Hadoopメーリングリスト

どうやって，HDFSのライブラリを使うの？という質問に．以下のようなソースが流れてました．んー，シンプル．

import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.conf.Configuration;

import java.io.IOException;

public class ReadWrite{
  public static void main(String[] args) throws IOException{
      FileSystem hdfs = FileSystem.get(new Configuration());

      Path path = new Path("/testfile");

      //writing
      FSDataOutputStream dos = hdfs.create(path);
      dos.writeUTF("Hello World");
      dos.close();

      //reading
      FSDataInputStream dis = hdfs.open(path);
      System.out.println(dis.readUTF());
      dis.close();

      hdfs.close();
  }
}

I'm assuming that you have in your classpath the hadoop-site.xml file
correctly configured, meaning that the property "fs.default.name" has a
valid name node for your cluster, or you could use FileSystem.getLocal()
for local file system.

John