Goal: Increased Modularity?

[Richi Plana]

On Thu, 2007-09-06 at 23:05 -0500, Les Mikesell wrote:

> Is there some problem running an application where the bytecode is on a 
> different machine than the jvm, using nfs?

No, of course not. That's what applets are designed for. Same with
NFS-exported applications, but I'm thinking as real-world usage go, it's
much less likely. But then, that's why there are overrides like --nodeps
on rpm, I guess, just not on yum.

> > There is a huge probability
> > that they will need a JVM, and unlike media players, from outside,
> > they're designed to function in the same way.
> 
> I'm not sure I understand.  Shouldn't you be able to use any version of 
> a jvm, packaged or not, without specific dependencies, just like you 
> could use different media players to play the same file? Or even run 
> more than one of them at once?

Sorry, that was a bit vague. I just meant that a piece of java bytecode
is usually designed to be executed in one way (either as a java
application, web application, applet, etc.) or 2 or 3 at the most. Media
files can be used in so many ways, not just playing them (editing,
converting, analysis, etc.) Anyway, the point is that it's just not the
best example to illustrate your point, and not that it doesn't.

> > In Fedora, openoffice.org-core-2.2.0 Requires the virtual package java.
> > 
> > You CAN have the app before the JVM, I suppose, the same way you can
> > "rpm --nodeps -ivh openoffice.org-core.2.2.0....", but they'd just be
> > bytes taking up space in your filesystem.
> 
> Will it work later then if I provide a different JVM than the packaged 
> versions?

If both openoffice.org-core's Java requirements match those that the JVM
installed's featureset provides, then yes. (And better if it's because
they fully comply with JSRs for that version of Java(TM)). That's the
beauty of modularity.

> Yes, thanks, and sorry - I missed the one actual answer in the first 
> link, but I was confused by the comment somewhere about parts going to 
> private and export directories that didn't seem to be under the same top 
> level. Is everything expected to be under JAVA_HOME actually still in 
> one place?

I honestly don't know. 1) So far, it's worked for me, 2) looking at the
contents of the JRE (java-1.5.0-(sun|ibm)), it seems that apart from a
couple of JAR files located in jvm-exports/ and jvm-private/, all the
files are in (quotes) "$JAVA_HOME". Anybody read the pertinent JSR on
JAVA_HOME directory layouts care to comment?
--

Richi Plana