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https://issues.apache.org/jira/browse/DBCP-358?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13890611#comment-13890611
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Mark Thomas commented on DBCP-358:
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I have a great deal of sympathy with the point that Balazs makes above. I
intend to explore removing the custom equals and hashcode methods entirely. I
know that this is going to break a bunch of tests. What I need to look at is
whether the tests are just testing for the current behaviour or whether - like
TransactionRegistry - the implementation actually depends on the current
behaviour. Assuming it is the former, I'll change the tests. If it is the
latter, I'll have to see what options I'm left with.
Regarding the TransactionRegistry, there is going to have to be a hack of some
form somewhere. My preferred approach at the moment is to make
getInnermostDelegateInternal() public but make it clear in the Javadoc that it
is not part of the API. What I like about this is that it becomes very clear
that the code that depends on the innermost delegate rather than having a
dependency on an equals implementation several hops away. This should also
provide a route to change any other code that depends on the current equals and
hashcode behaviour.
> Equals implementations in DelegatingXxx classes are not symmetric
> -----------------------------------------------------------------
>
> Key: DBCP-358
> URL: https://issues.apache.org/jira/browse/DBCP-358
> Project: Commons Dbcp
> Issue Type: Bug
> Affects Versions: 1.2, 1.2.2, 1.3, 1.4
> Reporter: Phil Steitz
> Fix For: 1.3.1, 1.4.1
>
>
> For reasons unclear to me, DelegatingConnection, DelegatingStatement,
> PoolGuardConnectionWrappers and other DBCP classes implement equals so that
> the wrapping class is considered equal to its innermost delegate JDBC object.
> This makes equals asymmetric when applied to a wrapper and its wrapped JDBC
> object - wrapper.equals(delegate) returns true, but delegate.equals(wrapper)
> will in general return false.
> I am pretty sure that DBCP itself does not rely on this bugged behavior, so I
> am inclined to fix it, making equals an equivalence relation on wrapper
> instances, with two considered equal iff their innermost delegates are equal.
> I can't imagine use cases where the bugged behavior is required. Can anyone
> else?
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