title: HADOOP :: java.lang.ClassNotFoundException: WordCount
body: <p>I am using eclipse to export the jar file of a map-reduce program. When i am run the jar using command </p>
  
  <pre><code> hadoop jar hadoop-prog.jar WordCount /home/temp/input /home/temp/output
  </code></pre>
  
  <p>it always shows the error :</p>
  
  <pre><code>   Exception in thread "main" java.lang.ClassNotFoundException: WordCount
      at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
      at java.lang.Class.forName0(Native Method)
      at java.lang.Class.forName(Class.java:247)
      at org.apache.hadoop.util.RunJar.main(RunJar.java:149)
  </code></pre>
  
  <p>Btw, I get a sample example jar file of wordcount from internet and it ran very well.</p>
  
  <p>I could not figure out where is the problem.</p>