IcedTeaWeb Started application apparently tries to download classpath resources from server

[Christian Svedin]

Maybe I'm not explaining what I think might be a problem correctly.

As far as I can tell, the only thing webstart is supposed to download
from a server is what is listed in the jnlp, nothing else.
That's how I read this part of the webstart FAQ: https://docs.oracle.co
m/javase/8/docs/technotes/guides/javaws/developersguide/faq.html#s113

--------------------
Can I deploy any application with Java Web Start?

Java Web Start is an application launcher for Java applications that
are written to be web-deployed.

An application must be delivered in a set of JAR files and all
application resources, such as images, configuration files, and native
libraries must be included in the JAR files. The resources must be
looked up using the method ClassLoader.getResource() or an equivalent
method. Java Web Start only transfers JAR files from the web server to
the client.

If an application is written to run in a restricted execution
environment (sandbox), then access to disk is not permitted and the
application may only connect to the host on which it resides.
--------------------

But when I use IcedTea Webstart it tries to download all kinds of
files.
For example, it tries to load ResourceBundle properties files from the
server, where it might need to try a few names before finding the ones
to use which results in alot of extra server calls.

So what i suggest is that when the classloader looks for non-jar
resources it should not fall back to loading them from the server. Is
that reasonable?

/ Christian


On Thu, 2019-02-21 at 12:21 +0100, Jiri Vanek wrote:
> On 2/21/19 8:51 AM, Christian Svedin wrote:
> > 
> > On Wed, 2019-02-20 at 16:24 +0100, Jiri Vanek wrote:
> > > 
> > > Yes. Codebase is where your code is laying, and thus where ITW is
> > > searching for it.
> > > 
> > > On 2/20/19 2:12 PM, Christian Svedin wrote:
> > > > 
> > > > 
> > > > I have an application that is started using webstart. After the
> > > > application has started I get
> > > > logging on my server that says that something is trying to load
> > > > resources that doesn't exist.
> > > > 
> > > > To me it looks like my webstarted application is trying to load
> > > > classes/resources from the url that
> > > > is codebase in my jnlp.
> > > > 
> > > > For example, it seems like
> > > > getClass().getClassLoader().getResource("/missing/resource")
> > > > tries
> > > > to
> > > > load from http://my.application/webstart/missing/resource if my
> > > > codebase is
> > > > http://my.application/webstart
> > > Where else would you like it to look?
> > > 
> > I would prefer that it looks inside the resources listed in my
> > jnlp-
> And it is not doing so?
> > I have just tried in-jar resource, and it was tried first.
> > > 
> > file. Not trying to dynamically load classes from the codebase.
> > That's
> > how oracles webstart does it right?
> > 
> > If you expect it to load from jars, then you are right, and that is
> > first place it should look.
> > 
> > 
> > 
> > Does the classloader i get from icedtea-web behave the way I think?
> > Is this how it's supposed to
> > work? ��
> > 
> > If this is how it's supposed to work, doesn't this have quite big
> > performance implications?
> > 
> > 
> > / Christian
> > 
> > 
> > 
> > 
> > 
> > 
-- 
Ida Infront
Christian SvedinSystemutvecklare
Ida Infront AB | Box 576 | SE-581 07 Linköping | Swedenmobile 0702 09 22 40 | direct 013 37 37 47e-mail christian.svedin at idainfront.se | web www.idainfront.se