Reference

extends Object

java.lang.Object
↳	java.lang.ref.Reference

Known Direct Subclasses

WeakReference

Class Overview

Abstract base class for reference objects. This class defines the operations common to all reference objects. Because reference objects are implemented in close cooperation with the garbage collector, this class may not be subclassed directly.

Summary

Public Methods
void	clear() Clears this reference object.
Object	get() Returns this reference object's referent.

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Inherited Methods

From class java.lang.Object

boolean	equals(Object obj) Indicates whether some other object is "equal to" this one.
final Class<?>	getClass() Returns the runtime class of an object.
int	hashCode() Returns a hash code value for the object.
final void	notify() Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll() Wakes up all threads that are waiting on this object's monitor.
String	toString() Returns a string representation of the object.
final void	wait(long timeout, int nanos) Causes current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.
final void	wait(long timeout) Causes current thread to wait until either another thread invokes the `notify()` method or the `notifyAll()` method for this object, or a specified amount of time has elapsed.
final void	wait() Causes current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object.

Public Methods

public void clear ()

Clears this reference object. Invoking this method will not cause this object to be enqueued.

This method is invoked only by Java code; when the garbage collector clears references it does so directly, without invoking this method.

public Object get ()

Returns this reference object's referent. If this reference object has been cleared, either by the program or by the garbage collector, then this method returns null.

Returns

The object to which this reference refers, or null if this reference object has been cleared