MapReduce Sample Code

MapReduce Sample Code

/*
 * DEMO Map/Reduce class test2
 * -- Convert GPDBFormat back to TEXT
 */
public static class Map_test2 extends Mapper<LongWritable, GPDBWritable,
  Text, NullWritable> { 
  public void map(LongWritable key, GPDBWritable value, Context context )
    throws IOException {
    try {
      context.write(new Text(value.toString()), NullWritable.get());
    } catch (Exception e) { throw new IOException (e.getMessage()); }
  }
}

public static void runTest2() throws Exception{
Configuration conf = new Configuration(true);
 Job job = new Job(conf, "test2");
 job.setJarByClass(demoMR.class);
 job.setInputFormatClass(GPDBInputFormat.class);
 job.setOutputKeyLClass (Text.class);
 job.setOutputValueClass(NullWritable.class);
 job.setOutputFormatClass(TextOutputFormat.class);
 job.setMapperClass(Map_test2.class);
     GPDBInputFormat.setInputPaths (job, 
     new Path("/demo/data/writeFromGPDB_42"));
 GPDBOutputFormat.setOutputPath(job, new Path("/demo/data/MRTest2"));
 job.waitForCompletion(true);
     
}