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are these interface arguments ?

 
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Hello,
I'm a bit confused about what feature of Java this is. I am doing a bit of Hadoop and this syntax is something I've not seen before.



Can you tell me what <...> above is, and point me to an online page/tutorial regarding the same?

Thanks.

PS : Kindly note that I respect that this forum is only for Java related queries and not for Hadoop etc. Just thought I'd post it here, since it was a Java question.
 
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That's generics. It has nothing to do with interfaces, specifically.
 
Aftab Hassan
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Ulf Dittmer wrote:That's generics. It has nothing to do with interfaces, specifically.


Thanks a lot Ulf Dittmer for the pointer.
Googled and figured out the rest.

Marking the thread as solved.
 
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Who wrote a class with four type parameters?
 
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Campbell Ritchie wrote:Who wrote a class with four type parameters?


Don't know. But I think it is this class from hadoop: Mapper you can found this class' history here ;).
But if this is the class OP meant then this declaration:will result in a compile error.
You can't implement a class. Interface only.

Aftab, is full name of your Mapper class org.apache.hadoop.mapreduce.Mapper?
 
Aftab Hassan
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Pawel Pawlowicz wrote:Aftab, is full name of your Mapper class org.apache.hadoop.mapreduce.Mapper?


Yes, that's the one.
http://hadoop.apache.org/docs/r2.3.0/api/org/apache/hadoop/mapreduce/Mapper.html
 
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