하둡 테스트

 1. 테스트 프로그램 작성

% mkdir ~/work
% cd ~/work
% vi URLCat.java
import java.io.InputStream;
import java.net.URL;

import org.apache.hadoop.fs.FsUrlStreamHandlerFactory;
import org.apache.hadoop.io.IOUtils;

public class URLCat {

  static {
    URL.setURLStreamHandlerFactory(new FsUrlStreamHandlerFactory());
  }
  
  public static void main(String[] args) throws Exception {
    InputStream in = null;
    try {
      in = new URL(args[0]).openStream();
      IOUtils.copyBytes(in, System.out, 4096, false);
    } finally {
      IOUtils.closeStream(in);
    }
  }
}

2. 실행

javac URLCat.java -classpath /opt/cloudera/parcels/CDH/lib/hadoop/client/hadoop-common.jar
jar cvf URLCat.jar URLCat.class
hadoop jar URLCat.jar URLCat hdfs://server01.cloudera.cdh/user/{usename}/quangle.txt