A HashMap bug with a Proxy value? (original) (raw)

Chris Hegarty chris.hegarty at oracle.com
Wed Jan 12 16:43:02 UTC 2011

Are you referring to java.net.Proxy? Proxy.equals depends on the resolution of its address. Address resolution could change over time, depending on the caching policy. java.net.URL has a similar issue.

Strangely,I would have expected containsValue and containsKey to behave in a similar fashion. I think the specification for these methods is very clear, they should use equals(). I'm not sure if containsKey is correct if it accepts key equality.

-Chris

On 01/12/11 03:53 PM, Jing LV wrote:

Hello everyone,

(As I am new in OpenJDK, please tell me if I post on the wrong mailing-list). I find an odd behaviour of HashMap. If we put a value which is an instance of Proxy, it would return false while checking containsValue(proxyinstance). I checked use Proxy instance as a key, it works well. I suppose this is a bug of HashMap. By reading the code closely, I find the problem was that, for Proxy instance, Proxy.equals(Proxy) may return false (there are many discussions on this already). HashMap.containsKey() will check if there is a key in the map equals and/or the same with the given key(so it bypass equals check) with getEntry() method but HashMap.containsValue() does not. So a quick fix will be: check there is a value in the map that equals and/or the same with the given value. I'd like to report this bug to bugzilla of openjdk, with my testcase and patch. Please tell me if any comments. Thanks a lot. Best wishes! Jing LV

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