But this sounds like a runtime problem, not a type checking problem.
Polymorphism is generally a problem in the Hadoop API. That is why we
have VectorWritable and why I added PolymorphicWritable.
Jeff,
Two questions:
1) would PolymorphicWritable<Cluster> help?
2) can you say more about what the IOException is? Does it give any hints?
On Sun, Feb 12, 2012 at 7:00 AM, Paritosh Ranjan <pran...@xebia.com> wrote:
> Can something like this help?
>
> public class CIMapper<T extends Cluster> extends
> Mapper<WritableComparable<?>,**VectorWritable,IntWritable,T> {
> ...
> }
>
> On 12-02-2012 06:48, Jeff Eastman wrote:
>
>> I'm wondering how to tease the elephant into accepting any concrete
>> instance of the interface o.a.m.clustering.Cluster when writing trained
>> clusters in the cleanup() method of CIMapper. I've gotten the MR version of
>> the ClusterIterator to get to that point in testing but it blows chunks
>> with an IOException when I try to pass a o.a.m.clustering.kmeans.**Cluster
>> (I will rename the latter for 0.7). Seems the MapTask.collect() wants ==
>> and not instanceof.
>>
>> I've talked with Ted about passing Clusters rather than the current
>> ClusterObservations but don't see how at this point. Any ideas?
>>
>>
>>
>
