New Maven install: mvn -version java.lang.ClassNotFoundException

Question

So I've installed maven with the following details:

Install path:

C:\Program Files\Apache Software Foundation\apache-maven-3.0.3

Env vars:

JAVA_HOME C:\Progra~1\Java\jdk1.6.0_25
M2_HOME C:\Program Files\Apache Software Foundation\apache-maven-3.0.3

User vars:

M2 %M2_HOME%\bin
PATH %JAVA_HOME%\bin;%M2%;

Now, from the command line

C:\>javac -version
javac 1.6.0_25

C:\>mvn -version
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$1.run(URLClassLoader.java:202)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
        at java.lang.ClassLoader.loadClss(ClassLoader.java:306)
        at sun.misc.Launcher$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.

I've been insulated from the command line build details for Java thus far thanks to Eclipse, but it looks like it's having problems with finding the plexus-classworlds-2.4.jar in the /boot dir. Should I need some additional path info?

Thanks!

Answer 1

I was able to resolve my issue with following when

export JAVA_HOME=/blah/blah
export M2_HOME=/usr/local/maven   
export M2=M2_HOME/bin

I was able to figure out looking at the folder name, it was 3.2.1

Perhaps, I didn't read document, but here's my answer to this problem.

export JAVA_HOME=/blah/blah
export M3_HOME=/usr/local/maven   
export M3=M2_HOME/bin

My java is 7. Hope this helps some people with Maven 3 instead of M2.

Answer 2

I had similar by having mvn.bat for maven2 in other part of PATH. So check carefully all directories of your PATH variable.