[CentOS] java 1.6 and 1.7 on CentOS

Wed Aug 20 14:45:53 UTC 2014
Les Mikesell <lesmikesell at gmail.com>

On Wed, Aug 20, 2014 at 9:02 AM, Toralf Lund <toralf.lund at pgs.com> wrote:
>
>>>>> I can confirm that. I have both installed. You can configure the default
>>>>> using the 'alternatives' system.
>>>> is it just me, or does anyone else think that 'alternatives' system is
>>>> completely bogus?
>>> I've always seen it as designed mostly for system services for which
>>> there are several common implementations - like the SMTP server or the
>>> printing system. Where I think it makes sense.
>> But do you really need _two_ symlinks to get a default in your PATH?
> I think the argument is that "configuration" commands shouldn't change
> bin directories. Which is right in a way, but maybe this is one of the
> cases where practicality should have been chosen over formal correctness.

What is formally correct  about putting executables in some obscure
place under /var?

>>> It may also be useful to be able to set up a system-wide default for
>>> user applications "with alternatives", but I suppose a user override
>>> ought to be possible in that case.
>>>
>>>> what if I have one user that wants JDK6 and another that needs JDK7 ?
>>> I guess the "preferred applications" system in the desktop is in a way
>>> meant for such cases, but this of course comes across as incomplete, too.
>>>
>> The concept used for 'software collections' is a more realistic
>> approach - but instead of hiding where things land and needing a tool
>> to set up use, why not just tell people what to add to their own PATH
>> and LD_LIBRARY path to get the version you want.  That's almost
>> certainly what the developers of every package where they need to have
>> test versions does.  So why treat the users like they would be too
>> dumb for that?
> That's a point.
>
> You could also easily develop "config" tools that would make that job
> easier for "dumb" users - this might be more productive than maintaining
> different solution that essentially have the same effect.

Or you could just not pretend that users are dumb for choosing your
product.  And not hide the purpose, content, and functionality of PATH
and LD_LIBRARY_PATH, things that every developer who needs to have a
'stable, trusted' version of an application along with today's build
is going to understand and utilize.  So it's probably not those
developers that came up with the weird alternatives scheme - or at
least decided to use it for applications that really need concurrent
alternatives, not a site-wide default.

-- 
   Les Mikesell
      lesmikesell at gmail.com