hadoop-common-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From David Rosenstrauch <dar...@darose.net>
Subject Re: Writable questions
Date Tue, 31 Aug 2010 17:07:15 GMT
On 08/31/2010 12:58 PM, Mark wrote:
> I have a question regarding outputting Writable objects. I thought all
> Writables know how to serialize themselves to output.
> For example I have an ArrayWritable of strings (or Texts) but when I
> output it to a file it shows up as
> 'org.apache.hadoop.io.ArrayWritable@21f7186f'
> Am I missing something? I would have expected it to output "String1
> String2 String3" etc. If I am going about this the wrong way can someone
> explain the proper way for my reduce phase to output a key and a list of
> values. Thanks

Writables know how to serialize and deserialize themselves (i.e., to a 
binary I/O stream).  But that doesn't necessarily mean that they have a 
toString method for generating human-readable output.


View raw message