Bizzare web start problem

[JavaEnquirer]

My web start application only works on some client machines.
However, when I clear out the internet explorer cache on the problem
machines the problem disappears.

I heard something about Tomcat's no-cache directive being a problem.
Can anyone offer me some more explicit advice? I'm using Tomcat 5.5 and
can't find any reference to a no-cache directive in web.xml. I'm
assuming that by turning this off, IE will save my app to the client
machines' local file store and all will be well.

Here's what Sun had to say on the matter:

"This problem is specific to Internet Explorer. Although this can be
caused by a full cache, or turning off the cache in IE, it is usually
caused by a no-cache directive coming from either the web server or the
proxy server. IE will honor this directive, and not write the jnlp file
to disk, so Java Web Start cannot find it. This frequently happens when
upgrading a tomcat based server. Later versions set the no-cache
directive by default for any resource that is within a
security-constraint in web.xml. Try taking the relevant URI out of the
security constraint in web.xml."

http://java.sun.com/j2se/1.5.0/docs/guide/javaws/developersguide/faq.html#220

Many thanks in advance.

 

[Roedy Green]

"This problem is specific to Internet Explorer. Although this can be
caused by a full cache, or turning off the cache in IE, it is usually
caused by a no-cache directive coming from either the web server or the
proxy server. IE will honor this directive, and not write the jnlp file
to disk, so Java Web Start cannot find it. This frequently happens when
upgrading a tomcat based server. Later versions set the no-cache
directive by default for any resource that is within a
security-constraint in web.xml. Try taking the relevant URI out of the
security constraint in web.xml."

That is the strangest bug to survive so long in IE. It would mean ANY
download that is subsequently processed by some program would fail if
there were no caching. No-caching is a quite sensible option to warn
the browser to get it fresh every time.

 

[Roedy Green]

I heard something about Tomcat's no-cache directive being a problem.

you might look for a configuration file where the extensions, mime
types and freshness times are configured. No cache would mean a 0
freshness time.

Look for the phrase "explicit expiration time" in the docs with a
global grep.

 

[JavaEnquirer]

Thank you very much, I'll go take a look!