Error: Could not find or load main class org.codehaus.classworlds.Launcher

$ which mvn

$ sudo apt-get install maven

$ mvn -version

The command apt-get install the Maven in /usr/share/maven, then

export M2_HOME=/usr/share/maven
export M2=%M2_HOME%\bin

PATH=$PATH:$JAVA_HOME
PATH=$PATH:$M2
export PATH


http://www.cubeia.com/2009/02/10-sure-signs-you-are-doing-maven-wrong/