On Thu, 18 Jun 2009, Tim Jenness wrote:

> On Fri, 19 Jun 2009, Mark Taylor wrote:
> 
> > Distributing a 1.6 JRE (or even JDK) is not problematic.  Distributing
> > a starjava set which has been built using a 1.6 JDK may be somewhat
> > problematic, in that it means anybody wanting to use the
> > distributed jar files must be running 1.6, and not everybody is.
> > There's no reason in principle why you can't distribute a 1.6 J{RE,DK}
> > with a starjava set built using 1.5 (or 1.4), but I don't know if that's
> > what the current build/distribute setup is going to do.
> > 
> > The relevant facts are: it's all backwardly but not forwardly compatible,
> > so that a J{RE,DK} of version X can work with any classes/jar files
> > built using versions <=X, but not >X.
> > 
> > So, I'd prefer to ensure that the starjava build is done using 1.5
> > (or 1.4).  I don't necessarily demand this, but if you're going to
> > do different I'd like to know about it and make sure the implications
> > are clear.
> > 
> 
> My main issue is that I don't have a feel for how many people are using
> starjava jar files from the starlink distribution but using their own java.
> Especially in comparison with how many download from AstroGrid or build from
> the repository. If there is a large user community relying on the starlink
> distribution to get their stilts jar files, or whatever, then that would be
> reason to stick with 1.5 (which is what we've been using for a while - we
> aren't going back to 1.4). If starlink users are using splat and topcat as
> black boxes then it makes no difference.

I don't think there are many who intentionally mix and match - 
I recommend TOPCAT users etc to use the single jar downloads.  
However, it does happen at starlink sites (including here) that 
people end up using a java from one place and jar files from 
another, usually as a result of poorly configured or invoked 
.cshrc/.login files, mostly without realising this is what 
they're doing, and it results in confusing error messages.  
Easy for me to diagnose and fix, but not so easy for a hapless 
user who just types 'topcat' and gets a stacktrace.

But my point is there's no downside as far as users are concerned
to distributing 1.5-compatible starjava jar files with a 1.5 or 1.6
J{RE,DK}.  I don't know however whether it makes building the 
distribution more complicated - I wouldn't have thought much more, 
but I don't understand the build well enough to know.

Mark

-- 
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
[log in to unmask] +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/