SequenceFileProtobufWriter.java

package hip.ch3.seqfile.protobuf;

import hip.ch3.proto.StockUtils;
import hip.util.Cli;
import hip.util.CliCommonOpts;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.compress.DefaultCodec;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;

import java.io.File;

import static hip.ch3.proto.StockProtos.Stock;

public class SequenceFileProtobufWriter 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 SequenceFileProtobufWriter(), args);
    System.exit(res);
  }

  /**
   * Write the sequence file.
   *
   * @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;
    }

    File inputFile = new File(cli.getArgValueAsString(CliCommonOpts.MrIoOpts.INPUT));
    Path outputPath = new Path(cli.getArgValueAsString(CliCommonOpts.MrIoOpts.OUTPUT));

Configuration conf = super.getConf();

ProtobufSerialization.register(conf);

SequenceFile.Writer writer =
    SequenceFile.createWriter(conf,
        SequenceFile.Writer.file(outputPath),
        SequenceFile.Writer.keyClass(Text.class),
        SequenceFile.Writer.valueClass(Stock.class),
        SequenceFile.Writer.compression(
            SequenceFile.CompressionType.BLOCK,
            new DefaultCodec())
    );
try {
  Text key = new Text();

  for (Stock stock : StockUtils.fromCsvFile(inputFile)) {
    key.set(stock.getSymbol());
    writer.append(key, stock);
  }
} finally {
  writer.close();
}
    return 0;
  }
}