Multiple JVMs; specifying the runtime lib

[Scott Edward Skinner]

Is it possible to specify the location of the Java runtime lib (i.e.,
jvm.dll) through an environmental variable or as a parameter passed to
java.exe?

I'd like to use a variety of JVMs on a test server without actually
installing any of them. By installing I mean running the installer
which creates a Windows Registry entry and thus a system-wide default
JVM. I want to manually specify which JVM to use through batch files.

In general, what is the best way to handle multiple JVMs?

-S

 

[Andrew Thompson]

In general, what is the best way to handle multiple JVMs?

Java Webstart.

--
Andrew Thompson
http://www.PhySci.org/codes/ Web & IT Help
http://www.PhySci.org/ Open-source software suite
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[Scott Edward Skinner]

I thought JWS was for client-side stuff like Applets. I'm talking
about multiple JVMs for QA--server-side stuff.

Is there a list of undocumented parameters beyond what "java -help"
provides?

-S

 

[Andrew Thompson]

On 16 Sep 2004 06:35:54 -0700, Scott Edward Skinner wrote:

Please don't top-post Edward, I find it most confusing..
<http://www.physci.org/codes/javafaq.jsp#netiquette>

See further comments in-line.

...
thought JWS was for client-side stuff like Applets.

or applications.

..I'm talking
about multiple JVMs for QA..

Question and Answer?
What has that to do with the conversation?

..--server-side stuff.

So, is this a web-service? Is it
defined in the web.xml file? Or are
these simply applications that run
on the server?

Is there a list of undocumented parameters ...

If there was a list, ..they would
then be documented.

...beyond what "java -help" provides?

No. 'batch files' is not the way to go here
in any case. I am not sure how to do it if
you are talking anout a web-service, but for
applications, WebStart has all you need.

You can specify not only a minimum version,
but even specific micro-versions of the JRE.

They are 'installed' in that if the requested
JRE is not present, it will be downloaded and
installed, but it does not 'take over' as the
main JRE in the way it would if you install a
different Java version yourself.

--
Andrew Thompson
http://www.PhySci.org/codes/ Web & IT Help
http://www.PhySci.org/ Open-source software suite
http://www.1point1C.org/ Science & Technology
http://www.lensescapes.com/ Images that escape the mundane

 

[Andrew Thompson]

On 16 Sep 2004 06:35:54 -0700, Scott Edward Skinner wrote:

Please don't top-post Edward, I find it most confusing..

Ooops! Sorry, Scott.

( now, ..you see how *easily* I get confused. ;-)

 

[Tim Jowers]

Is it possible to specify the location of the Java runtime lib (i.e.,
jvm.dll) through an environmental variable or as a parameter passed to
java.exe?
yes.


I'd like to use a variety of JVMs on a test server without actually
installing any of them. By installing I mean running the installer
which creates a Windows Registry entry and thus a system-wide default
JVM. I want to manually specify which JVM to use through batch files.

In general, what is the best way to handle multiple JVMs?

Pick the fastest one.

-S

Seriously, java.exe is the exectuable. Executables are found via PATH.
"set PATH" works in Windows and Linux/Unix. Or even launch using
chosen JVM.

Also you should check out the performance.

java -verbosegc
or something like
java -Xhperf or whatever the command is.

Have a blast,
TimJowers

 

[Scott Edward Skinner]

(e-mail address removed) (Tim Jowers) wrote in message

Seriously, java.exe is the exectuable. Executables are found via PATH.
"set PATH" works in Windows and Linux/Unix. Or even launch using
chosen JVM.

Seriously, I know all this. Have you tried this yourself? Uninstall
every reference to Java from your Windows Registry. Then copy the
j2sdk1.4.2_05 folder to your HD. Then set all the environmental
variables you want; you know; things like JAVA_HOME and PATH and
CLASSPATH. Then try to run HelloWorld...

<insert my original question here>

-S

 

[Andrew Thompson]

<insert my original question here>

<insert my original answer here>

 

[Scott Edward Skinner]

On 16 Sep 2004 06:35:54 -0700, Scott Edward Skinner wrote:

Please don't top-post Edward, I find it most confusing..
<http://www.physci.org/codes/javafaq.jsp#netiquette>

See further comments in-line.


or applications.


Question and Answer?

QA = Quality Assurance.
Q&A = Question and Answer.

What has that to do with the conversation?

QA is fairly relevant to any development process...

So, is this a web-service? Is it
defined in the web.xml file? Or are
these simply applications that run
on the server?

Servlets. JSPs. That sort of thing.

If there was a list, ..they would
then be documented.

I'm using undocumented in the sense of something that is not widely
known or distributed.

No.

Are you certain of this? Absolutely certain?

 

[Andrew Thompson]

Servlets. JSPs. That sort of thing.

So, you're talking about the JVM used for
the Java based server?

I'm afraid that's a bit outside my field of
expertise, I expect it is more complicated
by the fact that these Servlets and JSP's are
being called from a JVM that is already loaded
and running.

I'm using undocumented in the sense of something that is not widely
known or distributed.


Are you certain of this? Absolutely certain?

I am 99% sure that I am absolutely certain about
nothing. I do offer a 'money back quarantee' though. ;-)

You are going to need to get one of the server
gurus into this conversation, but I am still
pretty sure that 'batch' files is not the way
to go.

--
Andrew Thompson
http://www.PhySci.org/codes/ Web & IT Help
http://www.PhySci.org/ Open-source software suite
http://www.1point1C.org/ Science & Technology
http://www.lensescapes.com/ Images that escape the mundane

 

[Scott Edward Skinner]

<insert my original answer here>

Your original answer was "Java Webstart" which is not relevant for
Servlets and JSPs.

I am 99% sure that I am absolutely certain about
nothing.

This, at any rate, seems accurate.

-S

 

[Andrew Thompson]

Your original answer was "Java Webstart" which is not relevant for
Servlets and JSPs.

Your original information was crap,
quoting from your posts..

2004-09-16 03:18am 'test server'
2004-09-16 11:35pm 'server-side stuff.'
2004-09-18 02:33am *
2004-09-18 02:45am 'Servlets. JSPs. That sort of thing.'

The asterisk indicates the time at which
I posted that response.

Can somebody hand me the group's crystal
ball please?

And while you are at it, get me the spoon.
This guy's got a silver one, but he says
he was born with it, and won't give it up.

This, at any rate, seems accurate.

Straight after the part of that post you quote, was..

Thank you for warning them not to waste their time,
their expertise is in lesser supply than the demand.

--
Andrew Thompson
http://www.PhySci.org/codes/ Web & IT Help
http://www.PhySci.org/ Open-source software suite
http://www.1point1C.org/ Science & Technology
http://www.lensescapes.com/ Images that escape the mundane