All right, thanks~ 2012/9/17 feng lu <[email protected]>
> Hi > Maybe you can refer to > > http://hadoop.apache.org/docs/r1.0.3/api/org/apache/hadoop/mapred/lib/MultipleSequenceFileOutputFormat.html > > or > > > http://hadoop.apache.org/docs/r1.0.3/api/org/apache/hadoop/mapred/lib/MultipleTextOutputFormat.html > > example like this > > public static class GeneratorOutputFormat extends > MultipleSequenceFileOutputFormat<IntWritable,Text> { > // generate a filename based on the segnum stored for this text > protected String generateFileNameForKeyValue(IntWritable key, Text > value, > String name) { > return "ID_" + key.get() + ".dat"; > } > > } > > On Mon, Sep 17, 2012 at 3:16 PM, Jason Yang <[email protected]>wrote: > >> Hi, all >> >> I was wondering how to write all the input with the same key to a single >> file in the reducer ? >> >> say, I got some intermediate outputs from mappers like that: >> key value >> -------------------- >> 1 annie >> 2 Jason >> 1 andy >> 2 Joey >> 1 andrew >> ... >> >> and I would like write all the intermediate outputs with key 1 to file >> "ID_1.dat", and all the intermediate outputs with key 2 to file "ID_2.data". >> >> how could I achieve that? >> >> -- >> YANG, Lin >> >> > > > -- > Don't Grow Old, Grow Up... :-) > -- YANG, Lin
