content: package hip.ch4;
  
  import hip.util.Cli;
  import hip.util.CliCommonOpts;
  import org.apache.avro.generic.GenericRecord;
  import org.apache.avro.mapred.AvroInputFormat;
  import org.apache.avro.mapred.AvroJob;
  import org.apache.avro.mapred.AvroWrapper;
  import org.apache.commons.codec.digest.DigestUtils;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.conf.Configured;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.io.NullWritable;
  import org.apache.hadoop.io.Text;
  import org.apache.hadoop.mapred.*;
  import org.apache.hadoop.util.Tool;
  import org.apache.hadoop.util.ToolRunner;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  
  public class SmallFilesMapReduce 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 SmallFilesMapReduce(), 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;
      }
  
      String inputPath = 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(SmallFilesMapReduce.class);
  
      job.set(AvroJob.INPUT_SCHEMA, SmallFilesWrite.SCHEMA.toString());
  
      job.setInputFormat(AvroInputFormat.class);
  
      job.setOutputFormat(TextOutputFormat.class);
  
      job.setMapperClass(Map.class);
      FileInputFormat.setInputPaths(job, inputPath);
      FileOutputFormat.setOutputPath(job, outputPath);
  
      job.setNumReduceTasks(0);
  
      return JobClient.runJob(job).isSuccessful() ? 0 : 1;
    }
  
     public static class Map
        implements
         Mapper<AvroWrapper<GenericRecord>, NullWritable, Text, Text> {
  
       private Text outKey = new Text();
       private Text outValue = new Text();
  
      public void map(AvroWrapper<GenericRecord> key,
                      NullWritable value,
                      OutputCollector<Text, Text> output,
                      Reporter reporter) throws IOException {
        outKey.set(
          key.datum().get(SmallFilesWrite.FIELD_FILENAME).toString());
        outValue.set(DigestUtils.md5Hex(
              ((ByteBuffer) key.datum().get(SmallFilesWrite.FIELD_CONTENTS))
                .array()));
  
        output.collect(outKey, outValue);
      }
  
      public void close() throws IOException {
      }
  
      public void configure(JobConf job) {
      }
    }
  }