Oracle Forms 12c - Webstart

I'm using my own icon jar to load icons in my oracle forms application. I'm using webstart method to run my application. While using my application link JNLP file downloaded automatically and run the application, but icons are not loaded.

I add my my_icon.jar in extensions.jnlp file also but not loaded in my application.

I signed my my_icon.jar also.

Where I mentioned the jar file to load icons to my applicaiton.

Thanks

R. Kalai