content: package hip.ch3.parquet;
  
  import com.google.common.collect.Lists;
  import hip.ch3.avro.gen.Stock;
  import hip.util.Cli;
  import hip.util.CliCommonOpts;
  import org.apache.avro.Schema;
  import org.apache.avro.generic.GenericRecord;
  import org.apache.avro.generic.GenericRecordBuilder;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.conf.Configured;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.mapreduce.Job;
  import org.apache.hadoop.mapreduce.Mapper;
  import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
  import org.apache.hadoop.util.Tool;
  import org.apache.hadoop.util.ToolRunner;
  import parquet.avro.AvroParquetInputFormat;
  import parquet.avro.AvroParquetOutputFormat;
  
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.List;
  
  public class AvroGenericParquetMapReduce 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 AvroGenericParquetMapReduce(), args);
      System.exit(res);
    }
  
    private static Schema avroSchema;
  
    static {
      avroSchema = Schema.createRecord("TestRecord", null, null, false);
      avroSchema.setFields(
          Arrays.asList(new Schema.Field("foo",
              Schema.createUnion(Arrays.asList(Schema.create(Schema.Type.DOUBLE), Schema.create(Schema.Type.NULL))),
              null, null)));
    }
  
    /**
     * 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();
  
      Job job = new Job(conf);
      job.setJarByClass(AvroGenericParquetMapReduce.class);
  
      job.setInputFormatClass(AvroParquetInputFormat.class);
      AvroParquetInputFormat.setInputPaths(job, inputPath);
  
      // force Avro to supply us GenericRecord objects in the mapper by mutating the
      // schema and changing the class name
      //
      Schema schema = Schema.createRecord("foobar",
          Stock.SCHEMA$.getDoc(), Stock.SCHEMA$.getNamespace(), false);
      List<Schema.Field> fields = Lists.newArrayList();
      for (Schema.Field field : Stock.SCHEMA$.getFields()) {
        fields.add(new Schema.Field(field.name(), field.schema(), field.doc(),
            field.defaultValue(), field.order()));
      }
      schema.setFields(fields);
  
      AvroParquetInputFormat.setAvroReadSchema(job, schema);
  
      job.setMapperClass(Map.class);
  
      job.setOutputKeyClass(Void.class);
      job.setOutputValueClass(GenericRecord.class);
  
      job.setOutputFormatClass(AvroParquetOutputFormat.class);
      FileOutputFormat.setOutputPath(job, outputPath);
      AvroParquetOutputFormat.setSchema(job, avroSchema);
  
      job.setNumReduceTasks(0);
  
      return job.waitForCompletion(true) ? 0 : 1;
    }
  
    public static class Map extends Mapper<Void, GenericRecord, Void, GenericRecord> {
  
      @Override
      public void map(Void key,
                      GenericRecord value,
                      Context context) throws IOException, InterruptedException {
        GenericRecord output = new GenericRecordBuilder(avroSchema)
            .set("foo", value.get("open"))
            .build();
  
        context.write(key, output);
      }
    }
  }
  