You are viewing a plain text version of this content. The canonical link for it is here.
Posted to common-dev@hadoop.apache.org by "Karthik Kambatla (JIRA)" <ji...@apache.org> on 2013/02/01 18:52:13 UTC
[jira] [Reopened] (HADOOP-9124) SortedMapWritable violates contract
of Map interface for equals() and hashCode()
[ https://issues.apache.org/jira/browse/HADOOP-9124?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Karthik Kambatla reopened HADOOP-9124:
--------------------------------------
Reopening for branch-1
> SortedMapWritable violates contract of Map interface for equals() and hashCode()
> --------------------------------------------------------------------------------
>
> Key: HADOOP-9124
> URL: https://issues.apache.org/jira/browse/HADOOP-9124
> Project: Hadoop Common
> Issue Type: Bug
> Components: io
> Affects Versions: 2.0.2-alpha
> Reporter: Patrick Hunt
> Assignee: Surenkumar Nihalani
> Priority: Minor
> Fix For: 2.0.3-alpha
>
> Attachments: hadoop-9124-branch1.patch, HADOOP-9124.patch, HADOOP-9124.patch, HADOOP-9124.patch, HADOOP-9124.patch, HADOOP-9124.patch, HADOOP-9124.patch, HADOOP-9124.patch, HADOOP-9124.patch, HADOOP-9124.patch, HADOOP-9124.patch
>
>
> This issue is similar to HADOOP-7153. It was found when using MRUnit - see MRUNIT-158, specifically https://issues.apache.org/jira/browse/MRUNIT-158?focusedCommentId=13501985&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13501985
> --
> o.a.h.io.SortedMapWritable implements the java.util.Map interface, however it does not define an implementation of the equals() or hashCode() methods; instead the default implementations in java.lang.Object are used.
> This violates the contract of the Map interface which defines different behaviour for equals() and hashCode() than Object does. More information here: http://download.oracle.com/javase/6/docs/api/java/util/Map.html#equals(java.lang.Object)
> The practical consequence is that SortedMapWritables containing equal entries cannot be compared properly. We were bitten by this when trying to write an MRUnit test for a Mapper that outputs MapWritables; the MRUnit driver cannot test the equality of the expected and actual MapWritable objects.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira