Package java.lang.ref

 Abstract base class for reference objects. This class defines the operations common to all reference objects. Because reference objects are … API Doc
 Soft reference objects, which are cleared at the discretion of the garbage collector in response to memory demand. Soft references are most often… API Doc
 Phantom reference objects, which are enqueued after the collector determines that their referents may otherwise be reclaimed. Phantom references… API Doc
 Reference queues, to which registered reference objects are appended by the garbage collector after the appropriate reachability changes are… API Doc
 Weak reference objects, which do not prevent their referents from being made finalizable, finalized, and then reclaimed. Weak references are most … API Doc

Related Packages:

java.lang