A HashMap bug with a Proxy value?

[Jing LV]

Hello, is there any other comments on this issue? Can someone help raise 
a bug on Sun's bug system? Thanks.


? 2011-1-19 17:06, Jing LV ??:
> Hi,
>
>        Thanks for information. I've raised a new bug on openjdk bug 
> system (https://bugs.openjdk.java.net/show_bug.cgi?id=100165) with 
> testcase and patch.
>
> ? 2011-1-14 1:46, Jason Mehrens ??:
>>
>> > I wonder the design for Proxy and InvocationHandler can be
>> > enhanced by creating a default equals/toString/hashCode implementation
>> > for Proxy correctly, not ask developers to do it again and again
>> > whenever he uses Proxy. Anyway, this may be another story.
>>
>> See: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4652876
>>
>> The ProxyGenerator could safely add byte codes to 
>> equals/compareTo/compare that:
>> 1. Handle the null case per contract: false, NPE, call handler.
>> 2. Proxy == Argument: true, 0, 0
>> 3. Proxy.getClass() == Argument.getClass() && Proxy.h == 
>> Proxy.getClass().cast(argument).h: true,0,0
>>
>> The problem is short circuit operations nor return value overrides 
>> are not allowed per the Proxy contract: "A method invocation on a 
>> proxy instance through one of its proxy interfaces will be dispatched 
>> to the invoke method of the instance's invocation handler...the 
>> result that it returns will be returned as the result of the method 
>> invocation on the proxy instance."
>>
>> I think for most equality checks, short circuit would be for the 
>> most part safe since most Collections all ready do such checks but, 
>> it requires a change to the Proxy contract which presents 
>> a compatibility problem.
>>
>>
>> > I think for HashMap, it may be benefit to check "==" as well as equals
>> > in containsValue() (as containsKey already do) which is a quick 
>> solution
>> > to resolve such problems.
>>
>> Seems like the identity check would be a win: 
>> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6486197
>>
>> Jason
>>
>>
>


-- 
Best Regards,
Jimmy, Jing LV

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/core-libs-dev/attachments/20110217/8a35b6d7/attachment.html>