java_home directory is not correct though it exists in my environment file

I'm using Java jdk with Maven and I have the following /etc/environment

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

# Maven Settings
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

The /usr/local/jdk1.6.25 does exist, but when I run mvn -version I get...

Warning: JAVA_HOME environment variable is not set.
Apache Maven 3.0.3 (r1075438; 2011-02-28 17:31:09+0000)
Maven home: /usr/local/apache-maven/apache-maven-3.0.3
Java version: 1.6.0_23, vendor: Sun Microsystems Inc.
Java home: /usr/lib/jvm/java-6-openjdk/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux", version: "3.0.0-14-generic", arch: "i386", family: "unix"

does anyone know why this does not think my java_home directory is correct even though it exists in my environment file?

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.)