Java apps that won't run in icedtea-web

So one of my requirements to replace Windows on a laptop that I carry around is that I have to be able to remote manage a number of SuperMicro servers with their own screwball KVM. It's java based, but it "knows" about Windows, OS/x and Linux -- and not FreeBSD.

You'd think that Java would be Java, but you'd be wrong -- the .jnlp file it sends down differentiates between architectures and OS's, and grabs a .jar file from the target which it then runs. I could hack around that (e.g. edit the OS section of said file before executing it) but (1) that's messy and (2) it doesn't work because the .jars have hard-coded references to shared libraries and thus blow up.

I tried loading SuperMicro's "self-contained" application which I can get to run but it also won't start the KVM for the same reason.

It thus appears that what I need to do is load the actual Linux java runtime. I do have Linux emulation working; Thunderbird is working fine under Gnome's desktop. But there is no package support for a Linux Java version that I can find and the ports version is extremely old (and requires hand-grabbing the old blob from Oracle); those old versions are deprecated for a (usually good) reason security-wise.

Thus the operative question is "how do I get around that", which I think means being able to load an "arbitrary" Linux package -- in this case, a reasonably-current java runtime, which I can then tell Firefox to redirect jnlp files to and it *should* work. I don't see anything in the ports tree that will "play" yum or apt-get.... any hints appreciated!

Thanks in advance!
I figured it out, but not the way I expected.

I got the IPMIView20 software to run. It has an "included" jre directory, and with the correct set of Linux X11 libraries loaded it operates. Since it's running the Linux "java", it is able to start the Java console applet, and all is well.

This one might help other people -- SuperMicro makes nice boards, but their KVM software is a 5-alarm pain in the butt if you're not on Windows, OS/X or (certain) Linux releases.....
Just been searching for this as I have a similar issue. I don't want to install things I'm only going to use once in a blue moon though. Fortunately there's a usb3 port on this machine so my solution has been to just install a linux to a usb key that has java that works with $vendors applet and boot to it when needed.
I pretty much have to work everyday with SupeMicro's shit for iKVM. The solution was to install a very old Ubuntu in VirtualBox and use a very old java version. Now, IPMIview kind of works.