Maven – Fixing Environment Variable Issues in Terminal

A couple ideas... First, just to reformat for readability, this is your PATH

PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

These are your env vars:

export JAVA_HOME=/usr/local/jdk1.6.25/
export M2_HOME=/usr/local/apache-maven/apache-maven-3.0.3
export M2=$M2_HOME/bin
export PATH=$M2:$PATH

Note that "java" (the program) is in $JAVA_HOME/bin, not $JAVA_HOME. That will cause a little confusion when a different 'java' is found in the shell's PATH. For example...

$ type java
java is /usr/bin/java

So just modify your PATH:

$ export PATH=$JAVA_HOME/bin:$PATH
$ type java
... should be $JAVA_HOME/bin/java ...

But I don't think that's the issue. From the mvn shell script launcher,

if [ -z "$JAVA_HOME" ] ; then
  echo "Warning: JAVA_HOME environment variable is not set."
fi

This would imply the var really isn't set -- not merely set to a wrong value. Perhaps this is the key hint:

[my java_home ...] even though it exists in my environment file?

Perhaps you added/modified JAVA_HOME to .bashrc or .profile , and then in the same shell tried to run mvn -v ?? If so, these values won't be picked up until you source the file (e.g., . ~/.bashrc ) or create a new login shell (bash -l) in order for these env var's to be set (or reset).

(Also... it's just a matter of opinion, but in your PATH, I'd leave the standard /usr/bin (and /usr/sbin and /bin) in front of any /usr/local/bin or /opt/bin (etc), just to avoid any rouge 'local' programs taking precedence over the standard programs... using something like alternatives would be preferable to override the default versions of standard applications.)

Add those export lines to your ~/.profile file.

If you want it to apply to all users on the system, put it in /etc/profile instead;

sudoedit /etc/profile

Once you've edited either, you'll see the effect next time you log in.

See also http://mywiki.wooledge.org/DotFiles

On a side-note, if you instead install maven via the software center or apt-get, you won't need to do any of the above.