content: package hip.ch3.avro;
  
  import hip.ch3.avro.gen.Stock;
  import hip.ch3.avro.gen.StockAvg;
  import hip.util.Cli;
  import hip.util.CliCommonOpts;
  import org.apache.avro.mapred.AvroInputFormat;
  import org.apache.avro.mapred.AvroJob;
  import org.apache.avro.mapred.AvroOutputFormat;
  import org.apache.avro.mapred.AvroWrapper;
  import org.apache.commons.math.stat.descriptive.moment.Mean;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.conf.Configured;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.io.DoubleWritable;
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.io.compress.SnappyCodec;
  import org.apache.hadoop.mapred.*;
  import org.apache.hadoop.util.Tool;
  import org.apache.hadoop.util.ToolRunner;
  
  import java.io.IOException;
  import java.util.Iterator;
  
  public class AvroMixedMapReduce extends Configured implements Tool {
  
    /**
     * Main entry point for the example.
     *
     * @param args arguments
     * @throws Exception when something goes wrong
     */
    public static void main(final String[] args) throws Exception {
      int res = ToolRunner.run(new Configuration(), new AvroMixedMapReduce(), args);
      System.exit(res);
    }
  
    /**
     * The MapReduce driver - setup and launch the job.
     *
     * @param args the command-line arguments
     * @return the process exit code
     * @throws Exception if something goes wrong
     */
    public int run(final String[] args) throws Exception {
  
  
      Cli cli = Cli.builder().setArgs(args).addOptions(CliCommonOpts.MrIoOpts.values()).build();
      int result = cli.runCmd();
  
      if (result != 0) {
        return result;
      }
  
      Path inputPath = new Path(cli.getArgValueAsString(CliCommonOpts.MrIoOpts.INPUT));
      Path outputPath = new Path(cli.getArgValueAsString(CliCommonOpts.MrIoOpts.OUTPUT));
  
      Configuration conf = super.getConf();
  
      JobConf job = new JobConf(conf);
      job.setJarByClass(AvroMixedMapReduce.class);
  
      job.set(AvroJob.INPUT_SCHEMA, Stock.SCHEMA$.toString());
      job.set(AvroJob.OUTPUT_SCHEMA, StockAvg.SCHEMA$.toString());
      job.set(AvroJob.OUTPUT_CODEC, SnappyCodec.class.getName());
  
      job.setInputFormat(AvroInputFormat.class);
      job.setOutputFormat(AvroOutputFormat.class);
  
      job.setMapperClass(Map.class);
      job.setReducerClass(Reduce.class);
  
      job.setMapOutputKeyClass(Text.class);
      job.setMapOutputValueClass(DoubleWritable.class);
  
      job.setOutputKeyClass(Text.class);
      job.setOutputValueClass(DoubleWritable.class);
  
      FileInputFormat.setInputPaths(job, inputPath);
      FileOutputFormat.setOutputPath(job, outputPath);
  
      return JobClient.runJob(job).isSuccessful() ? 0 : 1;
    }
  
    public static class Map extends MapReduceBase
        implements
        Mapper<AvroWrapper<Stock>, NullWritable, Text, DoubleWritable> {
  
      public void map(AvroWrapper<Stock> key,
                      NullWritable value,
                      OutputCollector<Text, DoubleWritable> output,
                      Reporter reporter) throws IOException {
        output.collect(new Text(key.datum().getSymbol().toString()),
            new DoubleWritable(key.datum().getOpen()));
      }
    }
  
    public static class Reduce extends MapReduceBase
        implements Reducer<Text, DoubleWritable, AvroWrapper<StockAvg>,
        NullWritable> {
  
      public void reduce(Text key,
                         Iterator<DoubleWritable> values,
                         OutputCollector<AvroWrapper<StockAvg>,
                             NullWritable> output,
                         Reporter reporter) throws IOException {
  
        Mean mean = new Mean();
        while (values.hasNext()) {
          mean.increment(values.next().get());
        }
        StockAvg avg = new StockAvg();
        avg.setSymbol(key.toString());
        avg.setAvg(mean.getResult());
        output.collect(new AvroWrapper<StockAvg>(avg),
            NullWritable.get());
      }
    }
  }
  