Java is not like Internet Explorer where there can be only one version for the entire OS. You can have multiple JDKs and/or JREs installed at once and pick which one to use on a per-application basis (although not a per-webapp basis, since web application servers are counted by the OS as a single Java app).
Therefore, assigning a JDE or JRE to the PATH depends on the shell instance.
I don't assign Java's PATH on a global basis, since apps such as Tomcat don't need Java in the path - the Tomcat control script simply uses the JAVA_HOME environment setting that was in effect when Tomcat was launched.
My development user account, however, does set (export) JAVA_HOME and adds $JAVA_HOME/bin to my PATH when I login or spawn a new shell process. I assign it in my .bashrc script, which isn't really the best place to put it out of the 8 or so possibilities, but it suffices for me.
Loudly announcing something is true and finding out you're wrong makes you feel foolish.
Finding out you're wrong and refusing to admit it makes you LOOK foolish.