java.lang.ref
Class ReferenceQueue<T>

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

public class ReferenceQueue<T>
extends Object   

Reference queues, to which registered reference objects are appended by the garbage collector after the appropriate reachability changes are detected.

Since:

1.2

Constructor Summary

ReferenceQueue ()
Constructs a new reference-object queue.

Method Summary

Reference <? extends T>	poll () Polls this queue to see if a reference object is available.
Reference <? extends T>	remove () Removes the next reference object in this queue, blocking until one becomes available.
Reference <? extends T>	remove (long timeout) Removes the next reference object in this queue, blocking until either one becomes available or the given timeout period expires.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReferenceQueue

public ReferenceQueue()

Constructs a new reference-object queue.

Method Detail

poll

public Reference   <? extends T> poll()

Polls this queue to see if a reference object is available. If one is available without further delay then it is removed from the queue and returned. Otherwise this method immediately returns null.

Returns:

A reference object, if one was immediately available, otherwise null

remove

public Reference   <? extends T> remove(long timeout)
                              throws IllegalArgumentException   ,
                                     InterruptedException   

Removes the next reference object in this queue, blocking until either one becomes available or the given timeout period expires.

This method does not offer real-time guarantees: It schedules the timeout as if by invoking the Object.wait(long) method.

Parameters:

timeout - If positive, block for up timeout milliseconds while waiting for a reference to be added to this queue. If zero, block indefinitely.

Returns:

A reference object, if one was available within the specified timeout period, otherwise null

Throws:

IllegalArgumentException - If the value of the timeout argument is negative

InterruptedException - If the timeout wait is interrupted

remove

public Reference   <? extends T> remove()
                              throws InterruptedException   

Removes the next reference object in this queue, blocking until one becomes available.

Returns:

A reference object, blocking until one becomes available

Throws:

InterruptedException - If the wait is interrupted