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java.lang.ref

Class WeakReference

java.lang.Object
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+--java.lang.ref.Reference
   |
   +--java.lang.ref.WeakReference


public class WeakReference

extends Reference

A weak reference will be cleared, if the object is only weakly reachable. It is useful for lookup tables, where you aren't interested in an entry, if the key isn't reachable anymore. WeakHashtable is a complete implementation of such a table.
It is also useful to make objects unique: You create a set of weak references to those objects, and when you create a new object you look in this set, if the object already exists and return it. If an object is not referenced anymore, the reference will automatically cleared, and you may remove it from the set.

Author:See Also:

Constructor Summary

WeakReference(java.lang.Object referent)

Create a new weak reference, that is not registered to any queue.
WeakReference(java.lang.Object referent, java.lang.ref.ReferenceQueue q)

Create a new weak reference.

Constructor Details

WeakReference

public WeakReference(java.lang.Object referent)

Create a new weak reference, that is not registered to any queue.

Parameters:


WeakReference

public WeakReference(java.lang.Object referent, java.lang.ref.ReferenceQueue q)

Create a new weak reference.

Parameters:

Throws: