Looks you are not using any compression in your code. Hadoop has some native
libraries to load mainly for compression codecs.
When you want to use that compression tequniques, you need to compile with this
compile.native option enable. Also need to set in java library path. If you are
not using any such stuff, then you need not worry about that warning.
Please look at the below link for more information.
http://hadoop.apache.org/common/docs/current/native_libraries.html
Regards,
Uma
________________________________________
From: Bing Li [lbl...@gmail.com]
Sent: Tuesday, February 07, 2012 3:08 PM
To: common-user@hadoop.apache.org
Subject: Unable to Load Native-Hadoop Library for Your Platform
Dear all,
I got an error when running a simple Java program on Hadoop. The program is
just to merge some local files to one and put it on Hadoop.
The code is as follows.
......
Configuration conf = new Configuration();
try
{
FileSystem hdfs = FileSystem.get(conf);
FileSystem local = FileSystem.getLocal(conf);
Path inputDir = new Path("/home/libing/Temp/");
Path hdfsFile = new
Path("/tmp/user/libing/example.txt");
try
{
FileStatus[] inputFiles =
local.listStatus(inputDir);
FSDataOutputStream out =
hdfs.create(hdfsFile);
for (int i = 0; i < inputFiles.length; i ++)
{
System.out.println(inputFiles[i].getPath().getName());
FSDataInputStream in =
local.open(inputFiles[i].getPath());
byte buffer[] = new byte[256];
int bytesRead = 0;
while ((bytesRead =
in.read(buffer)) > 0)
{
out.write(buffer, 0,
bytesRead);
}
in.close();
}
out.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
catch (IOException e)
{
e.printStackTrace();
}
......
I run it with ant and got the following warning. BTW, all the relevant jar
packages from Hadoop are specified in the build.xml.
[java] 2012-2-7 17:16:18 org.apache.hadoop.util.NativeCodeLoader
<clinit>
[java] Warning: Unable to load native-hadoop library for your
platform... using builtin-java classes where applicable
The program got a correct result. But I cannot figure out what the above
problem is.
Thanks so much!
Bing
