Name: jl125535 Date: 01/28/2003


FULL PRODUCT VERSION :
java version "1.4.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-b92)
Java HotSpot(TM) Client VM (build 1.4.0-b92, mixed mode)

FULL OPERATING SYSTEM VERSION :
Redhat 7.3
Linux D577A822.kabel.telenet.be 2.4.18-5 #1 Mon Jun 10
15:31:48 EDT 2002 i686 unknown
glibc-2.2.5-36


A DESCRIPTION OF THE PROBLEM :
The ability to use object identity for the keys in a
WeakHashMap can be useful for caches. I propose to have an
extra constructor for this case, with a boolean parameter to
indicate whether object identity or object equality should
be used. The default behaviour can then remain the same.

Example: I'm using a WeakHashMap to hold a cache of proxy
objects (entry= object->proxy) that are used to translate
types for method invocations between object created by two
different classloaders. I do this so that proxy objects are
reused (1 object, 1 proxy) and the object equality on
proxies remains valid (if proxy objects are not equal, the
underlying object are not either and vice versa). BUT, if I
don't use an adapted version of WeakHashMap, sometimes an
incorrect proxy object is returned. This happens when the
object has the same hash key and equals() returns true.


REPRODUCIBILITY :
This bug can be reproduced often.

CUSTOMER WORKAROUND :
One can create an adapted version of WeakHashMap. The key
differences are the eq method, and the usage of eq for keys
throughout the rest of the code (the only place where this
does not happen yet is in the equals method for entries).
(Review ID: 158622)
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