public static void recursePath(Configuration conf, Path path, Job job) {
   try {
     FileSystem fs = path.getFileSystem(conf);
     FileStatus[] fstats = fs.listStatus(path);
     if (fstats != null) {
       for (FileStatus f : fstats) {
         Path p = f.getPath();
         ;
         if (fs.isFile(p)) {
           // connection times out otherwise
           System.err.println("file:" + p.toString());
           FileInputFormat.addInputPath(job, p);
         } else {
           System.err.println("dir:" + p.toString());
           recursePath(conf, p, job);
         }
       }
     }
   } catch (IOException e) {
     // shouldn't be here
     throw new RuntimeException(e);
   }
 }
  public int run(String[] args) throws IOException, ClassNotFoundException, InterruptedException {

    if (args.length != 2) {
      System.out.println("Usage: FeatureMatching ID <inputName.jpeg/inputName.jpg>");
      System.exit(1);
    }

    SimpleDateFormat sdf = new SimpleDateFormat("", Locale.US);
    sdf.applyPattern("yyyy-MM-dd_HH-mm-ss");
    String time = sdf.format(new Date());

    Job job = Job.getInstance();

    ID = "/" + args[0];
    String filename = args[1];
    filename = filename.toLowerCase();
    System.out.println("current filename:" + filename);

    // Detect illegal username (if the username dir doesn't exist)
    File userPath = new File(LOCAL_USER_DIR + ID);
    if (!userPath.exists()) {
      System.out.println("Unauthorized username!!!\nExiting......");
      System.exit(1);
    }
    // Preprocess the input image.jpg from local dir: /local.../user/ID/input/image.jpg
    // Save the features to local dir: hdfs://.../user/ID/input/image.jpg
    extractQueryFeatures2HDFS(filename, job);

    // Add the feature file to the hdfs cache
    String featureFileName = filename.substring(0, filename.lastIndexOf(".")) + ".json";
    //        job.addCacheFile(new Path(HDFS_HOME + USER + ID + INPUT + "/" +
    // featureFileName).toUri());
    job.getConfiguration()
        .set("featureFilePath", HDFS_HOME + USER + ID + INPUT + "/" + featureFileName);

    // Check the file type. Only support jpeg/jpg type images
    String type = filename.substring(args[1].lastIndexOf("."));
    if (!(type.equals(".jpg") || type.equals(".jpeg"))) {
      System.out.println("Image type not supported!!!\nExiting");
      System.exit(1);
    }

    // Input: hdfs://.../features/
    // The feature dir is a location of all features extracted from the database
    String inputPathStr = HDFS_HOME + FEATURES;
    // Output: hdfs://.../user/ID/output/
    String outputPathStr = HDFS_HOME + USER + ID + OUTPUT + "/" + time;

    job.setInputFormatClass(KeyValueTextInputFormat.class);
    //        job.setOutputFormatClass(TextOutputFormat.class);

    // Get the lists of all feature files: /.../features/data/part-*
    FileSystem fs = FileSystem.get(job.getConfiguration());
    FileStatus[] statuses = fs.listStatus(new Path(inputPathStr));
    StringBuffer sb = new StringBuffer();
    for (FileStatus fileStatus : statuses) {
      sb.append(fileStatus.getPath() + ",");
    }
    sb.deleteCharAt(sb.lastIndexOf(","));

    job.setJarByClass(FeatureMatching.class);
    job.setMapperClass(FeatureMatchMapper.class);
    job.setReducerClass(FeatureMatchReducer.class);

    // only need one reducer to collect the result
    job.setNumReduceTasks(1);

    job.setMapOutputKeyClass(IntWritable.class);
    job.setMapOutputValueClass(Text.class);

    job.setOutputKeyClass(Text.class);
    job.setOutputValueClass(DoubleWritable.class);

    // Input a directory, so need the recursive input
    FileInputFormat.setInputDirRecursive(job, true);
    // Set the PathFilter, to omit _SUCCESS files
    // (This is not working correctly, as the PathFilter class is an interface rather than a class.
    // But the 2nd arg asks me to extend the PathFilter)
    //        FileInputFormat.setInputPathFilter(job, MyPathFilter.class);
    //
    //        FileInputFormat.setInputPaths(job, new Path(inputPathStr));
    FileInputFormat.setInputPaths(job, sb.toString());
    FileOutputFormat.setOutputPath(job, new Path(outputPathStr));

    boolean success = job.waitForCompletion(true);
    return success ? 0 : 1;
  }