Name
Reference<T>
Synopsis
This
abstract class represents some type of indirect reference to a
referent.
get( )
returns the
referent if the reference has not been explicitly cleared by the
clear( )
method or
implicitly cleared by the garbage collector. There are three concrete
subclasses of Reference
. The garbage collector
handles these subclasses differently and clears their references
under different circumstances.
Each of the subclasses of
Reference
defines a constructor that allows a
ReferenceQueue
to be associated with the
Reference
object. The garbage collector places
Reference
objects onto their associated
ReferenceQueue
objects to provide notification
about the state of the referent object. isEnqueued(
)
tests whether a Reference
has been
placed on the associated queue, and enqueue( )
explicitly places it on the queue. enqueue( )
returns false
if the Reference
object does not have an associated ReferenceQueue
,
or if it has already been enqueued.
public abstract class Reference<T> { // No Constructor // Public Instance Methods public void clear( ); public boolean enqueue( ); public T get( ); public boolean isEnqueued( ); }
Subclasses
PhantomReference
,
SoftReference
, WeakReference
Returned By
ReferenceQueue.{poll( )
, remove(
)}
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