Class WeakReference<T>

java.lang.Object
java.lang.ref.Reference<T>
java.lang.ref.WeakReference<T>
public non-sealed class WeakReference<T> extends Reference<T>
WeakReference objects are used to detect referents which are no longer visible.
Since:
1.2

  • Constructor Summary

    Constructors
    Constructor
    Description
    WeakReference(T r)
    Constructs a new instance of this class.
    WeakReference(T r, ReferenceQueue<? super T> q)
    Constructs a new instance of this class.

  • Method Summary

    Methods declared in class Reference

    clear, clone, enqueue, get, isEnqueued, reachabilityFence, refersTo
    Modifier and Type
    Method
    Description
    void
    clear()
    Make the referent null.
    protected Object
    clone()
    This method will always throw CloneNotSupportedException.
    boolean
    enqueue()
    Force the reference object to be enqueued if it has been associated with a queue.
    T
    get()
    Return the referent of the reference object.
    boolean
    isEnqueued()
    Deprecated.
    Use ReferenceQueue or Reference.refersTo(null).
    static void
    reachabilityFence(Object ref)
    Used to keep the referenced object strongly reachable so that it is not reclaimable by garbage collection.
    final boolean
    refersTo(T target)
    Does this object refer to target?

    Methods declared in class Object

    equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Constructor Details

    • WeakReference

      public WeakReference(T r, ReferenceQueue<? super T> q)
      Constructs a new instance of this class.
      Parameters:
      r - referent to track.
      q - queue to register to the reference object with.

    • WeakReference

      public WeakReference(T r)
      Constructs a new instance of this class.
      Parameters:
      r - referent to track.