title: How to use JobControl in hadoop
body: <p>I want to merge two files into one.
  I made two mappers to read, and one reducer to join.</p>
  
  <pre><code>        JobConf classifiedConf = new JobConf(new Configuration());
              classifiedConf.setJarByClass(myjob.class);
      classifiedConf.setJobName("classifiedjob");
      FileInputFormat.setInputPaths(classifiedConf,classifiedInputPath );
      classifiedConf.setMapperClass(ClassifiedMapper.class);
      classifiedConf.setMapOutputKeyClass(TextPair.class);
      classifiedConf.setMapOutputValueClass(Text.class);
      Job classifiedJob = new Job(classifiedConf);
      //first mapper config
  
      JobConf featureConf = new JobConf(new Configuration());
      featureConf.setJobName("featureJob");
              featureConf.setJarByClass(myjob.class);
      FileInputFormat.setInputPaths(featureConf, featuresInputPath);
      featureConf.setMapperClass(FeatureMapper.class);
      featureConf.setMapOutputKeyClass(TextPair.class);
      featureConf.setMapOutputValueClass(Text.class);
      Job featureJob = new Job(featureConf);
              //second mapper config
  
      JobConf joinConf = new JobConf(new Configuration());
      joinConf.setJobName("joinJob");
              joinConf.setJarByClass(myjob.class);
      joinConf.setReducerClass(JoinReducer.class);
      joinConf.setOutputKeyClass(Text.class);
      joinConf.setOutputValueClass(Text.class);
      Job joinJob = new Job(joinConf);
               //reducer config
               //JobControl config
              joinJob.addDependingJob(featureJob);
      joinJob.addDependingJob(classifiedJob);
      secondJob.addDependingJob(joinJob);
      JobControl jobControl = new JobControl("jobControl");
      jobControl.addJob(classifiedJob);
      jobControl.addJob(featureJob);
      jobControl.addJob(secondJob);
  
      Thread thread = new Thread(jobControl);
      thread.start();
      while(jobControl.allFinished()){
          jobControl.stop();
      }
  </code></pre>
  
  <p>But, I get this message:
  WARN mapred.JobClient: </p>
  
  <pre><code>Use GenericOptionsParser for parsing the arguments. Applications should implement Tool for the same.
  WARN mapred.JobClient: No job jar file set.  User classes may not be found. See JobConf(Class) or JobConf#setJar(String).
  </code></pre>
  
  <p>anyone help please..................</p>