@Override public int run(String[] args) throws IOException { JobConf conf = JobBuilder.parseInputAndOutput(this, getConf(), args); if (conf == null) { return -1; } conf.setMapperClass(StationMapper.class); conf.setMapOutputKeyClass(Text.class); conf.setReducerClass(MultipleOutputsReducer.class); conf.setOutputKeyClass(NullWritable.class); conf.setOutputFormat(NullOutputFormat.class); // suppress empty part file MultipleOutputs.addMultiNamedOutput( conf, "station", TextOutputFormat.class, NullWritable.class, Text.class); JobClient.runJob(conf); return 0; }