 Known Direct Subclasses
| PhantomReference<T> |
Implements a phantom reference, which is the weakest of the three types of
references. |
| SoftReference<T> |
A reference that is cleared when its referent is not strongly reachable and
there is memory pressure. |
| WeakReference<T> |
Implements a weak reference, which is the middle of the three types of
references. |
|
|
Known Indirect Subclasses
|
Class Overview
Provides an abstract class which describes behavior common to all reference
objects. It is not possible to create immediate subclasses of
Reference in addition to the ones provided by this package. It is
also not desirable to do so, since references require very close cooperation
with the system's garbage collector. The existing, specialized reference
classes should be used instead.
Summary
| Public Methods |
|---|
|
void
|
clear()
Makes the referent null.
|
|
boolean
|
enqueue()
Forces the reference object to be enqueued if it has been associated with
a queue.
|
|
T
|
get()
Returns the referent of the reference object.
|
|
boolean
|
isEnqueued()
Checks whether the reference object has been enqueued.
|
|
[Expand]
Inherited Methods |
|---|
From class
java.lang.Object
|
Object
|
clone()
Creates and returns a copy of this Object.
|
|
boolean
|
equals(Object o)
Compares this instance with the specified object and indicates if they
are equal.
|
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void
|
finalize()
Invoked when the garbage collector has detected that this instance is no longer reachable.
|
|
final
Class<?>
|
getClass()
Returns the unique instance of Class that represents this
object's class. |
|
int
|
hashCode()
Returns an integer hash code for this object.
|
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final
void
|
notify()
Causes a thread which is waiting on this object's monitor (by means of
calling one of the wait() methods) to be woken up.
|
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final
void
|
notifyAll()
Causes all threads which are waiting on this object's monitor (by means
of calling one of the wait() methods) to be woken up.
|
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String
|
toString()
Returns a string containing a concise, human-readable description of this
object.
|
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final
void
|
wait()
Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.
|
|
final
void
|
wait(long millis, int nanos)
Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the
specified timeout expires.
|
|
final
void
|
wait(long millis)
Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the
specified timeout expires.
|
|
Public Methods
public
void
clear
()
Makes the referent null. This does not force the reference
object to be enqueued.
public
boolean
enqueue
()
Forces the reference object to be enqueued if it has been associated with
a queue.
Returns
true if this call has caused the Reference to
become enqueued, or false otherwise
public
T
get
()
Returns the referent of the reference object.
Returns
- the referent to which reference refers, or
null if the
object has been cleared.
public
boolean
isEnqueued
()
Checks whether the reference object has been enqueued.
Returns
true if the Reference has been enqueued, false otherwise
