Hi hansel!

 On 2015.01.29 at 19:30:33 -0500, hansel wrote next:

> If I download the Oracle rpm for 1.8, do the necessary links in
> /etc/alternatives, remove Open JDK 1.7 and make sure the enviroment
> variables are correct, do I avoid crashes (or silent errors) -- to the
> best
> of more experienced SL users' knowledge, of course?
>
> Some of what I do depends on Java version 1.8 andI need to do
> something. (On
> other distos, I would just do it (and did with Ubuntu), but SL7 docs
> carry
> strong warnings about introducting conflicts.)

You don't have to "remove" OpenJDK 1.7 if there is some dependency
installed. alternatives system allows multiple java versions to be
installed at the same time.

The warnings mostly apply to the way Oracle JDK is packaged, if you
correct the packaging there is no problem with having it on the system,
and no need to remove openjdk (if something depends on it) too.

For example, one of the Oracle JDK packaging problems is inability to
install both 32-bit and 64-bit JDK from rpm (official workaround:
"install from .bin bundle into distinct directories"). Another problem
is manual steps required for activating browser plugin.
OpenJDK doesn't suffer from these and other problems.

RHEL offers Oracle JDK 1.7 and 1.8 packages, for example, properly
repackaged and ready to install. So there is definitely no inherent
incompatibility.

-- 

Vladimir