ha ! got it working !
how i've done it:
1/ no need to sign anything
2/ start tweaking the demo from the jlwgl applet loader (its in the full build)
Because i don't want 2 specific implementations (versions one for dpt and one for applet)
you can add a switch to know which mode you need to load
Config switch if applet or not:
gc instanceof AppletGameContainer.Container ?
((AppletGameContainer.Container) gc).getApplet() : null);
if isn't an applet i search for the user profile directory to persist (serialize my objects)
related to UAC / administrator rights on your system,
if it is an applet i can't serialize objects because this is out of the sandbox security
what you can do is, serialize your objects Base64Endoded to a cookie !
et voila it runs !