FAQ
Hi, Nick

I think the listStatus(Path) is really what I want.

Meanwhile, I also asked How to set the Configuration object when
constructing the FileSystem object. As I know, in order to make Hadoop
client programs runs (like ./hadoop fs ls / command), the hadoop
configuration files, e.g hadoop-default.xml and hadoop-sites.xml must be
parsed to obtain information of NameNode and DataNode.

So, If I'd like to run the directory traversal class as a standalone
Java application on a Machine rather than Nodes within the Hadoop
cluster, Do I need to copy hadoop configuration files to client side and
load them at runtime?

BR/anderson

-----Original Message-----
From: Nick Cen
Sent: Tuesday, June 16, 2009 1:19 PM
To: core-user@hadoop.apache.org
Subject: Re: How to use DFS API to travel across the directory tree and
retrieve content of a DFS file?

I think you can take a look at the following classes. FileSystem, Path,
FileStatus.

*and the listStatus(Path path)* method in FileSystem.



2009/6/16 Wenrui Guo <wenrui.guo@ericsson.com>
Hi, all


As I know, hadoop fs -ls / can list files and directory of root
directory, so I am wondering How could I write a Java program to
travel across the whole DFS directory structure?

That is, if the directory structure at the moment like the following:

/
+----home
+ anderson
+ samples.dat


Is it possible to write a Java program that can visit from the /
directory and list subdirectory, and find if it reaches a dat file?

Afterwards, how could I obtain the content of the samples.dat ? So
far, I know the starting point is constructing a Configuration object,
however, What's the necessary information should be included in the
Configuration object?
Shall I specify the hadoop-defaults.xml and hadoop-sites.xml inside it.
I'll appreciate if a simple sample program is provided.

BR/anderson


--
http://daily.appspot.com/food/

Search Discussions

Discussion Posts

Previous

Follow ups

Related Discussions

Discussion Navigation
viewthread | post
posts ‹ prev | 3 of 4 | next ›
Discussion Overview
groupcommon-user @
categorieshadoop
postedJun 16, '09 at 3:25a
activeJun 17, '09 at 4:40a
posts4
users2
websitehadoop.apache.org...
irc#hadoop

2 users in discussion

Wenrui Guo: 2 posts Nick Cen: 2 posts

People

Translate

site design / logo © 2022 Grokbase