[jira] Commented: (HBASE-1593) TableMap's generic type inconsistcy with Hadoop

["Jonathan Gray (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HBASE-1593?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12725858#action_12725858 ] 

Jonathan Gray commented on HBASE-1593:
--------------------------------------

So can we close this issue?

> TableMap's generic type inconsistcy with Hadoop
> -----------------------------------------------
>
>                 Key: HBASE-1593
>                 URL: https://issues.apache.org/jira/browse/HBASE-1593
>             Project: Hadoop HBase
>          Issue Type: Bug
>          Components: mapred
>            Reporter: jaehong choi
>
> Hello~
> I've been trying to global sort rows whose key is LongWritable and value is Text type.
> Since there are a few result files after finishing a mapreduce job, I need to do a merge sort on them. 
> I want to sort rows in a decreasing order, but ImmutableBytesWritable only supports increasing sort.
> So, I assign LongWritable.DecreasingComparator on JobConf.setOutputKeyComparatorClass() in order that output keys are in decreasing order.
> However, There is a big problem. As you see, TableMap requires K must implement or extend WritableComparable<K>, but LongWritable only implements WritableComparable, not WritableComparable<LongWritable>. This makes a compilation time error.  
> I think we should come up with an idea to solve this one. 
> TableMap.java
> public interface TableMap<K extends WritableComparable<K>, V extends Writable>
> extends Mapper<ImmutableBytesWritable, Result, K, V> {
> }
> LongWritable.java
> public class LongWritable implements WritableComparable

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