Whenever I execute the command : hadoop jar wc.jar WordCount text.txt output It gives me this error
Exception in thread "main" java.lang.ClassNotFoundException: WordCount
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.apache.hadoop.util.RunJar.run(RunJar.java:316)
at org.apache.hadoop.util.RunJar.main(RunJar.java:236)
Even though everything seems to be fine
Can anyone help me out with this ??
CodePudding user response:
first of all you need to make sure you have a main method inside the WordCount class. You can also look at this answer right here: How to run a jar file in hadoop? As the answers suggest there's no problem when running the jar, but when creating the jar. So for example, you need to run:
JAVA_HOME/bin/jar cf WordCount.jar WordCount.class
and then run
hadoop jar WordCount.jar WordCount
Hope this helps.