[Fedora-packaging] Java packaging guidelines draft

[Jesus M. Rodriguez]

On Thu, Mar 27, 2008 at 11:59 AM, Nicolas Mailhot
<nicolas.mailhot at laposte.net> wrote:
>
>  Le Jeu 27 mars 2008 15:57, Thomas Fitzsimmons a écrit :
>
> > Ville Skyttä wrote:
>
>  > Yes, I've struggled to understand the same decision in the JDK
>  > packages.
>  >     I wonder why the extra level of versioning is required:
>  >
>  > $ ls -l /usr/lib/jvm/java-1.7.0-icedtea
>  > lrwxrwxrwx 1 root root 26 2007-12-11 14:36
>  > /usr/lib/jvm/java-1.7.0-icedtea -> java-1.7.0-icedtea-1.7.0.0
>  >
>  > Nicolas, do you know the rationale?  To enable parallel-installation
>  > of multiple versions of the same JDK, perhaps?
>
>  When you are in closed JVM hell you need to manage black-boxes and for
>  this reason switching between different JVMs (or different builds of
>  the same JVM) is very common (talking from an ISV perspective which
>  was my job when I wrote the guidelines). You can't trust the vendor to
>  fix its bugs timely. You can't trust it not to create regressions in a
>  new build (that will take forever to ve fixed). All you can do it get
>  a range of jvms and switch between them till you identify the most
>  solid.
>
>  When openjdk gets solid enough people trust the OS jvm, and when java
>  projects get the clue they need to work with any JVM not just the
>  particular build they copied in their private build system, I expect
>  those possibilities to gradually fall into disuse. But right now easy
>  JVM switching is a must for users.


Another reason for parallel JVM installation is when you're working on
different releases of a product that requires different JVM levels.
For instance,
I might have one that is certified to use 1.4.2 and another that requires 1.6.0.
I might be able to run my 1.4.2 under 1.6.0 but that's not always feasible.

jesus rodriguez