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From felix gao <gre1...@gmail.com>
Subject Re: noobie question on hadoop's NoClassDefFoundError
Date Tue, 17 Nov 2009 18:17:52 GMT
I got it. try to include all the jar files in the hadoop's lib and ivy
folder. It fixed mine.

On Tue, Nov 17, 2009 at 10:12 AM, Ratner, Alan S (IS)
<Alan.Ratner@ngc.com>wrote:

>  I get a similar “NoclassDefFoundError” but it doesn’t involve Eclipse.  I
> have downloaded Hadoop 18.3, 19.1 and 20.1 and have gotten 18 and 19 to run
> on top of Cygwin.  But 20.1 doesn’t seem to be able to find Java, reports an
> exception in thread “main” java.lang.NoclassDefFoundError  and dies with the
> unhelpful message: “Could not find the main class: and.  Program will exit.”
>
>
>
> I have attached an image showing that the identical command (simply
> invoking bin/hadoop namenode -format) works in 18.3 and does not work in
> 20.1.  Does know why 20.1 differs this way from 18 and 19?
>
>
>
> Alan Ratner
>
>
>
>
>
> *From:* Jason Venner [mailto:jason.hadoop@gmail.com]
> *Sent:* Tuesday, November 17, 2009 1:26 AM
> *To:* mapreduce-user@hadoop.apache.org
> *Subject:* Re: noobie question on hadoop's NoClassDefFoundError
>
>
>
> Your eclipse instance doesn't have the jar files in the lib directory of
> your hadoop installation in the class path.
>
>  On Sat, Nov 14, 2009 at 7:51 PM, felix gao <gre1600@gmail.com> wrote:
>
> I wrote a simple code in my eclipse as
>
> Text t = new Text("hadoop");
> System.out.println((char)t.charAt(2));
>
> when I try to run this I got
>
> Exception in thread "main" java.lang.NoClassDefFoundError:
> org/apache/commons/logging/LogFactory
>     at org.apache.hadoop.io.Text.<clinit>(Text.java:49)
>     at com.example.io.WritableIOExample.main(WritableIOExample.java:44)
> Caused by: java.lang.ClassNotFoundException:
> org.apache.commons.logging.LogFactory
>     at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
>     at java.security.AccessController.doPrivileged(Native Method)
>     at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
>     at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
>     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
>     at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
>     at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
>     ... 2 more
>
> The library used are Haddop 0.20.1 and log4j-1.2.15
>
> Thanks for helping
>
>
>
>
> --
> Pro Hadoop, a book to guide you from beginner to hadoop mastery,
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