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Is it possible to obtain a web-browser's Java VM without using an applet?

Answer 1

+1 A:

Q1: no

Q2: yes, but I don't know how portable that is:

<html><head><title>Test</title>
</head><body>
<script type="text/javascript">
document.writeln('<table border="1">');
for (var i = 0; i < navigator.plugins.length; i++) {
  document.writeln("<tr>");
  document.writeln("<td>" + navigator.plugins[i].name + "<\/td>");
  document.writeln("<td>" + navigator.plugins[i].description + "<\/td>");
  document.writeln("<td>" + navigator.plugins[i].filename + "<\/td>");
  document.writeln("<\/tr>");
}
document.writeln("<\/table>");
</script>
</body></html>

That outputs a table of all plugins, versions should be contained. I think you have to loop over all the plugins, check if 'java' is contained in the name and then parse the version from description...

Johannes Weiß 2009-02-06 21:08:54

Up-voted for the short, but sweet, answer to Q1 - that's what I thought.Unfortunately, Q2 doesn't appear to port as far as IE6 - mine's getting navigator.plugins.length as 0 :-(

raimesh 2009-02-06 21:15:54

A german website says it is supported in JavaScript 1.1, Netscape 3.0, Opera 5.12, Firefox 1.0, Konqueror 3.1, Safari 1 and higher and (exactly) IE for Mac 5.0 :-(.Perhaps any of all these JS libs has something for that...

Johannes Weiß 2009-02-06 21:33:15

Answer 2

+1 A:

There is a deployment toolkit for doing this sort of thing.

Serving an applet shouldn't be too bad. It can either be a 1x1 pixel bug, or use your normal applet with a small 1.1 class that forwards the applet lifecycle methods if it can load your 1.5 code.

Nobody should still be using 1.1. It hasn't had security bugs fixed in it for years.

Tom Hawtin - tackline 2009-02-07 00:12:15

We actually already serve an applet to determine the VM as we have two versions, one of which works around bugs in MS JVM (but doesn't work on Sun) and one of which is the other way round. The powers that be think this approach is too clunky going forward, so I'm tasked with looking for another way.

raimesh 2009-02-07 22:12:33

Oh, and just because nobody *should* be using 1.1, this does not mean none of our customers *are* using 1.1, unfortunately :-(

raimesh 2009-02-07 22:47:25

Answer 3

A:

This script seems to do the trick on all major browsers:

http://www.pinlady.net/PluginDetect/JavaDetect.htm

mercator 2009-02-07 02:03:04

Seems quite complex considering it might run an applet anyway for its "NOTF" approach; we might as well just go straight to that option. Plus I'm not sure I want to run code written by someone who uses the idiom "Java142Installed = Java142Status == 1 ? true : false"

raimesh 2009-02-07 22:33:36

Well, I have to admit I didn't go beyond testing it actually worked.

mercator 2009-02-16 18:58:01

Answer 4

+1 A:

I think the deployment toolkit might do what you want.

Use the runApplet() function in deployJava to ensure that a minimum Java Runtime Environment is available on a client machine before launching the applet.

Jason Day 2009-02-07 02:05:06

Looks like the deployment toolkit is the "proper" way forward, so I've accepted this answer as it included a link to the appropriate page (sorry, tackline - I know you suggested the toolkit first, but them's the breaks).Meanwhile, we'll be using our tried-and-tested launch an applet approach!

raimesh 2009-02-25 18:12:50

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Is it possible to obtain a web-browser's Java VM without using an applet?

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