how does "javavms" work?

[Greg Lewis]

On Fri, May 11, 2012 at 02:36:12PM +0200, Alfred Bartsch wrote:
> Am 27.04.2012 20:53, schrieb Chad Leigh Shire.Net LLC:
> > Hi
> > 
> > Not the behind the scenes really.   Just how do I use it?
> > 
> > I installed OpenJDK7 from ports.  As part of that it installed the
> > Diablo stuff (Java 6).
> > 
> > the /usr/local/etc/javavms  file listed both.  But when I edited
> > this file to only have the OKDK 7 version, it still runs the Diable
> > JDK 6 stuff when I type "java" at the command line.
> > 
> > I read the man file on javavms and used registervm and unregistervm
> > and javavms only lists the OpenJDK 7 version but if I do
> > 
> > # java -version java version "1.6.0_07" Diablo Java(TM) SE Runtime
> > Environment (build 1.6.0_07-b02) Diablo Java HotSpot(TM) 64-Bit
> > Server VM (build 10.0-b23, mixed mode) #
> > 
> 
> Normally, the Diablo stuff is installed as a build dependency to
> compile the openjdk stuff, and can safely be removed afterwards.
> But you may keep both JVMS, or you may install even some more.
> In these cases javavmwrapper kicks in and lets you choose your
> preferred JVM.
> 
> Unfortunately, javavmwrapper behaves differently, whether it sees an
> installed portstree (/usr/ports/Mk/bsd.java.mk) or not.
> It is my experience that the wanted priority of JVMs due to
> /usr/local/etc/javavms is only guaranteed, if there is no portstree
> available.
> 
> So I decided to patch the javavm wrapper skript
> (/usr/local/bin/javavm) to remove these unwanted features. Now
> everything works for me as expected.
> 
> The attached patch file applies to an installed javavmwrapper-2.3.5
> port. You may alternatively just remove those lines from the script file.
> 
> HTH
> 
> P.S.: I'm thinking of filing a PR, since it looks like a bug.

It's definitely a feature rather than a bug, see javavm(1).

There are a number of knobs in the way of environment variables that you
can use to fiddle with the precedence of JVMs.

This is not to say javavm couldn't use a little updating.

-- 
Greg Lewis                          Email   : glewis at eyesbeyond.com
Eyes Beyond                         Web     : http://www.eyesbeyond.com
Information Technology              FreeBSD : glewis at FreeBSD.org