private static String[] testFiles = new String[]     {"img01.JPG","img02.JPG","img03.JPG","img04.JPG","img06.JPG","img07.JPG","img05.JPG"};
 // private static String testFilespath = "/home/student/Desktop/images";
private static String testFilespath ="hdfs://localhost:54310/user/root/images";
//private static String indexpath = "/home/student/Desktop/indexDemo";
private static  String testExtensive="/home/student/Desktop/images";

public static class MapClass extends MapReduceBase
implements Mapper<Text, Text, Text, Text> {
private Text input_image = new Text();
private Text input_vector = new Text();
    @Override
public void map(Text key, Text value,OutputCollector<Text, Text> output,Reporter       reporter) throws IOException {

 System.out.println("CorrelogramIndex Method:");  
       String featureString;
int MAXIMUM_DISTANCE = 16;
AutoColorCorrelogram.Mode mode = AutoColorCorrelogram.Mode.FullNeighbourhood;
for (String identifier : testFiles) {
            try (FileInputStream fis = new FileInputStream(testFilespath + "/" +    identifier)) {
  //Document doc = builder.createDocument(fis, identifier);
//FileInputStream imageStream = new FileInputStream(testFilespath + "/" + identifier);
BufferedImage bimg = ImageIO.read(fis);
 AutoColorCorrelogram vd = new AutoColorCorrelogram(MAXIMUM_DISTANCE, mode);
                 vd.extract(bimg);
               featureString = vd.getStringRepresentation();
               double[] bytearray=vd.getDoubleHistogram();
              System.out.println("image: "+ identifier + " " + featureString );

        }
             System.out.println(" ------------- ");
input_image.set(identifier);
input_vector.set(featureString);
   output.collect(input_image, input_vector);
              }

     }
   }

  public static class Reduce extends MapReduceBase
  implements Reducer<Text, Text, Text, Text> {

    @Override
public void reduce(Text key, Iterator<Text> values,
                   OutputCollector<Text, Text> output, 
                   Reporter reporter) throws IOException {
  String out_vector="";

  while (values.hasNext()) {
   out_vector.concat(values.next().toString());
 }
  output.collect(key, new Text(out_vector));
  }
}

static int printUsage() {
System.out.println("image_mapreduce [-m <maps>] [-r <reduces>] <input> <output>");
ToolRunner.printGenericCommandUsage(System.out);
return -1;
}


@Override
  public int run(String[] args) throws Exception {
JobConf conf = new JobConf(getConf(), image_mapreduce.class);
conf.setJobName("image_mapreduce");

// the keys are words (strings)
conf.setOutputKeyClass(Text.class);
// the values are counts (ints)
conf.setOutputValueClass(Text.class);

conf.setMapperClass(MapClass.class);        
//  conf.setCombinerClass(Reduce.class);
conf.setReducerClass(Reduce.class);

List<String> other_args = new ArrayList<String>();
for(int i=0; i < args.length; ++i) {
  try {
    if ("-m".equals(args[i])) {
      conf.setNumMapTasks(Integer.parseInt(args[++i]));
    } else if ("-r".equals(args[i])) {
      conf.setNumReduceTasks(Integer.parseInt(args[++i]));
    } else {
      other_args.add(args[i]);
    }
  } catch (NumberFormatException except) {
    System.out.println("ERROR: Integer expected instead of " + args[i]);
    return printUsage();
  } catch (ArrayIndexOutOfBoundsException except) {
    System.out.println("ERROR: Required parameter missing from " +
                       args[i-1]);
    return printUsage();
  }
}



   FileInputFormat.setInputPaths(conf, other_args.get(0));
    //FileInputFormat.setInputPaths(conf,new    Path("hdfs://localhost:54310/user/root/images"));
FileOutputFormat.setOutputPath(conf, new Path(other_args.get(1)));

JobClient.runJob(conf);
return 0;
}


 public static void main(String[] args) throws Exception {
int res = ToolRunner.run(new Configuration(), new image_mapreduce(), args);
System.exit(res);
 }

}

`Eu estou escrevendo um programa que leva vários arquivos de imagem como entrada, armazenados em hdfs e extrair os recursos na função de mapa. Como posso especificar o caminho para ler a imagem em FileInputStream (alguns parâmetros)? Ou existe alguma maneira de ler os vários arquivos de imagem?

O que eu quero fazer é: - Levar vários arquivos de imagem em hdfs como entrada - extrair recursos na função de mapa. - Reduzir itearatively. Por favor me ajude no código ou melhores maneiras de fazer isso.