java.lang.ref
Class Reference<T>

java.lang.Object
  java.lang.ref.Reference<T>

Direct Known Subclasses:

PhantomReference, SoftReference, WeakReference

public abstract class Reference<T>
extends Object

Reference is the common abstract super class for reference types WeakReference, SoftReference and PhantomReference.

This class may not be extended by user defined classes.

Since:

1.2

Method Summary

void	clear() Clear this reference, i.e., ensure that get() returns null.
boolean	enqueue() Enqueues this Reference on its associated ReferenceQueue.
protected void	finalize() finalize method.
T	get() Return the value of this reference if it is still alive, or null if it was deleted.
boolean	isEnqueued() Test if this reference has been enqueued to its reference queue.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

get

public T get()

Return the value of this reference if it is still alive, or null if it was deleted.

Returns:

the value of this reference or null.

clear

public void clear()

Clear this reference, i.e., ensure that get() returns null.

This method does not enqueue this reference.

isEnqueued

public boolean isEnqueued()

Test if this reference has been enqueued to its reference queue.

Returns:

true if this reference has an attached ReferenceQueue and it was enqueued.

enqueue

public boolean enqueue()

Enqueues this Reference on its associated ReferenceQueue.

For JamaicaVM, this method synchronized on the reference queue attached to this object for atomicity.

Returns:

false if no ReferenceQueue is associated or this Refernce was already enqueued.

finalize

protected void finalize()
                 throws Throwable

finalize method.

Overrides:

finalize in class Object

Throws:

Throwable - this method may throw any exception, it will be ignored by the finalizer thread or by Runtime.runFinalization.