Re: [gentoo-java] Java installation handling not acceptable

[Joshua Nichols]

Daniel wrote:
> Hi,
> the installation of Java on Gentoo is the hell on earth!
>
I'm sure lots of people would disagree. In fact, I do hear fairly often
that our support of Java very good.
> - the installation is non transparent
>
Care to elaborate? If you emerge java packages, things should just work,
ie the appropriate JDK will be pulled for building.
> - the java-"help"-utils (java-config, java-config-wrapper) are not acceptable,
> because you don't really need them
>
How are they not acceptable? They are absolutely necessary actually, as
they are used for configuring and building Java on Gentoo
> - the whole solution of installing more than one jdk is bumptious - so not
> easy
> handable
>
I... really don't get what you saying. According to the handy
dictionary.reference.com site, bumptious means 'Crudely or loudly
assertive; pushy.' I don't really how supporting multiple JDKs is pushy
or supportive. It just offers a lot more flexibility. In particular, it 
gives a lot of power when it come time for a new Java release, such that
we can use the stable and widely used version, while all the issues with
various packages are being worked out with the new version.
> This meens that it takes long time to install java and that you need to do
> some
> terrible thinks (e.g. unmasking some packages ... see
> http://www.gentoo.org/proj/en/java/java-upgrade.xml).
>
Terrible thinks? It is a new system for handling Java.... so of course
it needs to be in testing keywords. Or perhaps would you prefer it were
marked stable and then have all sorts of fun breakages for our stable
packages? No one forces you to unmask anything. Most times people using
stable keywords run into the new Java system because they decided to
package.unmask Java 1.5. (And please note, there is a difference between
using testing keywords, ie ~x86, and using stuff in package.mask... the
latter are known to cause problems or are undergoing heavy testing)
> This is not the way gentoo should go because this is to heavy for the user
> (that mostly just wants to install a jdk :) )!
>
If you don't have anything Java related installed, you can just emerge
the JDK. If you do have Java stuff installed, chances are you already
have one installed, and nothing is stopping you from emerging a
different one.
> So I have collected some points _we_ should think about:
> - why is jdk-1.5 still under development?
>
http://www.gentoo.org/proj/en/java/tiger-faq.xml should spell out some
of it. And I'm not sure what you mean by under development. I presume
you mean testing keywords? If so, this is standard policy, because it
1.5 has only recently come out of package.mask.
> - is it really necessary to install an jdk-1.4 and jdk-1.5? - if yes, why you
> don't need to install jdk-1.3?
>
Yes, it REALLY is necessary. First off, some packages are known to break
with Java 1.5. These will eventually can be patched. Second, every
package not using the new Java system needs to be built with Java 1.4 to
avoid the problems mentioned in the FAQ. It isn't necessary to install
1.3 because apparently, everything works with Java 1.4 that worked with
Java 1.3.
> - gentoo should never make a difference between jdk 1.4 and 1.5
>
Um... no. There does need to be a difference. I'm going to assume that
you just aren't familar enough with the differences between the two.
Just a few points:

* There is a different version of bytecode between major revisions of
JDKs, ie from 1.3 to 1.4, 1.4 to 1.5. Bytecode is forward compatible (ie
use 1.4 bytecode in 1.5 JRE), but not backward compatible.
* There is a new keyword, enum. Therefore, code using enum as a variable
code fails to compile
* Java 1.5 has new APIs for XML at least. It introduces new abstract
methods on some abstract classes and interfaces. The result is that when
classes fail to compile which use these abstract classes and interfaces,
and haven't specifically update to support the new API
> - java-config should just generate some environment files to set a special vm
>
What's a special VM?
> - if an ebuild requires a special vm (why ever, because the api of the jdk is
> compatible in most points) it should gnerate a warning, that the vm should be
> set to 1.x
>
See my previous points about compatibility.
> - it is the problem of the user if there are two java applications which need
> different vms (this problem is much easier to solve than installing java ;)).
>
>
The new Java system actually handles this. We basically create
'launchers' for this, which read information about the packages it
needs, and figures out if it can run in the current VM. If it doesn't,
it will switch to one.
> I hope you will not understand this bug as an act of aggression - it should
> just help Gentoo.
>
I hope you understand that it is easy to misunderstand comments to the
effect of 'Java on Gentoo being hell on earth' as being aggressive.

-- 
Joshua Nichols
Gentoo/Java - Project Lead

-- 
gentoo-java@g.o mailing list