ReferenceQueue

public class ReferenceQueue extends Object

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

Public Constructor Summary

ReferenceQueue()
Constructs a new reference-object queue.

Public Method Summary

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

Inherited Method Summary

Public Constructors

public ReferenceQueue ()

Constructs a new reference-object queue.

Public Methods

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

public 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.

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

Parameters
timeout If positive, block for up to 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

public Reference<? extends T> remove ()

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