/usr/share/mime-info/icedtea-netx-web-start.keys is in icedtea-netx-common 1.5.3-0ubuntu0.14.04.1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | application/x-java-jnlp-file
description=Java Web Start Application (IcedTea)
icon_filename=sun-java
default_action_type=application
default_application_id=java-web-start
short_list_application_user_additions=java-web-start
|