[
https://issues.apache.org/jira/browse/COLLECTIONS-266?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12528688
]
Joerg Schaible commented on COLLECTIONS-266:
--------------------------------------------
1/ You cannot fix natural hash codes in general. It works for Enums since they
use always the same instance in the same VM.
2/ I've added a test case that does something similar ... I missed Julian's TC,
but yes, that test would be sufficient also
3/ I had complaints against adding the "transient". I can run the
TestAllPackages suite though and I assume (although I did not find where) that
it also contains compatibility tests for serialization, since there are such
objects in the data/test directory. This would prove Stephen's comment right
that Java serialization can deal with the situation - at least in one
direction. But I doubt it will work in the other direction i.e. an old version
of CC can read such a serialized object. Therefore I'd simply remove the final.
And IMHO it matters if the serialVersionUID changes, since the current code is
only broken for a special use case ;-)
> Issue with MultiKey when serialized/deserialized via RMI
> --------------------------------------------------------
>
> Key: COLLECTIONS-266
> URL: https://issues.apache.org/jira/browse/COLLECTIONS-266
> Project: Commons Collections
> Issue Type: Bug
> Components: KeyValue
> Affects Versions: 3.2
> Reporter: Julien Buret
> Priority: Minor
> Fix For: 3.3
>
> Attachments: COLLECTIONS-266.patch, collections-testcase-266.diff,
> MultiKey.java, TestCollections266.java, TestCollections266.java,
> TestCollections266.java
>
>
> This is because the hash code of MultiKey is calculated only once.
> So if the MultiKey is deserialized in an other jvm, and if one at least of
> the subkeys defines its hash code with System.identityHashCode() (for example
> all the enums does), then the hash code of the MultiKey is no longer valid,
> and you can't retreive the key in your Map.
> I fixed it by making the cached hash code field transient, and by
> recalculating the hash code during deserialization.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
