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From rajesh putta <rajesh.p...@gmail.com>
Subject Re: Can I use MapWritable as a key?
Date Wed, 20 Jul 2011 05:24:30 GMT
Hi,
As per my knowledege is concerned
MapWritable doesn't implement Comparable, so I think it cannot be used as a
key. If u want that functionality, then u have to have a subclass that
implements Comparable and there u will define your key comparison logic.or
the other option would be to use SortedMapWritable as key.


Thanks& Regards
Rajesh Putta
M Tech CSE
IIIT-H

On Wed, Jul 20, 2011 at 5:32 AM, Choonho Son <choonho.son@gmail.com> wrote:

> I am newbie.
>
> Most of example shows that,
> job.setOutputKeyClass(Text.class);
>
> is it possible job.setOutputKeyClass(MapWritable.class);
>
> because my key is combination of values(src IP, src Port, dst Port,
> dst IP), so I want to use MapWritable as a key.
>
> example code is like:
>
> MapWritable mkey = new MapWritable();
> MapWritable mval = new MapWritable();
>
> mkey.put(new Text("sip"), new Text(array[3]));
> mkey.put(new Text("sport"), new Text(array[5]));
> mkey.put(new Text("proto"), new Text(array[7]));
> mkey.put(new Text("dport"), new Text(array[6]));
> mkey.put(new Text("dip"), new Text(array[4]));
>
>
> mval.put(new Text("bcount"), new IntWritable(bcount));
> mval.put(new Text("pcount"), new IntWritable(pcount));
>
> context.write(mkey, mval);
>

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