Java Program to List Contents of Directory in Hadoop (HDFS)

How to list out the files and sub directories in the specified directory in Hadoop HDFS using java program?

The following java program prints the contents (files and directories) of a given directory(/user/hadoop) in HDFS:

/*Java Program to Print Contents of HDFS Directory*/
package in.blogspot.java2bigdata;

import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;

public class ListDirectoryContents {
  public static void main(String[] args) throws IOException, URISyntaxException
  {
    //1. Get the Configuration instance
    Configuration configuration = new Configuration();
    //2. Get the instance of the HDFS
    FileSystem hdfs = FileSystem.get(new URI("hdfs://localhost:54310"), configuration);
    //3. Get the metadata of the desired directory
    FileStatus[] fileStatus = hdfs.listStatus(new Path("hdfs://localhost:54310/user/hadoop"));
    //4. Using FileUtil, getting the Paths for all the FileStatus
    Path[] paths = FileUtil.stat2Paths(fileStatus);
    //5. Iterate through the directory and display the files in it
    System.out.println("***** Contents of the Directory *****");
    for(Path path : paths)
    {
      System.out.println(path);
    }
  }
}

In the above program, hdfs://localhost:54310 is the namenode URI.