setting the JAVA_HOME environment variable

[Thufir]

what's the correct way to set the JAVA_HOME environment variable?

What I did was to add an entry to .bashrc for a specific profile.  Surely 
there's a better way?  This is only effective for one user and is fragile 
-- once Java 7 is installed the .bashrc is out of date and must be 
manually updated.

Perhaps I'm not installing packages correctly?  I'd just as soon 
uninstall all non-Sun java's (gcj and so forth).

I'm setting this variable to use the
http://incubator.apache.org/buildr/ ruby replacement for ant.

Here's what I have with the environment variable:



thufir at arrakis:~$ echo $JAVA_HOME
/usr/lib/jvm/java-6-sun/jre/bin/java
thufir at arrakis:~$ 
thufir at arrakis:~$ whereis javac
javac: /usr/bin/javac /usr/share/man/man1/javac.1.gz
thufir at arrakis:~$ 
thufir at arrakis:~$ ll /usr/bin/javac 
lrwxrwxrwx 1 root root 23 2008-03-19 02:39 /usr/bin/javac -> /etc/
alternatives/javac
thufir at arrakis:~$ 
thufir at arrakis:~$ java -version
java version "1.6.0_03"
Java(TM) SE Runtime Environment (build 1.6.0_03-b05)
Java HotSpot(TM) Client VM (build 1.6.0_03-b05, mixed mode, sharing)
thufir at arrakis:~$ 
thufir at arrakis:~$ sudo update-alternatives --config java

There are 2 alternatives which provide `java'.

  Selection    Alternative
-----------------------------------------------
          1    /usr/bin/gij-4.2
*+        2    /usr/lib/jvm/java-6-sun/jre/bin/java

Press enter to keep the default[*], or type selection number: 2
Using `/usr/lib/jvm/java-6-sun/jre/bin/java' to provide `java'.
thufir at arrakis:~$ 
thufir at arrakis:~$ cat -n .bashrc | head -n 16 | tail -n 4
    13
    14  JAVA_HOME="/usr/lib/jvm/java-6-sun/jre/bin/java"
    15  export JAVA_HOME
    16
thufir at arrakis:~$ 



thanks,

Thufir