
java.lang.ref: Provides reference-object classes, which support a limited degree of interaction with the garbage collector.

### Uses of Reference in java.lang.ref

Subclasses of Reference in java.lang.ref
`class` `PhantomReference<T>` Phantom reference objects, which are enqueued after the collector determines that their referents may otherwise be reclaimed.
`class` `SoftReference<T>` Soft reference objects, which are cleared at the discretion of the garbage collector in response to memory demand.
`class` `WeakReference<T>` Weak reference objects, which do not prevent their referents from being made finalizable, finalized, and then reclaimed.

Methods in java.lang.ref that return Reference
`Reference<? extends T>` ReferenceQueue.`poll()` Polls this queue to see if a reference object is available.
`Reference<? extends T>` ReferenceQueue.`remove()` Removes the next reference object in this queue, blocking until one becomes available.
`Reference<? extends T>` ReferenceQueue.`remove​(long timeout)` Removes the next reference object in this queue, blocking until either one becomes available or the given timeout period expires.