Java classpath - Linux
I think you should not put any paths that a local to your home directory in a system wide file. I would leave /etc/environment well alone, unless you provide some changes, that are necessary or beneficial to all users.Put any changes to the CLASSPATH in your .bashrc in your home directory.
CLASSPATH=$CLASSPATH:/home/foo:/home/foo/Java_code/my_code export CLASSPATHThis way you can source it and any newly started bash will have the settings right at once.