Exception when I run a hadoop job in Eclipse

Question

I am trying to run a Hadoop wordcount job (I am using hadoop 2.6.0). When I export my project to runnable jar and run it from CLI it works. However when I launch it in Eclipse with "Run as java application" I receive the following exception:

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory at org.apache.hadoop.conf.Configuration.(Configuration.java:173) at WordCount.main(WordCount.java:54) Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) ... 2 more

Can anybody assist me with this issue?

cabad cabad · Accepted Answer · 2015-08-14T14:20:34

I think you have not properly configured Eclipse and it doesn't know where to find the Apache Commons libraries jars. From this tutorial, you may be missing the last steps:

To run tests from Eclipse you need to additionally do the following:

Under project Properties, select Java Build Path, and the Libraries tab

Click "Add External Class Folder" and select the build directory of the current project

You may also want to take a look at this other tutorial where it shows how/where to add the dependencies jars to run a Hadoop program.

Exception when I run a hadoop job in Eclipse

4 Answers