and welcome to LQ.
I don't know what exactly the RPM
does during the installation. But the
binaries only put the actual SDK in
your filesystem, but don't come with
any startup scripts.
If you search
find several answers to that question.
In brief you'll need to put the path's
to hte binaries in either the system
wide configuration files (/etc/profile,
or creating /etc/profile.d/java.sh - I
prefer the second technique since
it will still work if you install an upgrade
of your linux) or in your users ~/.bash_rc