# Uses of Class
java.lang.ref.Reference

Packages that use Reference
Package
Description
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
Modifier and Type
Class
Description
`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
Modifier and Type
Method
Description
`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.