JWS Extensions, and Upgrading JRE/JDK

Question

We're using Java Web Start to deploy a java gui app, which needs third party libraries. One of these libraries is the Bouncy Castle crypto library, and signing issues mean we can't repackage this library into our main one, so we use the extension method, with a separate jnlp file etc. to copy the BC library to jre/lib/ext/
This works, and works well.
Until a client 'upgraded' their installation of the JRE. This client installed the latest 1.4.2 JRE "over the top" of the existing JRE (without uninstalling the old one).
As of that moment, our app refused to load. Because a new JRE had been installed, jre/lib/ext no longer contains the crypto library. And JWS doesnt notice.
I'd like a way of forcing JWS to install the extension, or at least to clear its extension cache so it reperforms the checks. Any ideas?

Answer 1

This is a well known problem. If you use extension installer to install files in jre/lib/ext. It will only be there for one update version.
One way around this is to just use a component extension instead of an installer-extension, that figures out itself where jre/lib/ext is, and checks if the jar is installed, and installs it if it is not there.
another way is to use specific installer extensions for each update release:
something like this:
<resources>
<j2se version="1.4.2_08" href="http://java.sun.com/products/autodl/j2se">
<resources>
<extension href="installer08.jnlp"/>
</resources>
</j2se>
<j2se version="1.4.2_09" href="http://java.sun.com/products/autodl/j2se">
<resources>
<extension href="installer09.jnlp"/>
</resources>
</j2se>
neither is a great solution, we should provide an easier method of addressing this in a future version of javaws
/Andy