Question

I keep getting this error when trying to enter “mvn -version in the cmd.

     Exception in thread "main" java.lang.NoClassDefFoundError: org/codehaus/plexus/c
     lassworlds/launcher/Launcher
     Caused by: java.lang.ClassNotFoundException: org.codehaus.plexus.classworlds.lau
     ncher.Launcher
     at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
     at java.security.AccessController.doPrivileged(Native Method)
     at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
     at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
     at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
     Could not find the main class: org.codehaus.plexus.classworlds.launcher.Launcher

. Program will exit.
‘cmd’ is not recognized as an internal or external command,

Answer 1

This is usually a problem with misconfiguring M2_HOME or M3_HOME. I’m not sure, but I think you can’t have both set. Also, do a “which mvn” – apparently some JVM installs will install a mvn in usr/bin.